Like engineers in other transportation industries, commercial aircraft designers are racing to create lighter weight, less costly components while maintaining structural integrity. New materials for manufacturing structural and non-structural components are being developed for interior and exterior applications. These include lighter, stronger, and faster-curing carbon fiber and glass composites, and lighter weight metals and alloys. For interiors, new constructions contain microcellular or honeycomb cores or glass bubbles.
Although composites, especially carbon fiber-based, receive a lot of attention, most structural materials in commercial aircraft are still metals, primarily aluminum and its alloys. According to a new study of lightweighting materials in transportation, in many cases, aluminum is the best material for the short term, since it doesn't disrupt manufacturing patterns. The Lux Research report, "Structural Navigation: Optimizing Materials Selection in Automotive and Aerospace," contains multiple decision-tree analyses. These help determine which materials are best used where in several transportation applications, now and during the next 10 years.
Components made of microcellular polyurethane elastomers, such as this jounce bumper or spring aid made of BASF's Cellasto, can reduce weight, absorb shock, and dampen sound and vibration in aircraft interiors. (Source: BASF)
In the last five to seven years the aerospace industry has learned that carbon fiber doesn't make sense for every application, said Tony Morales, Alcoa's global marketing director for aerospace and defense rolled products:
From the design and build standpoint, aluminum has high performance and low weight at a lower cost than the alternatives. It doesn't require building new factories, new hangars, new supply chains, new ovens, or doing R&D for new inspection and repair techniques. In metal wing structures, you only have mass where it's needed. In carbon fiber it's harder to fine-tune complex shapes.
Alcoa is working with aircraft OEMs on new structural approaches that combine selective reinforcement techniques and advanced structural concepts with new materials.
Its third-generation aluminum-lithium alloys, introduced last year, have higher strength-to-weight ratios and better stiffness and corrosion resistance. Their densities range from 2 percent to 10 percent lower than traditional aluminum, depending on the amount of lithium. Most of the new generation is around 5 percent lower density. They are being used in extrusions, forgings, and sheet and plate applications in several aircraft structures, including airplane wings and fuselage. Alcoa expects to reach full production by the end of 2012 in two facilities, and by the end of 2014 in its Lafayette, Ind. facility.
Composite makers are also involved in major efforts to improve their materials as competition with aluminum alloys heats up. The main areas of development include improving strength and toughness, adapting component shapes to specific loads or environmental conditions, and reducing costs by finding better processing methods to speed up laydown rates, said Carmelo Lo Faro, Cytec's vice president of technology.
Very comprehensive overview of the state of materials exploration in the aerospace industry. It was interesting to me that companies don't see composites as the be-all, end-all solution--a surprise given that so much attention and hype is focused on their deployment. I was also pleased to see that companies are keeping somewhat of a watchful eye on sustainability concerns as they vet out these new materials.
Beth, I also found it enlightening to discover the mix of materials being developed for, and used in, in bleeding-edge aircraft design. But composites are, in fact, a big part of all this, so it's not all hype. It was a big surprise, and encouraging, to see that sustainability concerns are finally reaching and influencing this industry, like so many others.
It really shouldn't be a surprise that composites are not the be all and end all of advanced structures. Aluminum has served the aircraft industries well and is (relatively speaking) a fail-safe material...dings, dents and cracks are all fixable in aluminum....dings in composites you don't know about until you've got 12 feet of delamination flapping in the breeze. Dents require trepanning the damage out of the composite and rebuilding the location. Things like leading edges in composites are fine until you have a bird strike then it's easier to replace the whole leading edge. A bird strike on an aluminum leading edge is field fixable by any competent sheet metal basher...most get you home fixes are good enough for a number of flights since the pilot will be able to view the fix and make a decision on whether to fly. Try making the same decision on a composite fix and you don't know whether its good bad or indifferent. Alcoa et al are not going to go out of business because the new fad is composites...in fact they've still got a lot up their sleeves....variations in ARALL and GLARE are just two of the aluminum/composite hybrids that'll run circles around pure composites
I saw no mention of cellular steel (superalloy) products. Inside and near turbine engines, the temperatures are too high for most of the materials mentioned. In fact the temperatures seem to be rising, to the point that many parts that were traditionally made of titanium alloys are failing. For quite a few years, we've been working both on traditional superalloy honeycomb and on other brazed cellular structures that can replace titanium and withstand much higher temperatures, and yet be weight-neutral or even weight-saving.
CPDick, thanks for that information. We focused on structural and interior component materials for this feature, not engines, but that's good input. It's especially interesting that temperatures are outpacing titanium. Can you give us your company name for possible followup?
You bet! It's Vertechs Enterprises (vertechsusa.com)
I just looked, and realized that the non-honeycomb sandwich products are not yet shown on our website. We have a number of such products that we have been developing and testing with major aerospace companies for quite a few years, and are just about to start producing our first full-scale product samples.
sometimes new ideas generate new discovweries, consider a study of all species of bird feathers and the incredible design weight, lift, etc etc, flexible wings to use both mechanical power and atmospheric changes , perhaps the ultra lights culd take on a new perspective> my wing collection has some very old feathers that have not changed over time as I keep studing these designs which are incredible' I think there is legislation forbading feather collections, but I have a deep native american background, the race card and holocaust is not in my deck. My spirit remembers the genocide of americas 20,000 tribes, and the role buffalo soldiers played when freed. I worked for a time at LTV Aerospace in the 60's on the A-7 series, while no bird is powered with fuel they can indeed do some pretty tricky stunts, like gliding for hours, with small wing shifts , in acord with atmospheric variables, fins do compensate to keep on course, but consideration of actual feathers may be in our future. whatever. Birds of prey do reach considerable speed, without any fuel at all,
BASF's website at the link Susan gives below has a clickable overall diagram of the numerous types of plastics and other materials for an airplane manufactured by the company. While high-level, I found this info helpful in my background research. Clicking on any of the categories leads to a different diagram giving more detail. For example, the high-level diagram on the structural materials page
gives an idea of where different types of composites, thermoplastics, PIM and polyurethane materials might be used in an aircraft.
I see this technology as being useful in the manufacture of jackscrews, ths component that is often used to actuate control surfaces. If it was constructed of a lightweight plastic with a low coefficent of friction, this would be less inertia needed to move the jackscrew (energy saving for the drive motor) and could possibly lessen the need for lubrication substances. Remember the Alaska Airlines DC-9 that crashed due to failure of the jackscrew from inadequate/wrong tytpe of grease?
A new service lets engineers and orthopedic surgeons design and 3D print highly accurate, patient-specific, orthopedic medical implants made of metal -- without owning a 3D printer. Using free, downloadable software, users can import ASCII and binary .STL files, design the implant, and send an encrypted design file to a third-party manufacturer.
A recent report sponsored by the American Chemistry Council (ACC) focuses on emerging gasification technologies for converting waste into energy and fuel on a large scale and saving it from the landfill. Some of that waste includes non-recycled plastic.
Capping a 30-year quest, GE Aviation has broken ground on the first high-volume factory for producing commercial jet engine components from ceramic matrix composites. The plant will produce high-pressure turbine shrouds for the LEAP Turbofan engine.
Seismic shifts in 3D printing materials include an optimization method that reduces the material needed to print an object by 85 percent, research designed to create new, stronger materials, and a new ASTM standard for their mechanical properties.
A recent study finds that 3D printing is both cheaper and greener than traditional factory-based mass manufacturing and distribution. At least, it's true for making consumer plastic products on open-source, low-cost RepRap printers.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.