Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ames lab alloy could boost next generation jet fighter

06.01.2006


Materials Preparation Center Creates Stronger, Lighter Aluminum Alloy



The next generation of jet fighter aircraft could fly farther and faster thanks to a new high-strength aluminum alloy prepared at the U.S. Department of Energy’s Ames Laboratory. The new alloy is one material being developed for use in the F-35 Joint Strike Fighter, a cutting-edge aircraft that will see widespread use as the primary fighter for the U.S. Navy, Air Force, and Marines as well as U.S. allies abroad.

Researchers at Ames Laboratory’s Materials Preparation Center will produce about 400 pounds of an aluminum-yttrium-nickel alloy over the next few months that will serve as a benchmark for testing and to help refine commercial production techniques. The material is being developed in conjunction with aircraft engine manufacturer Pratt & Whitney and a number of other public and private partners to replace heavier or costlier components in the “cool” sections of jet engines. The material also could be used in other parts of an aircraft such as wing spars.


“When it comes to aircraft design, you want the strongest and lightest materials to get the most efficiency,” said MPC Director Larry Jones. “We (the MPC) have the expertise, processing capabilities and high purity raw materials to develop an alloy that performs up to the requirements for this project.”

If the new material performs up to expectations, it could have a dramatic impact on the performance and efficiency of both commercial and military aircraft. Jones said that Pratt &Whitney engineers estimated that replacing various components in one particular jet engine with the Al-Y-Ni alloy could potentially lighten the engine by 350 pounds. That’s an astronomical weight reduction in aircraft design, where engineers are typically happy to reduce the weight of components by a few pounds here or there.

“It means being able to carry significantly more fuel or payload,” Jones said. “It could also mean lower production costs,” pointing out that a bulkhead currently milled from a solid block of titanium for the JSF takes months to fabricate.

The alloy is produced using a process called high-pressure gas atomization. Pioneered at Ames Laboratory in the 1990’s by metallurgist Iver Anderson, the HPGA process uses a special nozzle to blast a stream of molten alloy material with a pressurized gas such as helium or nitrogen. The result is powder-fine metal particles that are highly uniform in chemical composition and, because they cool so quickly, exhibit the amorphous structure of the liquid metal rather than the crystal structure normally found in bulk metals.

The powdered metal is currently vacuum hot-pressed and hot extruded, a process that bonds the particles together while retaining some of the amorphous structure. This partially amorphous, partially crystallized structure gives HPGA-produced materials improved properties, such as strength and ductility. Preliminary tests of the MPC’s Al-Y-Ni alloy show it far exceeds anything commercially available. The top commercial aircraft-grade aluminum has a tensile strength of 70,000 pounds per square inch while this alloy has exceeded 100,000 psi in repeated preliminary tests.

Tests of the Al-Y-Ni alloy produced by a commercial manufacturer, however, have yielded less desirable results in the 90,000-92,000 psi range. While the basic “recipe” is the same, Jones said there are a number of inherent problems that ultimately affect the strength.

“Aluminum powders are used as rocket fuel so they’re highly explosive,” Jones said. “By using nitrogen gas in our process, it creates a nitride passivition layer so the powders are less likely to be explosive. This nitride layer breaks down during sintering, resulting in very strong bonds between the particles.”

By contrast, Jones explained that the commercial process injects oxygen into the atomization gas stream to create a controlled oxidation of the powders. While the oxidation layer reduces the explosiveness, it remains during sintering, resulting in weaker bonds between particles.

“Purity of the materials going into the alloy also affects the overall strength,” Jones said. “Any exogenous material will result in a weaker end product and that includes any oxidation that takes place.”

To address this problem, the material being produced by the MPC will be kept in an inert environment until after the vacuum hot pressing process is completed. The MPC has modified its HPGA system to capture the powder in a container under an inert atmosphere. The powder will be sieved to less than 32 microns in size in an inert atmosphere glove box before being shipped in a sealed container to DWA Aluminum Composites, Los Angeles, where the vacuum hot pressing process will be completed. After vacuum hot pressing the pressed and sintered powder billet will be extruded. Only then will it be exposed to the normal atmosphere. The results will be studied to help modify and improve processing at the commercial level.

Funding for the production of the material – approximately $475,000 – comes from Pratt & Whitney and the Defense Advanced Research Projects Agency, the central research and development organization for the Department of Defense. DARPA manages and directs selected basic and applied research and development projects for DOD, and pursues research and technology where risk and payoff are both very high and where success may provide dramatic advances for traditional military roles and missions.

“This all came about as a result of basic materials research funded by the (DOE’s) Office of Basic Energy Science,” Jones said. “It’s exciting to see the atomization process we developed advance to this point where it can make a real contribution to a project like the JSF and potentially the entire aviation and aerospace industry.”

Ames Laboratory is operated for the Department of Energy by Iowa State University. The Lab conducts research into various areas of national concern, including energy resources, high-speed computer design, environmental cleanup and restoration, and the synthesis and study of new materials.

Kerry Gibson | EurekAlert!
Further information:
http://www.ameslab.gov

More articles from Materials Sciences:

nachricht Scientists channel graphene to understand filtration and ion transport into cells
11.12.2017 | National Institute of Standards and Technology (NIST)

nachricht Successful Mechanical Testing of Nanowires
07.12.2017 | Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>