Matériaux, procédés, Technos et machines .

Bonjour !

Les Fuzzy fibers selon Goodrich ...
Pour les nacelles et sûrement d'autres applications, les bords d'attaque par exemple !
Un exemple desévolutions des fibres de carbone mixées au Nano-Matériaux !
pour la grèle, la conductivité et le dégivrage !
Les évolutions des CFRP ne font que commencer !

--------------------------- L'article AINonine -------------------------

http://www.ainonline.com/news/single-ne ... ich-25531/

Fuzzy fiber to lower cost of composites, says Goodrich

By: Stephen Pope
July 21, 2010
Aerospace Industry

Goodrich Corp. (Stand OE4) has begun collaborating with researchers at an Ohio university to produce a nanomaterial nicknamed “fuzzy fiber” that has metal-like conductive properties and can be formed into large composite structures for use in aerospace.

The University of Dayton Research Institute (UDRI) is collaborating with Goodrich and two other companies, Renegade Materials and Owens-Corning, to build a lab where researchers can produce the nanomaterial–known by the scientific name NAHF-X–in resin composite sheets.

URDI gets the credit for inventing NAFH-X. Now, Goodrich hopes to use the hybrid composite material in new-generation engine nacelles and will explore other applications, including aircraft structural health monitoring, wheels and brakes and electrical de-icing systems.

What intrigues engineers is NAFH-X’s ability to deliver structural, electrical and thermal properties in a single structure. An engine nacelle made from NAHF-X, for example, could withstand lightning and hail damage while also providing protection from ice buildup. Besides reducing weight and complexity, this would also provide a more efficient alternative to ice-removal systems that use hot-air ducts, Goodrich said.

The breakthrough that led to the creation of NAHF-X occurred when researchers determined how to control the growth of the nanotubes to create large, uniform structures with properties suitable for products like engine nacelles. So far, the UDRI research team has demonstrated it can produce the materials in continuous sheets that are 12 inches wide. The goal is to increase the size of the resin sheets to 60 inches wide.

“UDRI’s NAHF-X fuzzy fiber is a game-changer,” said Harry Arnold, vice president, enterprise technology, at Goodrich. “It has a real potential of bringing affordable capability to composite production.”

Goodrich has committed $1 million to the fuzzy-fiber program. Goodrich’s Aerostructures team in Chula Vista, California, and its Materials and Simulation Technical Center in Brecksville, Ohio, will be tasked with evaluating potential business opportunities for the material.

JPRS

Bonjour !

Bon, on l'a vu passer chez FG, pour ALCAN !

Le point sur les Aluminiums et leurs alliages !
Cette fois, ALCOA, qui eux aussi proposent des AlLi, qui peuvent apporter 3-14 % d'écos de poids !
Et ..; 1 A380 = 9 A320 pour la conso d'alu !

Long article de fond intéressant
A lire pour le week-end !

----------------- AINonline l'Article ---------------------

http://www.ainonline.com/news/single-news-page/article/aluminum-remains-relevant-despite-trend-toward-composites-25431/


Aluminum remains relevant despite trend toward composites

By: Gregory Polek
July 20, 2010
Aerospace Industry

Notwithstanding the unprecedented scale of composites content in the Boeing 787 and Airbus A350XWB airliners, aluminum still reigns as the material of choice in most airliner fuselage applications. At least that’s the message Alcoa–the aluminum company–wants to send here in Farnborough, where scores of examples of flying machines made of the metals the company supplies grace the static display.

Of course, the use of carbon-fiber products doesn’t preclude the use of aluminum and various other more exotic metals in the same airplane. Even what many consider an all-composite fuselage in the 787 uses thousands of highly specialized and expensive metallic fasteners made by Alcoa. In fact, according to Bill Christopher, Alcoa executive vice president and group president of the company’s Engineered Products & Solutions division, the dollar value of Alcoa’s contribution to the 787 virtually equals that of the aluminum-bodied 767.

Unfortunately, delays to the 787 and the A380 along with pressures such as inventory de-stocking and a collapse in the regional and business aircraft markets resulted in less demand for Alcoa’s aerospace products last year, when sales fell from $4 billion in 2008 to “just north of $3 billion.” However, the company’s financial position looks better this year, said Christopher. “If you look at the de-stocking on the jet engine side, that’s behind us; we’ve seen a pickup in the MRO, the replacement side of the business,” he added. “I think that de-stocking through that whole supply chain is done.”

Thankfully, the underlying fundamentals of the large commercial aircraft business “held up very well” all along, said Christopher, and Alcoa remains bullish about its prospects for the next two to three years, as manufacturers proceed with planned build rate increases and the 787 and A380 programs “ramp up to run rates.” Still, he said, “it will be later this year, early next year before we start to see any significant activity back there again.”

Three years ago Alcoa had just finished adding sheet and plate capacity at its Global Rolled Products division mills in Davenport, Iowa; Kitts Green, UK; Fusina, Italy; and Belaya Kalitva, Russia. The additions accounted for some 50 percent capacity expansion. Today, not only Alcoa, but the entire industry faces an overcapacity situation, particularly on the plate side, [but] “less so on extrusions,” said Christopher. “[In terms of] fasteners and airfoils, there’s some excess capacity but not nearly to the same extent, and most of that is driven just by business jet and regional jet demand.”

About half of the company’s portfolio consists of its traditional aluminum structural businesses it started a century ago. The other half consists of its Howmet jet-engine investment castings unit and its Alcoa Fastening Systems (AFS) division.

Proprietary Technology
Although Christopher wouldn’t reveal what proportion of Alcoa Aerospace’s revenue now comes from proprietary products, the company clearly has moved away from commodity markets and into proprietary technology. In 2004, proprietary products accounted for 12 percent of Alcoa’s aerospace revenue; in 2007 that share rose to more than 20 percent.

“If you ask what holds together a portfolio of jet engine parts, fastening systems and sheet, plate and extrusions for aluminum structures, it is technology,” said Christopher. “We look at each individual segment, we want highly complex applications where, in fact, we expect mission requirements to increase demands on the product, which allows us to develop technologies that solve customer problems.”

Christopher explained that the economic rationale for replacing equipment lies more firmly today with the cost savings that come with technology improvements than with direct acquisition cost savings the OEMs sought for earlier projects. The resulting demand for more sophisticated materials plays directly to Alcoa’s strengths. “Overall, it is clearly what we drive for, whether it’s proprietary, highly differentiated, a combination of technology or know-how or special dimensional characteristics,” he said. “And that really represents the core of all three segments of what we have.

“For the next five or six years we’re going to go through a renaissance in the industry, where you have all new platforms being run out,” Christopher predicted. “By 2020 you’re going to be talking about everything from twin-aisles to your super jumbo jets all being brand-new platforms.”

The next “battle ground,” according to Christopher, will involve the single-aisle segment, where Alcoa believes its metallic products will prove superior
to composites. Since Boeing launched the 787, Alcoa has developed three generations of aluminum lithium alloys, he said. Stronger than traditional aluminum, aluminum-lithium allows manufacturers to use thinner and, hence, lighter fuselage skins.

Incorporating Hybrids
Another area in which Alcoa believes it can compete with composites on weight involves so-called selective reinforcement, a concept that centers on strengthening certain fuselage points with hybrid material. “We’re now starting to look at single-aisle applications and saying we think that there’s anywhere between a 3-percent and 14-percent improvement on weight that can be delivered [with selective reinforcement],” said Christopher.

