A new high-strength aluminum-silicon alloy developed at NASA’s Marshall
Space Flight Center, Huntsville, Ala., promises to lower engine emissions
and could improve gas mileage in cars, boats and recreational vehicles.
The new alloy, co-invented by Jonathan Lee, a NASA structural materials
engineer, was originally developed for the automotive industry.

Although most Americans associate NASA with space flight, one of the space
agency’s missions is to share its cutting-edge technologies with U.S.
industry. “Partnerships with U.S. industries are the main way NASA
transfers these technologies to the public,” explains Vernotto McMillan,
deputy manager of Marshall’s Technology Transfer Department.

Lee and Chen came up with MSFC-398, a wear-resistant alloy that exhibits
dramatic strength at temperatures as high as 500 to 700 degrees
Fahrenheit. In fact, when tested at 600 degrees Fahrenheit, it is three to
four times stronger than conventional cast aluminum alloys. The new metal
also can be produced at a projected cost of less than $1 per pound.

NASA High-Strength Alloy can be poured as a molten metal into conventional
steel molds or die-casting molds to create specially shaped parts — a
cost-saving advantage over machining of parts.

“The new alloy is ideal for high-temperature cast components used in
engines such as pistons, connecting rods, actuators, brake calipers and
rotors,” said Lee. This makes NASA High-Strength Alloy a good choice for
high-temperature applications in the automotive, aerospace, marine and
recreational vehicle industries.

“Increasingly stringent exhaust-emission regulations for internal
combustion engines have forced piston designers into a redesign to lower
emissions,” said Lee. “The current modification is to reduce the piston’s
crevice volume — the air gap between the piston wall and the cylinder
bore — by moving the top piston ring closer to the top of the piston
crown.”

Such a modification promises to be a key to reaching the goal of making
today’s high-performance gasoline and diesel engines meet tougher exhaust
standards.

To accomplish this, engine makers needed a strong, low-cost alloy that
would allow them to make the piston-crown depth thinner — yet still curb
piston failure caused by high work and heat loads.

“NASA High-Strength Alloy offers greater wear resistance and surface
hardness which enables manufacturers to use less material, thus reducing
the part’s weight and cost and improving gas mileage, engine performance
and engine durability,” said Lee.

Two U.S. patents have been awarded with other domestic patents pending. An
international patent is pending for the technology as well, said Sammy
Nabors, the commercialization lead in the Marshall Technology Transfer
Department. Through NASA’s Technology Transfer program, non-exclusive
licenses to develop new products from the improved alloy have been awarded
to Advanced Materials Technology Inc., Manitowoc, Wis.; Swan Metal
Composites Inc., Woodinville, Wash.; and Eck Industries, Manitowoc, Wis.

NASA is continuing to seek U.S. industries as partners to further transfer
this technology to the public and private sector.

For more information on the Marshall Center’s Technology Transfer program,
please visit their Web site at
http://techtran.msfc.nasa.gov/