Three Texas A&M professors are pursuing crucial research on shape-memory alloys — materials that can mend their shape in response to their environment.

Shape-memory alloys are popular in a range of industries including aerospace and health, and their development was accelerated last month when NASA awarded a $500,000 grant to the A&M team to study their production. These alloys, sometimes called “smart metals,” are lightweight materials that can be deformed and restored to their original shape when heat is applied.  

“These are materials that literally have a memory,” said Alaa Elwany, principal investigator of the team. “If it is subjected to some temperature or some abnormal stress then it regains its original shape.”

These alloys are already being used as heart stints in cardiovascular surgery and are replacing complex parts in airplane engines, said Raymundo Arroyave, a materials science professor and team member. In fields that require complicated machines and precise movement, fewer moving parts often mean less failure.

These special alloys are produced by a process of additive manufacturing, better known as 3D printing, that allows advantages otherwise not feasible by conventional techniques.

“The advantage of additive manufacturing is that it provides the flexibility to basically design the shape you need to meet the functional requirements,” Arroyave said.

The problem, Elwany said, has been perfecting the 3D printing manufacture technique.

“It’s a material that has a lot of potential applications, but it is not easily manufactured,” Elwany said. “One major challenge is that there is very high variability. You use the same raw material, the same machine to produce the same parts and then you get different parts over and over again. This research is mainly concerned with trying to reduce this variability.”

NASA awarded the team’s proposal this month with the $500,000 grant through its SpaceTech-REDDI research initiative, a program launched by the agency to study smarter materials for space flight. Elwany, Arroyave and third team member Ibrahim Karaman will use the money to hire doctorate students and purchase advanced instruments to study the manufacturing process, according to a press release by the College of Engineering.

Elwany has already used some of the money to purchase an advanced temperature sensor from Stratonics, Inc. that is being installed this week and should help the team study what causes the variability in the material. Looking to the future, Elwany said the research will likely need more grants down the road.

“We are wrapping up a follow-up proposal that we will present to the National Science Foundation,” Elwany said. “Now we are characterizing the material, we are reducing the variability. Next we will produce actual parts for use.”

Elwany said he believes that no matter the cost, the work they are doing is worthwhile.

“This is one of the futures of this country,” Elwany said. “We are trying to foster this advanced manufacturing.”

Quelle: thebattalion