Whether or not aluminum- lithium or structural reinforcement technologies find their way onto new narrowbodies might well depend on the partnerships Alcoa manages to forge with OEMs. In fact, the company last year signed a strategic partnership agreement with Comac to help the Chinese company decide on what materials to use on the C919–the new 170- to 190-seat narrowbody scheduled for market introduction in 2016. “We have a full team of people working with their design people on really putting forth our best technologies in the design of that aircraft, from both a fastener perspective and an aluminum structures perspective,” said Christopher.

Of course, Alcoa has shown intense interest in the narrowbody strategies of Boeing and Airbus as well, along with the fortunes of the A380 and 747-8. The A380 alone consumes nine times the metal and alloys required by today’s 737 and A320. The largest supplier to the A380 program, Alcoa provides forgings, extrusions, sheet, plate and castings for the superjumbo’s wing and fuselage skins, along with stringers, frames, spars, gear ribs, engine and pylon supports, seat tracks and floor beams.

The AFS division has developed multi-material lock bolts for the assembly of the big jet’s wing box and new-generation blind bolts tailored for the program’s robotic assembly techniques. Each A380 uses about one million Alcoa fasteners.

“When you look at the prospects right now, the 747-8 and A380 [are] both metallic aircraft. They’re not going to change for 25 years,” said Christopher. “You’ve got the single aisles…obviously their lifespan is going to be longer than what everybody expected and we think we have incredibly competitive alternatives for them– especially given a single-aisle mission–that would provide them weight advantage and give them a lot more experience and predictability in both their design and their launch costs.”

Alcoa (Hall 1 Stand A9) can effect further weight savings by replacing titanium with advanced aluminum alloys. “Our fundamental belief is if you had a choice between aluminum and titanium, obviously you’re going to pick aluminum because it machines faster and it’s lighter,” said Christopher. “But then you’re trading off, in certain cases, strength” as well as titanium’s resistance to expansion at high temperatures. “The coefficient of thermal expansion between aluminum and composites unfortunately is very different,” he noted. “So there are places you just can’t put them together because, as the plane heats up or cools off, you’re going to end up with structural issues. So that’s part of the barrier that we face there.”

JPRS

J'aurais pu commencer par là !

Il y a 4 épisodes derrière !

http://www.compositesworld.com/articles/how-to-machine-composites-part-1----understanding-composites

Article From:, Peter Zelinski, Senior Editor

Posted on : 8/15/2008

Click Image to Enlarge



This Boeing 787 fuselage section is made entirely of composites.



How much composite material will be in the air? As this chart
from Composite Market Reports shows, the amount of composite material
in aircraft will more than triple during the next 10 years.

The Boeing 787 will be the world’s first large commercial airplane
made mostly of carbon-fiber composite materials. Composites make up 50
percent of the structural weight of the plane and something like 80
percent of the volume. By comparison, the Boeing 777 is just 11 percent
composites by weight. Boeing is making a huge commitment to replacing
metals with composites, and the economics of aircraft ownership explain
why.
For an airplane, the initial purchase price does not account for
the majority of the ultimate total cost of the plane. However,
maintaining and fueling the airplane together do account for the
majority of this cost, and composites bring down both of these expenses.
Aircraft composite materials are inherently more fatigue-resistant and
corrosion-resistant than metals, contributing to maintenance cost
savings that could be as high as $30 to 40 million over the life of a
787. The composite structures also deliver a greater strength-to-weight
ratio, contributing to fuel cost savings. It has been estimated that a
787 flying the same route as a 767 (a smaller plane) would consume $5
million less per year in fuel.
The total of these and other savings from composites comes
somewhere near the price of the plane. That observation has been
expressed this way: If the plane is made from composites, then you get
the plane for free.
Yet the dramatic shift in materials for aircraft parts entails a
similarly dramatic shift in the ways those parts are made. What
implications does a mostly-composite commercial airplane have for
manufacturing?
More specifically, what does this mean for machining?
A composite part is a near-net-shape part. The form is laid up onto
a tool that is custom-made to give the part its shape. Compared to an
aluminum aerostructure component, a composite part requires very little
machining.
Then again, the machining that the composite part does require can
be challenging indeed. By definition, composites are not homogenous the
way metal is. A “composite” is a combination of two or more materials
engineered to achieve better properties than either of the component
materials could achieve on their own. In a composite, one material is
the matrix and at least one other is the reinforcement. Carbon fiber
reinforced plastic (CFRP), the chief composite material in aircraft
parts, consists of a plastic matrix with carbon fiber reinforcement. The
shop that tries to machine this combination material faces a
combination of challenges. The matrix could melt from too much heat,
while the carbon fibers don’t cut well because they fracture instead of
shearing smoothly. Meanwhile, the CFRP structures are built up from
layers of material that could easily splinter or delaminate during
machining.
A final source of challenge is this: By the time the composite
structure is ready for machining, it has already become such a valuable
part that the cost of scrapping it may be enormous.
Therefore, as more composite parts come to market, a growing number
of machine shops will face this reality: They will machine composite
workpieces for which the amount of machining is small compared to a
metal part, but the cost, difficulty, value and impact of that machining
will be considerably higher.
It is not just Boeing driving this. Practically all aircraft
manufacturers are increasingly turning to composites to replace certain
metal components and assemblies. Helicopters have been mostly composites
for a while now. In fact, manufacturers of various high-value products
are increasingly looking to composites of one form or another to take
advantage of their strength, stiffness, durability, corrosion
resistance, wear resistance and light weight. One estimate says that in
10 years, there may be even more CFRP going into wind turbines than into
all aircraft. Meanwhile, metal matrix composites are being applied to
higher-performance automotive components such as brake rotors. And
because composites can also be transparent to X-rays, they are likely to
find many new medical applications as well.
However, the phrasing above—that industries are increasingly
looking to composites “of one form or another”—hints at an important
caveat when discussing this class of materials. That is, composites are
not a unified class of materials at all.
For example, CFRP is a type of polymer reinforced plastic, of which
there are many varieties. Other, similarly broad varieties of
composites are metal matrix composites and ceramic matrix composites.
The word “composite” actually refers to a broader range of materials
than the word “metal” does.
Earl Wilkerson, a CNC programming and tooling supervisor, has faced
various composites machining challenges as part of his work for General
Tool, a 240-employee contract manufacturer in Cincinnati, Ohio. A
composite, Mr. Wilkerson says, is “any two materials that someone wants
to glue together.”
How do you know how to machine a composite material that
you are facing for the first time? Quite likely, you don’t. That is part
of the reality of these materials. General Tool is something of a
composites machining expert at this point, having developed machining
experience in aircraft composites early on. Thanks to the company’s work
on an early jet engine that used composites, it has now been machining
aerospace composite materials for over 15 years. Even so, every new
composite part is still different to the shop.
In fact, every new CFRP part is different. The term “CFRP” itself
is broad. After General Tool succeeded machining its first CFRP part,
the company struggled with the second one, until it discovered that the
parameters needed to be slowed down and the leftover stock on some
features needed to increase. The properties and composition of the
second CFRP were different from the first CFRP—and this is the way it
has been with CFRP ever since.
“You can’t just go to a handbook and look up ‘composites’ to get
the right tools, speeds and feeds,” Mr. Wilkerson says. You can’t even
look up “CFRP.” None of these materials is defined or consistent enough
for that.
However, there are some lessons that this shop and other shops have
learned—lessons that have allowed them to consistently succeed at
machining a class of materials that continues to grow and change. To
proceed to the next article in this series, click here.
JPRS

Bonjour !

J'ouvre aussi un lien concernant le A350 !
Mach 3, c'est la vitesse du jet d'eau (Dans l'air je suppose, dans l'eau le son se propage plus vite )

http://www.mmsonline.com/articles/machining-at-mach-3

Article From: Modern Machine Shop, Peter Zelinski, Senior Editor

Posted on: 2/5/2009

The hard, solid cutting edge of a conventional end mill poses real dangers to the part whenever a tool such as this is used to cut carbon fiber reinforced plastic (CFRP). The impact and mechanical stresses can produce separation of the layers of material or pull-out of the carbon fibers. That is why, instead of tools with edges, shops often use abrasive milling tools to machine CFRP—tools that look like they are part grinding wheel and part end mill. High spindle speeds give tools such as these an efficient abrasive machining effect.

Yet there is another step beyond this. There is another option that achieves abrasive machining at even faster speeds. While an abrasive milling tool in a fast spindle might reach a cutting speed equivalent to about 50 miles per hour, an abrasive waterjet machine delivers the abrasive across the workpiece at a speed of about Mach 3. The difference is significant to Airbus, among others.

In order to develop lighter, more efficient and more durable planes, Airbus is increasingly applying engineered composite material to aircraft designs. The airframe of the new A350 XWB (“Xtra Wide Body”) aircraft is more than 50 percent composite materials by weight. CFRP components include the wings, fuselage, empennage, spars and keel beam—all of which will be machined using abrasive waterjet. The aircraft maker recently awarded Flow International a $30 million contract to build multi-axis abrasive waterjet machine tools at its Indiana facility for use in aircraft production plants throughout Europe.

Jose-Luis Morazo-Perez is head of A350 manufacturing engineering automation for Airbus, based in Hamburg, Germany. He says the company’s production facilities often use CNC routers and other rotary-tool machines to machine composites. Such machines were considered for this application as well. However, abrasive waterjet offered a clear economic advantage in the A350 XWB application. The abrasive and other consumables cost less than the cutting tools and other comparable consumables that would be needed to mill the parts. The cost of machine time was also less, because the faster cutting means the part spends less time on the machine.

“This was the best economical approach considering both recurring and non-recurring costs,” Mr. Morazo-Perez says.

He adds that further savings are likely to come from eliminating a costly step. Parts machined on a rotary-tool machine typically require deburring, even if the parts are cut with abrasive. But with waterjet, the cutting action is much faster and more thorough.

“Our expectation is that we could eventually avoid the deburring operation,” he says.

In other words, instead of achieving merely acceptable cutting that avoids the worst dangers such as delamination, the company sees hope for machined edges that are clean enough for the composite parts to be considered finished as soon as the waterjet cutting is done.

Waterjet In Action

Mark Saberton, chief engineer for Flow International, says these advantages that Airbus cites—faster cutting and avoiding damage to the workpiece—are among the main benefits aircraft manufacturers seek through machining composites with waterjet. Other benefits include:

• No dust. Fine dust from machining composites can infiltrate controls and other electronic equipment in the shop. It also makes the shop grimy and unappealing. With waterjet, this dust is contained and controlled. For the most part, the dust is carried away with the water, from which it can later be removed.

• No heat-affected zone. Delamination and fiber pullout are not the only dangers of mechanical cutting. Another is heat, which might melt the matrix of CFRP. But waterjet is inherently a cool process. Heat generation is slight, and the water transports the heat away.

• No rigid clamping. An unsupported edge of a CFRP workpiece is prone to vibrate during milling. For this reason, machining of composite structures on routers or similar machines often involves elaborate tooling designed to carefully and rigidly clamp the work at every trimmed edge. Vacuum fixturing built to the precise contours of the part is common. But with abrasive waterjet, the force of cutting is slight. The force also pushes down against the support beneath the part. Therefore, while programmable workholding is sometimes used (see below), rigid custom tooling is not required.

Aircraft Equipment

That “programmable workholding” is one of various features Airbus specified to allow its waterjet machines to be adapted to the particular needs of complex aircraft parts. Work is supported atop a flexible header system consisting of an array of effectors that resembles a bed of nails. Each effector’s vertical position is set independently, so the overall array can follow the contours of the part. Changing from one part number’s positions to the programmed effector positions for a different part takes only about 2 minutes, Mr. Saberton says. This compares very well to the hours that might be required to move one custom fixture off the machine and replace it with another hard fixture. Mr. Morazo-Perez says Airbus initially questioned this approach to workholding—worrying in particular whether the flexible tooling would stand up to the water over time. The company became convinced after visiting shops using similar programmable workholding on waterjet machines in the U.S.

Other machine features particular to aircraft abrasive waterjet machining include:

• Side-fire nozzles. Aircraft skins can include small ribs and stringers that impede access. The machine’s ability to switch to a nozzle that redirects the jet to the side can be useful for cutting within these tight spaces.

• C-catcher. The contours of aircraft structures can double back upon themselves, meaning the jet of water exiting the cut might hit some other surface of the part. To prevent this, a C-shaped catcher (see photo) can intercept the exit side of the jet. A consumable inside of this device absorbs the energy of the jet so the water can be captured and reclaimed.

• Rotary spindle. As Airbus indicated, rotary-tool machining remains useful in many composites applications. In fact, certain features must be machined in this way. While waterjet can machine a hole, for example, it can’t machine a countersink. Therefore, some abrasive waterjet machines incorporate rotary spindles for such needs as this. The rotary spindle is also useful for marking tools.

Mr. Saberton says one other, even more significant advantage of having such a spindle available is that it allows the machine to use a probe. This can permit further consolidation of steps, he says—allowing the waterjet machine itself to inspect the part before it leaves the machine.

JPRS

Bonjour !

Un petit tour chez Aerolia , à Méaulte !

Des infos intéressantes !
Ou comment on réduit un lingot de 1500 KG d'alu Li en un cadre de pare brise de 27 kg !
Merci les CNC 5 axes, et Catia ! Impressionnant quand même !
J'espère que la récupération des copeaux (Sans pollution) est au point pour refondre !
Pour les coûts, ben quand on aime ... les poids légers, on ne compte pas !
Signé, les Weight Ripoux !
Noter que pour ces pièces hyper délicates, et partie importante de la sécurité de l'avion, ben Airbus a volontairement zappé le CRFP, qui serait bien mois cher ! Zéro risque de ce côté !

-----------
The 1st cockpit window frame At
Méaulte, the 1st A350XWB window frame was presented to Aerolia's Airbus
Customer on 7 July. A key part of aviation cockpits, the window frames
are integrally machined to provide this exposed section of the aircraft
with the required stiffness.
Three
5-axis machines controlled by CATIA, produce these frames automatically
in compliance with quality and weight requirements. Machined from an
aluminium blank weighing 1.5 tonnes, the A350XWB window frame is
machined down to 27 kg for a thickness of 22 cm, a length of 1 m 82 and a
width of 1 m 36. All the cockpit window frames for all the aircraft of
the different Airbus families are produced here at Méaulte.
------------
Et d'autres infos à lire !

http://composites-survey.blogspot.com/2010/08/aerolia-mix-of-composites-and-metals.html

JPRS

Bon, ça sort comme ça sort de mon excel !

Bonjour

La technologie "Graphènes" bien moins chère que le nanotubes !

Pour !

- La tenue en température !

- La conductivité, pour les retours de courant, et la foudre par exemple !

- Des pistes pour le futur de l'aviation et les weight ripouxteurs et les électriciens !

- Excellent pour contrer les micro criques et micro fractures, ca peut aider à Grottaglia !

----------------------------

http://www.technologyreview.com/computing/20821/page1/

Polymers can be infused with carbon nanotubes to make materials with similar properties. But graphene could be much cheaper. "You can buy [graphite] in bags for dollars a pound, while single-walled nanotubes are hundreds of dollars per gram," says Catherine Brinson, a mechanical-engineering professor at Northwestern University, who led the work, which was published online in Nature Nanotechnology.

Graphene might also raise fewer toxicity concerns than carbon nanotubes. A separate Nature Nanotechnology study has found that long carbon nanotubes cause the same toxic reactions in mice as asbestos. The worry is that carbon nanotubes could mimic asbestos fibers, which are thin enough to penetrate into the lungs and cause cancer. Graphene, on the other hand, "is a nanometer only in thickness," says Lawrence Drzal, director of the Composite Materials and Structures Center at Michigan State University. "They're relatively large in two other dimensions. They won't be able to go through blood brain barriers or into cells."

Graphene-polymer composites would be ideal for making lightweight gasoline tanks and plastic containers that keep food fresh for weeks. They could also be used to make lighter, more fuel-efficient aircraft and car parts, as well as stronger wind turbines, medical implants, and sports equipment. What's more, they are good electrical conductors and could be used to make transparent conductive coatings for solar cells and displays.

The advance is part of a broader research effort to make nanoparticle-embedded polymers. Carbon and glass fibers have traditionally been used to strengthen polymers-- fiberglass is a common example. Unlike with fibers, though, a very small amount of nanoparticles--less than 2 percent of the composite's volume--is enough to make the polymer stronger and heat resistant. Because less filler is used, the composite can retain the polymer's stretchability or transparency.

-----------------------

http://www.nature.com/nature/journal/v442/n7100/abs/nature04969.html

Graphene sheets—one-atom-thick two-dimensional layers of sp2-bonded carbon—are predicted to have a range of unusual properties. Their thermal conductivity and mechanical stiffness may rival the remarkable in-plane values for graphite (3,000 W m-1 K-1 and 1,060 GPa, respectively); their fracture strength should be comparable to that of carbon nanotubes for similar types of defects1, 2, 3; and recent studies have shown that individual graphene sheets have extraordinary electronic transport properties4, 5, 6, 7, 8. One possible route to harnessing these properties for applications would be to incorporate graphene sheets in a composite material. The manufacturing of such composites requires not only that graphene sheets be produced on a sufficient scale but that they also be incorporated, and homogeneously distributed, into various matrices. Graphite, inexpensive and available in large quantity, unfortunately does not readily exfoliate to yield individual graphene sheets. Here we present a general approach for the preparation of graphene-polymer composites via complete exfoliation of graphite9 and molecular-level dispersion of individual, chemically modified graphene sheets within polymer hosts. A polystyrene–graphene composite formed by this route exhibits a percolation threshold10 of 0.1 volume per cent for room-temperature electrical conductivity, the lowest reported value for any carbon-based composite except for those involving carbon nanotubes11; at only 1 volume per cent, this composite has a conductivity of 0.1 S m-1, sufficient for many electrical applications12. Our bottom-up chemical approach of tuning the graphene sheet properties provides a path to a broad new class of graphene-based materials and their use in a variety of applications.

---------------------------------

http://www.compositesworld.com/news/three-studies-highlight-benefits-of-graphene-composite-structures

According to the studies, conducted by Rensselaer Polytechnic Institute, composites infused with graphene are stronger, stiffer, and less prone to failure than composites infused with carbon nanotubes or other nanoparticles

Posted on: 5/4/2010

Rensselaer Polytechnic Institute (Troy, N.Y., USA) announced on April 26 three new studies by its researchers that illustrate the benefits of graphene to strengthen composite materials used in everything from wind turbines to aircraft wings.

According to the studies, composites infused with graphene are stronger, stiffer, and less prone to failure than composites infused with carbon nanotubes or other nanoparticles, “I’ve been working in nanocomposites for 10 years, and graphene is the best one I’ve ever seen in terms of mechanical properties,” said Nikhil Koratkar, professor in the Department of Mechanical, Aerospace, and Nuclear Engineering at Rensselaer, who led the studies. “Graphene is far superior to carbon nanotubes or any other known nanofiller in transferring its exceptional strength and mechanical properties to a host material.”

Koratkar’s team has infused composites with stacks, or platelets, of graphene. Each stack is only a few nanometers thick. The research team also infused epoxy composites with carbon nanotubes. Epoxy materials infused with graphene exhibited superior performance. In fact, adding graphene equal to 0.1 percent of the weight of the composite boosted the strength and the stiffness of the material to the same degree as adding carbon nanotubes equal to 1 percent of the weight of the composite. The graphene fillers also boosted the composite’s resistance to fatigue crack propagation by nearly two orders of magnitude, compared to the baseline epoxy material.

Koratkar said graphene has three distinct advantages over carbon nanotubes. The first advantage is the rough and wrinkled surface texture of graphene, caused by a very high density of surface defects. These defects are a result of the thermal exfoliation process that the Rensselaer research team used to manufacture bulk quantities of graphene from graphite. These wrinkly surfaces interlock extremely well with the surrounding polymer material, helping to boost the interfacial load transfer between graphene and the host material.

The second advantage is surface area. As a planer sheet, graphene benefits from considerably more contact with the polymer material than the tube-shaped carbon nanotubes. This is because the polymer chains are unable to enter the interior of the nanotubes, but both the top and bottom surfaces of the graphene sheet can be in close contact with the polymer matrix.

The third benefit is geometry. When microcracks in the composite structure encounter a two-dimensional graphene sheet, they are deflected, or forced to tilt and twist around the sheet. This process helps to absorb the energy that is responsible for propagating the crack. Crack deflection processes are far more effective for two-dimensional sheets with a high aspect ratio such as graphene, as compared to one-dimensional nanotubes.

For more information on Koratkar’s research, visit www.rpi.edu/~koratn.

---------------------------

Vu à la télé, merci Fujitsu !

https://www.youtube.com/watch?v=munIqrfGMZg

JPRS

Bonsoir !
Pour faire plus simple :
Wikip !

http://en.wikipedia.org/wiki/Graphene

A part cela, moins ils en parlent, plus ils sont dessus, les graphènes, A et B ! Weight Ripoux oblige !
Bonne lecture !

JPRS

Bonjour !

Un petit tour dans les alliages de magnésium, utilisés jusqu'aux années 50' War oblige ... et abandonnés depuis, et remis en lice, par divers programmes Européens !
Gros défaut, inflammable vers les 700°, mais seulement quand ils fondent ... on est déjà cuit, en gros !
Nouveau, les protections anti-corrosion, et un peu "Fire, pardon Melt retardantes"
Et toujours, 20-30% de gain de poids, Vs l'Alu, et des caractéristiques mécaniques très intéressantes, dans des gammes de T° normales, bien sûr !
Soudable, formable,et 4 fois plus léger que l'acier à résistance égale !

Une alternative intéressante aux composites ... qui progressent très vite ! Pas sûr !

Peut être attendre les coûts et taxes de recyclage pour les avions "Composite" L' Arizona en voudra t'il toujours, faut voir ??

Juste à lire :
http://www.materials.manchester.ac.uk/pdf/research/latest/magnesium/elke_hombergsmeier_AEROMAG%20Paper_07.pdf
Et ...
http://www.aviationweek.com/aw/blogs/aviation_week/on_space_and_technology/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=a68cb417-3364-4fbf-a9dd-4feda680ec9c&plckPostId=Blog%3Aa68cb417-3364-4fbf-a9dd-4feda680ec9cPost%3Ae9b7b218-6fae-4590-9ee5-adc870c84efb&plckScript=blogScript&plckElementId=blogDest
Et ...
http://www.gov-online.go.jp/pdf/hlj_ar/vol_0032e/28-29.pdf
Et ...
http://www.luxfer.com/news-article.asp?id=113
Et ...
http://www.magnesium-technologies.com/var/249/76511-PRESENT%20STATE%20AND%20FUTURE%20OF%20MAGNESIUM%20APPLICATION%20IN%20AEROSPACE%20INDUSTRY.pdf
Et ...
http://www.magnesium-technologies.com/var/249/76510-PAPER%20-%20PRESENT%20STATE%20AND%20FUTURE%20OF%20MAGNESIUM%20APPLICATION%20IN%20AEROSPACE%20INDUSTRY.pdf
Et ...
http://www.palbam.co.il/magforming/magforming_publications.files/MAGFORMING-%20Development%20of%20New%20Magnesium%20Forming%20Technologies%20for%20the%20Aeronautics%20Industry.pdf
Bonne lecture !

JPRS

Bonsoir à tous,

Je viens de trouver ça, une nouvelle sorte de panneau composite :

Un composite de papier novateur pour l’aéronautique

Les panneaux d’intérieur semi-structurels des avions fabriqués avec des feuilles de résine polyétherimide peuvent être thermoformées en quelques minutes, sans aucune finition secondaire, et offrent une durée de vie double de ceux en composites thermodurcissables renforcés de fibres d'aramide en nid d’abeilles.

Les pièces d’intérieur semi-structurelles des avions sont généralement réalisées en composites thermodurcissables renforcés de fibres d'aramide en nid d’abeilles. Malheureusement, ces composites étant extrêmement sensibles à l'humidité et aux rayons ultra-violets, les bords perméables des pièces doivent être laborieusement comblés et scellés à la main, un procédé qui peut prendre jusqu’à 10 h de travail. SABIC Innovative Plastics a donc profité du salon Aircraft Interiors Expo Americas qui vient de se tenir à Seattle, pour proposer sa résine polyétherimide UItem sous forme de feuilles co-développées et fabriquées avec Crane & Co., le leader mondial des papiers de spécialité.
Les feuilles en Ultem CAB pour panneaux aéronautiques peuvent être thermoformées en quelques minutes, sans aucune finition secondaire En plus des cycles de production plus rapides, elles réduisent encore les coûts du système par leur capacité à être re-surfacées tout en conservant les propriétés de Flamme - Fumée - Toxicité (F-F-T) et en respectant les exigences de la Federal Aviation Administration (FAA) : il suffit de poser une nouvelle couche de film décoratif sur la surface pour allonger leur durée de vie. Autre avantage, leur faible poids : les feuilles d’UItem CAB qui pèsent en moyenne 1.350 g/m², peuvent être personnalisées pour satisfaire aux exigences d’une vaste gamme de poids de pièce.
« Avec la feuille d’Ultem CAB, SABIC Innovative Plastics et Crane apportent des avantages considérables par rapport aux composites traditionnels en nid d'abeilles, d’une part en réduisant la durée de cycle de production et d’autre part en doublant la durée de vie de la pièce, » affirme Kim Choate, responsable marketing des produits Ultem, SABIC Innovative Plastics. « La résine Ultem était la solution dont nous avions besoin pour créer un composite de papier novateur et techniquement avancé. Notre collaboration réussie avec SABIC Innovative Plastics nous a permis de diversifier notre portefeuille et de cibler une nouvelle opportunité de marché », complète Dennis Lockyer, vice-président des matériaux non-tissés et techniques de Crane & Co.
Les feuilles d’UItem CAB qui sont actuellement en cours d’essai pour une compagnie aérienne majeure, pourraient trouver leur place dans les parois latérales, les panneaux d’habitacles, les panneaux plafonniers, les revêtements intérieurs de portes et les parois de séparation des avions.

http://www.techniques-ingenieur.fr/actualite/materiaux-thematique_6342/un-composite-de-papier-novateur-pour-l-aeronautique-article_7707/

Je laisse aux spécialistes le soin de nous expliquer le pourquoi du comment !

Amicalement

Merci Julienaline !

Des feuilles, pourquoi pas ... mais de là a remplacer une structure nid d'abeille ... pour la rigidité, la résistance , l'isolation, et l'acoustique ... bien on verra à l'usage !
Ca reste à voir ... mais si ils reproduisent d'une manière ou d'une autre le nid d'abeille avec XX feuilles ... pourquoi pas !
Mais pour moi quand on parle Aramide, c'est le Kevlar, du plutôt sérieux et structurellement costaud ... bien que la face "Cosmétique", c'est le gel coat ...point plus sensible au vieillissement !

JPRS

Bonjour !

Jon Ostrower, de FlightGlobal est allé se promener à Denver !
Un paquet de conférences futuristes!
Une belle boite à outils pour Boeing, pour son futur 797 !
Voire s'ils prendront les risques (Après le 787) pour assurer une marge de 10 points ou plus pour contrer efficacement les 320 NEO ! Et pour quand !
Un avenir un peu fumeux pour l'instant... au vu du rythme des progrès, assez faibles, réalisés depuis 10 ans (Sauf pour les moteurs)
Surtout noté que les CFRP conducteurs ne sont pas prévus dans le court terme, et c'est un des vrais problèmes actuels !
Les nanotubes, bien, ça reste pour l'instant dans le rôle des additifs!
D'abord, c'est encore très cher !

Bon, en vrac ...

Le programme :
http://www.aiaa.org/content.cfm?pageid=230&lumeetingid=2412

L'article de JO :
http://www.flightglobal.com/blogs/flightblogger/

Des Slides, intéressantes, et plutôt ardues à suivre et à comprendre.
http://www.aiaa.org/pdf/industry/presentations/Charles_Harris_presentation_2011.pdf

Bon Shopping, après le tri c'est difficile d'identifier ce qu'une seule génération pourra voir !

JPRS

Bonjour

Après un célèbre cadre de bicyclette formé par des faisceaux d'énergie en 3D, dans une soupe primaire ... on se croirait dans la formation de l'univers !

Bien, EADS, veut développer cette techno avec GKN !
On reparle en plus des fan RR au passage, ben tout fini par arriver, même quand on est un peu dans le potage avec le poids des Fan Titane !!

------------ Le lien avec FlightGlobal, intéressant -----------

http://www.flightglobal.com/articles/2011/04/14/355571/eads-gkn-aim-to-bring-additive-layer-manufacturing-to.html

J'ajoute pour ne pas changer de rubrique ... une autre info Flightglobal !!

Le fuselage du Honda Jet sera fait en 2 parts "Collées" par le même GKN, aux USA !
Avec des délais qui laissent songeurs, pour une décision récente ....

http://www.flightglobal.com/articles/2011/04/14/355570/honda-picks-gkn-for-hondajet-fuselage.html

JPRS

Bonjour !

ENFIN !

Depuis le temps que je les attend !
Les nanotubes voient le jour sur un Avion ... le F35 !
Entrée "Timide" car peu ou pas certifiée pour les fortes charges !
Des essais trés avançés et intéressants chez Lookheed !
C'est bien, les autres n'auront plusqu'a prendre des licences,, AVIS A AIRBUS et A Dassault !
Combien de tonnes à gagner sur les A400M et A350XWB ??
Un train à ne pas laisser passer !
J'ajoute ... que ça me fait penser au bord d'attaque des aubes de FAN's, ça pourrait aussi être bien utile à SNECMA/Safran !

Une bonne cible d'investissement pour ceux (Ou celles) qui s'occupent du FSI, par exemple !
Les technos nanotubes étaient incubentes vers Grenoble, juste de mémoire !
Se sont elles développées ??

------------- A lire sur FG, Lien, et l'Article ----------------

http://www.flightglobal.com/articles/2011/05/26/357223/lockheed-martin-reveals-f-35-to-feature-nanocomposite.html

Lockheed Martin reveals F-35 to feature nanocomposite structures

By Stephen Trimble
Lockheed Martin has revealed the F-35 Lightning II will be the first mass-produced aircraft
to integrate structural nanocomposites in non-load bearing airframe components.

A thermoset epoxy reinforced by carbon nanotubes will replace carbon fibre as the material used to produce F-35 wingtip fairings beginning with low rate initial production (LRIP)-4 aircraft, said Travis Earles, a
manager for corporate nanotechnology initiatives.
Meanwhile, the same carbon nanotube reinforced polymer (CNRP) material is being considered to replace about 100 components made with other composites or metals throughout the F-35's airframe, he said.

The shift to CNRP as an airframe material has been anticipated ever since carbon nanotubes were discovered in 1991. It is widely considered one of the strongest materials ever invented - several times stronger
than carbon fibre reinforced plastic (CFRP), yet lighter by about 25-30%.

CFRP has come to rival aluminium and steel as a material for primary
structures: for instance, Boeing is building 787 fuselage barrels entirely from CFRP material.

But the widespread usage of CFRP for load-bearing components of commercial and military airframes only happened after two decades of development work.

That development cycle began in the early 1970s, when manufacturers began experimenting with glass and carbon fibre-based composites for secondary control surfaces.

Similarly, the introduction of CNRP in non-load bearing structures in the current decade, starting with the F-35, could lead to wider usage in airframe structures as the technology matures.

According to Earles, there is no technical reason the material could not be used in load-bearing structures. However, to reduce certification requirements of a structural material, carbon nanotubes are only being
considered in non-load bearing components.

In the meantime, the use of carbon nanotubes is already widespread in industries ranging from semiconductors to golf clubs. The high cost and complexity of producing the structures means they have so far had
limited applications in aerospace programmes.

Lockheed, however, has invented a process that dramatically reduces the cost to build carbon nanotube composites for aircraft structures, Earles said.

The new wingtip fairing is being made for one-tenth of the cost of the equivalent CFRP component, he said.
Earles declined to describe details of Lockheed's low-cost manufacturing process for carbon nanotube composites. Such particulars are considered trade secrets within the company, he said.

But it is clear that the cost-saving process is a relatively new invention within Lockheed. Earles said it has evolved within the past four years. During the same time period, Lockheed has been active in
developing new, low-cost methods for manufacturing airframe structures. Lockheed was selected by the Air Force Research Laboratory in 2007 to build and demonstrate the X-55 advanced composite cargo aircraft
(ACCA), which modified a Fairchild Dornier 328Jet. The fuselage was rebuilt with a new kind of carbon fibre resin that can be cured outside an autoclave, avoiding one of the most costly steps in the production of
CFRP materials.

It is possible that the X-55 airframe also benefited from the development work that produced the carbon nanotube composites, which are now being applied to the F-35.

The company is only now publicising the first details about the rapid progress in manufacturing nanostructures for airframes.
A display inside Lockheed's energy solutions centre in Crystal City, Virginia, shows off the F-35's new wingtip fairing derived from nanotechnology.
The material is identified as "advanced polymers engineered for the extreme - first generation", or APEX. It is described within the display as "best-in-class ultra-lightweight and affordable structural thermoplastic enhanced with nanoparticles that delivers increased mechanical properties, thermal stability, electrical conductivity and
processability over currently available projects".

JPRS

Bonjour !

Allez, ça avance un peu dans l'EU, côté "Curing" des CFRP ! En attendant les nano-particules, que l'on ne voit guère en Europe ! Hou Hou Lookheed un coup de main pour Airbus ??

Des panneaux des bord de fuite, des ailes du A350, ne passeront plus à l' Autoclave ! Chez advanced Composite, UK !
Une retombée des développements sponsorisés par l'EU ! C'est bien !
Pas d'indications techno ! Secret défense ? Juste OoA, out of autoclave, on est bien avancé !
Par contre, beaucoup moins de limitations à la production en série !
Boeing est sur la même voie, avec des chauffages par micro ondes !

----------- Dans le blog de Jon Ostrower, le lien édité --------------

http://www.flightglobal.com/blogs/flightblogger/2011/06/a350-composite-wing-panels-to.html

While all the attention at the Paris Air Show will surely be turned
to the airlines and the aircraft makers they will be shopping from, a
little known technology company called Advanced Composites Group Ltd., may be set to make a big impact on the future of commercial aerospace manufacturing in Le Bourget.


On display for the first time will be parts manufactured for the Airbus A350 XWB composite trailing edge wing panels.
While on its surface that may not seem particularly notable in an
aircraft that has 52% composite primary structure, each panel is made
from MTM44-1, the first application of out-of-autoclave (OoA) composite
technology for commercial aircraft structure.


The heavily infrastructure intensive process of curing composites at 180 degrees Celsius requires expensive massive autoclaves
to cook monolithic parts that seek to deliver a higher strength to
weight ratio over comparable metallic parts. The autoclaves are a
massive part of the cost of the capital expenditure for
majority-composite aircraft, along with the high cost to run the
high-temperature, high-pressure ovens for each shipset.


Boeing is currently in search of a method
of building an all-new composite narrowbody aircraft without
autoclaves, allowing for significantly higher production rates running
at 40, 50 or even 60 aircraft per month, while cutting both the
non-recurring and recurring cost to build each one.


It should not go unmentioned that the Advanced Low Cost Aircraft Structures
(ALCAS) program led by Airbus and Dassault, which helped to ready
MTM44-1 for production primetime, was funded by the European Union's
Framework Six program, explicitly mentioned in the Boeing WTO complaint.
In fact, the recent WTO appellate decision determined that the Framework Six program represented a specific subsidy,
but not one that was prohibited. The program represents a definitive
example of integrated stakeholders developing commercially viable
technology that further the goals of all the parties involved.


Though
as Boeing looks to make a decision about an all-new jet or re-engined
737 in the next nine months, a battle of aerospace materials is in the
works with significant news expected from metallics giant Alcoa in the
coming days as well, setting up Paris to see duelling technologies make
their case for large-scale commercial implementation.


However,
the battle doesn't necessarily represent polar opposite directions for
airframers, but rather finding the right application for both OoA and
advanced metals as each seeks to make make their case for not just new
jets, but also reducing the weight and cost for those already in
production.

JPRS

Bien vu, du Cousin Lequebecois ! Sur Aeroweb !

Un grand merci !

Magnifiques progrés !
Sur les AL-Li proposés par ALCOA ! On attendait l'annonce, ça tombe pour le Bourget !
Gros effet sur les MC à priori ! 12% à gagner en poids!

Juste une question, en dehorsde avions neufs qui devraient venir un jour avec ce nouvel AL-Li ??
Quelles sont les possibilités de l'incorporer et dans quelles proportions sur les MC existants ??
320-737 , par exemple !


Juste voir quand un projet constructeur sera lancé pour valider tout ça !

Je l'ouvre pour garder la trace !

http://www.alcoa.com/global/en/news/news_detail.asp?pageID=20110609005855en&newsYear=2011

---------------------------------------------

Alcoa Develops Breakthrough Technologies That Lower Cost, Weight and Production Risk of New Airplanes

New Alcoa Alloys and Advanced Structural Technologies:

- Provide Up to 10% in weight savings over composite-intensive planes;

- Lower the cost to manufacture, operate and repair planes by up to 30%
vs. composite- intensive planes… at significantly lower production risk;

- Allow for a 12% increase in fuel efficiency, on top of the 15% from new engines;

- Deliver passenger comfort features equivalent to composite-intensive
planes, such as higher cabin pressure, large windows and higher
humidity; and

- Market research shows 3 out of 4 in industry would recommend aluminum for future primary aluminum structures.

NEW YORK & PITTSBURGH--(BUSINESS WIRE)--Alcoa (NYSE:AA) today
announced it has developed a completely new set of aluminum-based
solutions for the aerospace market that will allow airframers to build
dramatically lighter and lower-cost short-range airplanes at
significantly lower production risk than composite-intensive planes.

The new solutions, which combine new alloys and advanced structural
technologies, use Alcoa sheet, plate, forgings and hard alloy extrusion
products across aircraft structures, including airplane wings and
fuselage elements. The new technologies:

- lower the weight of the plane by up to 10% vs. composite-intensive planes;

- lower the cost to manufacture, operate and repair planes by up to 30%
vs. composite-intensive planes, and at significantly lower production
risk;

- allow for a 12% increase in fuel efficiency, on top of the 15% from new engines; and

- deliver passenger comfort features equivalent to composite-intensive
planes, such as higher cabin pressure, large windows and higher
humidity.

“The decisions made in the past decade to build the first
composite-intensive aircraft were a huge wake-up call for us,” said Mick
Wallis, President of Alcoa North American Rolled Products who is
responsible for Alcoa’s aerospace sheet and plate products. “In
hindsight it was the right decision for the time – when advanced
aluminum solutions were not as developed -- but our technology solutions
have made quantum leaps since those decisions.

“And it’s important to keep in mind that the mission requirements of
short-range airplanes are dramatically different than those of
longer-range planes,” added Wallis. “With these new solutions we are
confident we can add value to airframers in their short-range offerings,
just as we have proven with longer-range planes…and the market research
we’ve conducted says we are not alone in that belief.”

The combination of Alcoa solutions results in short range aircraft that
meet or exceed airframer targets for corrosion resistance, aerodynamic
drag, maintenance requirements, and fuel efficiency along with improved
buy-to-fly ratios. In fact, the improvements developed by Alcoa
for a new short-range aircraft can generate up to a 12% increase in fuel
efficiency on top of the 15% improvement from new engines.

Included in the new solutions portfolio are advanced alloys and
third-generation aluminum lithium alloys that result in up to 7% lower
density in major structural applications along with critically important
corrosion resistance. Alcoa’s most-recent aluminum lithium alloys were
selected for large commercial aircraft plate applications and are being
used on planes about to enter the marketplace. These newest aluminum
lithium alloys provide additional enhanced performance.

New improvements in aerodynamics for skin sheet developed by Alcoa
reduce skin friction drag by up to 6%. In addition, new advanced
structural technologies using forged, extruded, and rolled products
enable increased wing aspect ratio for improved fuel savings, provide up
to 10 times the damage tolerance vs. conventional alloys, and allow
increased cabin pressurization for enhanced passenger comfort, on par
with all new aircraft structures in development today.

“As we began work on these new solutions, we wanted to ensure they
contribute to all four phases of a plane’s life cycle,” said Eric
Roegner, President of Alcoa Forgings and Extrusions. “In the first
phase, when it is built, we will lower manufacturing and assembly costs
and reduce program risks for the airframer through established high
volume supply chains and reduced investment requirements via existing
infrastructure…and aircraft operators want the reduced risk associated
with timely delivery.

“In the second phase, when customers fly the plane, the lower
weight and aerodynamic technologies will increase fuel efficiency by up
to 12% on their own and up to 27% when new engines are factored in,” said Roegner.

_________________
JPRS

Voir du côté du MRJ
Après, changer le matériaux sur un avion existant est-ce facile ?
Peut-être les panneaux de fuselage ? pour quel gain ?

Oui Poncho !

Pas facile sur l'existant !
Par petits bouts ou par grosses structures ??? Aile de A320 NEO, c'est peut être encore possible , Wingbox , Coque, avec des laminés type glare Al-Li ??!
On peut rêver , mais celui qui aura la plus forte pression, ira le plus vite ... !

Une refonte profonde "Surprise" des 737-320, vers 2018, pourquoi pas ... 2 milliards de plus Holé !
Les 737 sous la pression des 320 NEO, ou les 320 NEO sous la pression des 797, possible aussi !

Et aussi tout ce qui peut être grapillé sur les "Gros" et là la liste est infinie ! Il y a toujours 25 à 60 % d'alu dedans !
Pour le neuf ...

Le MRJ, hum, il est bien avancé !
Le prochain Embraer et peut être le 797 ! Sont les meilleurs candidats !
Une refonte profonde "Surprise" des 737-320, vers 2018, pourquoi pas ... 2 milliards de plus Holé !

QQ questions, hors poutres et laminés, l' Al-Li, est il utilisable en "Fonderie" disons , je pense aux pièces de train !

J'ajoute !

Bon, les Aluminium, toute catégorie ont perdu de grosses parts de marché dans l'aviation !
On est sur une contre-offensive de 3eme set, dans un match type "Rolland-Garros"
Il il en aura d'autres, d'énormes progrés sont à attendre des plastoc, quand les pris des nanotubes et des graphènes le permettront !
Ce n'est pas pour demain, donc les AL-Li ont encore une ou deux décades devant eux !

Bien adaptés ces AL-Li pour les petites et moyennes séries, évolutives, sans trop d'outillages, et avec un engineering en terrain connu !

JPRS

Bonjour !

Les Graphènes ! Vu sur A.net !
Les nanotubes, même combat !
Plus solides, plus conducteurs aussi !
Un matériel d'avenir pour l'aviation !

Lookheed expérimente et produit déjà des composites avec des nanotubes, sur de petites pièces ..;
Boeing dépose des Brevets !
Ou en est on en Europe ?? Rien vu today !
On la sentait pourtant venir celle là !

http://www.freepatentsonline.com/y2011/0108978.html

GRAPHENE NANOPLATELET METAL MATRIX

Document Type and Number:
United States Patent Application 20110108978
Kind Code: A1

Abstract:

A metal matrix composite is disclosed that includes graphene
nanoplatelets dispersed in a metal matrix. The composite provides for
improved thermal conductivity. The composite may be formed into heat
spreaders or other thermal management devices to provide improved
cooling to electronic and electrical equipment and semiconductor
devices.

Inventors:

Kim, Namsoo Paul (Bellevue, WA, US)
Huang, James Ping (Huntington Beach, CA, US)

Application Number:
12/614215

Publication Date:
05/12/2011

Filing Date:
11/06/2009

View Patent Images:
Download PDF 20110108978
PDF help

Export Citation:

Click for automatic bibliography generation

Assignee:

THE BOEING COMPANY (Chicago, IL, US)
---------------------
JPRS

Bonsoir !

Airbus a craqué pour les AL-Li de Alcoa !
Applications, hum, on verra, zero Info, secret défense !
Mais je doute que seuls les A350 soient concernés !
Un jour qq rétrofits vers les 320 et 330 !
A suivre !

http://www.foxbusiness.com/industries/2011/06/24/alcoa-wins-1-billion-deal-with-airbus/

U.S. aluminum producer Alcoa Inc said Friday it won a multiyear contract worth about $1 billion to
supply its new, lighter aluminum-based alloys for Airbus commercial aircraft.

The news sent Alcoa stock up almost 1.8 percent to $15.55 in early trading on the New York Stock Exchange on a day when the broader market fell. Later in the morning, the shares were up 8 cents to $15.36.

Alcoa said the deal with the European planemaker unit of EADS calls for Alcoa to provide aluminum sheet and
plate using current and advanced-generation aluminum alloys, which are lighter and stronger than traditional metals and composites.

Terms of the agreement, reached this week at the Paris Air Show, were not disclosed, but Alcoa said the agreement has a value of about $1 billion over its life.

Alcoa's [color:2dcc=blue !important][color:2dcc=blue ! important]aluminum [color:2dcc=blue ! important]products will be used on most Airbus commercial aircraft, from short-range,
single-aisle planes to long-haul jets, including the A380, the company said.

The aluminum, for fuselage panels and structural components as well as wing skins, will be supplied from
plants in Davenport, Iowa; Kitts Green, England; and Belaya Kalitva, Russia.

JPRS

Ben tant mieux non ?

Bonjour à tous,

Beochien a écrit:Des panneaux des bord de fuite, des ailes du A350, ne passeront plus à l' Autoclave ! Chez advanced Composite, UK !
Une retombée des développements sponsorisés par l'EU ! C'est bien !
Pas d'indications techno ! Secret défense ? Juste OoA, out of autoclave, on est bien avancé !
Par contre, beaucoup moins de limitations à la production en série !
Boeing est sur la même voie, avec des chauffages par micro ondes !

Peut-être ce genre de composites :

Des matrices thermoplastiques

Il s’agit de matrices, jusqu’alors employées en plasturgie, sans les renforts de fibres : les Peek (polyétheréthercéthone), les polyamides et les PET (polyéthylène téréphtalate). La réaction qui les solidifie n’est pas la même qu’avec les thermodurcissables, elle ne nécessite pas de mise sous pression. «Il n’y a plus cette complexité au niveaudu cycle de cuisson. On ne parle plus de précision des paramètres couplée à une durée de polymérisation longue. Il suffit de venir à la température de fusion, de mettre la pièce en forme et de la refroidir instantanément. Les cycles de production sont ainsi considérablement raccourcis », explique Laurent Juras, responsable de l’activité conception et industrialisation composites au pôle d’activité ingénierie des polymères et composites du Cetim. La matrice thermoplastique présente aussi l’avantage d’avoir un comportement déformable à une certaine température, qui permet de lui redonner de la viscosité. Une pièce peut donc être formée une première fois, puis réchauffée à température plus élevée pour être redéformée. «Cela offre des possibilités de réparation, d’assemblage par soudage. Là où l’assemblagemécanique coupe les fibres, avec les thermoplastiques on peut chauffer deux pièces, les mettre sous pression et générer un niveaud’accroche qui résiste aux efforts », constate Christophe Champenois.

Je n'ai pas ouvert tout le lien mais il est très instructif. A lire

http://www.industrie.com/it/aeronautique/les-composites-chassent-les-metaux.11660

Amicalement

Bonsoir !

Pompé directement du Cousin, chez Aweb !

------------------- Le post, et le lien !----------------------

http://www.aeroweb-fr.net/forum/aviation-civile/2364/15

Embraer a sélectionné Alcoa et ses nouveaux alliages Al-Li pour
améliorer ses E-Jets. Reste à voir le résultat final. Voici quelques
infos que j'ai trouvé à ce sujet :

http://www.alcoa.com/global/en/news/new ... sYear=2011
http://www.alcoa.com/aerospace/en/pdf/A ... e92011.pdf
http://www.alcoa.com/global/en/innovati ... 07_110.pdf
http://www.alcoa.com/adip/catalog/pdf/A ... hSheet.pdf

Et voici des infos sur les alliages Al-Li de Constellium baptisé Airware
sélectionné par Airbus pour l'A350 et Bombardier pour le CSeries :

http://www.constellium.com/business-sol ... ds/airware
http://www.constellium.com/news-media/n ... next-level
http://www.viadeo.com/hub/forums/detail ... 9tin8pgy28
https://www.dailymotion.com/video/xjhiat ... rware_tech

-------------------

Bien, Alcoa revient en force, et contre Constellium !

Airbus est chez les 2 ---- assez bizarre, le A350 est fait (A priori) chez Constellium ...
http://www.constellium.com/markets/aerospace/commercial-aircraft

Et il traîne (Airbus) 1000 millions d'engagements (Pluriannuel signé au Bourget) peut être pour 10 ans ! chez Alcoa ?
http://seekingalpha.com/article/278598-alcoa-earnings-company-may-guide-higher-boosting-others

Suivez mon regard :
A 10 $ le kg (A la louche, il y a des fasteners et certainement des pièces techniques ...
M'enfin ça fait jusqu'à 100 000 tonnes, même avec la moitié, ce sont des milliers avions ...

Bien, l'annonce vient d'Embraer, ce sera pour ses E-190 séries ... on va voir ce que ça coûte de modifier et recalculer tout l'avion ! Bombardier, qui se fait les dents sur le C-Séries, va devoir surveiller de prés !

Alcoa, annonce 10% de gains sur les poids, ce qui doit induire une réduction des épaisseurs !
Et 2% de mieux pour des qualités spécifiques d'écoulement de l'air ... pas trop compris le truc ...
Donc, 12% de gagné sur l'efficacité !
A ajouter aux 15% des nouveaux moteurs clame Alcoa (De quoi je me mêle, les motoristes sont plutôt à 12-13 %)

Bon, peut être 25% d'écos pour pour le E-195 en 2018 ! A suivre !

Gains attendus, aussi côté oxydations, entretien, résistance aux chocs etc ...là c'est la valse des estimations Mktg, hum !

Bien, entre A et B pour les MC, ça va être le chat et la souris !
Bien possible, un round de plus pour les MC de A&B , et de préférence pour saluer la sortie des C919, et MS-21, vers 2017-18 ! Holé !

Boeing n'a rien signé avec Alcoa (Officiellement du moins) Airbus, si, et pour beaucoup plus qu'il ne lui en faut avec le A350, qu'il fait d'ailleurs, avec de l'Al-Li à priori de chez Constellium !

Cherchez l'erreur, Airbus à passé un accord pour peut être jusqu'à 100 000 tonnes d'Al-Li, avec Alcoa, sans en avoir besoin !

Allez, qui sortira son NEO ou son MAX en Al-Li le premier ! Et à 25% d'écos, cette foi !
Les 330 aussi ... hum ! Mais sans remotorisation, ce serait idiot !
Et le A380 , au fait, lui, il va certainement re-motoriser un jour !

Allez, bonne nuit !

JPRS

Merci le cousin
Merci Beochien

Signer un contrat ne dit pas quelle proportion de nouveau matériaux peut être injecté dans une vieille carcasse...

Oui Poncho !

C'est la bonne question !
Mais pour que celà vale la peine il faut au moins toutes les peaux (Cellule et Ailes) et les longerons !
Et les couples si l'on veut aussi gagner sur la corrosion et l'entretien ...
Ca peut faire dans les 20 tonnes sur un MC ! 2 tonnes de gains ...
Bon, Alcoa annonçent 10-12% de gains de conso, ça me paraît un peu optimiste ! Un amalgame un peu rapide entre les % de gains de poids sur la structure et les économies de kéro !
Le mktg Alcoa y va allégrement surtout si l'on compare avec l'avion au MTOW par exemple !
Au passage Alcoa commente que les hublots peuvent être facilement agrandis !

Et à quelle prix d'études.... et de certification !
Pour moi le déclanchement, de l'Al-Li, ce sont les Russes et les Chinois qui vont le provoquer !

JPRS

Bonjour,

Mais pour changer le revêtement, les longerons et les cadres, cela nécessite de refaire complètement le design du fuselage. Selon moi, la seule utilisation possible sans tout refaire c'est de ne changer que le revêtement mais là, le gain de poids est sensiblement moins important. Il me semble que c'était écrit jusqu'à 10%...

Salut Paul

Je suis assez d'accord...
on ne doit pas pouvoir changer comme ça sans étude sérieuse ...