A University of Arizona engineering effort to make hypersonic vehicles faster and more affordable is getting a $3.1 million boost from the U.S. Army. The funding was awarded to a research group led by Sammy Tin, who holds the Patrick R. Taylor Endowed Department Leadership Chair in the Department of Materials Science and Engineering.

Tin and five U of A College of Engineering colleagues are exploring the use of multiple metallic alloys and additive manufacturing to enable fabrication of Mach-X – pronounced mock-ex – aerospace technologies as part of a federal governmental push. Mach-X vehicles will travel at speeds faster than Mach 5, which is five times the speed of sound and the hypersonic threshold.

"This important research partnership draws on the university's deep experience and strategic investments in hypersonics and is tied to an area of strategic importance for the university: advancing leadership in space sciences, space technology and national security," said Tomás Díaz de la Rubia, U of A senior vice president for research and innovation. 

The two-year project will advance additional national priorities and bring the Army closer to deploying Mach-X vehicles, said David W. Hahn, the Craig M. Berge Dean of the College of Engineering. The project also will train undergraduate and graduate engineering students to take on critical manufacturing roles across domestic industries.

The award provides the resources and coordination to make the most of college expertise, added Hahn. 

“I anticipate the research will increase the nation's capabilities related to homeland security, space exploration and technical manufacturing," he said. 

An end-to-end environment

Tin and Andrew Wessman, an assistant professor of materials science and engineering, have teamed up on a number of hypersonics projects and jointly hold over a dozen patents in alloy development. However, this is the first time the two are working in the university's Applied Research Building. The building opened in April 2023, providing the infrastructure to keep the university at the forefront of technological manufacturing and space sciences.

"The Applied Research Building gives us the resources to complete all the necessary steps in one place," said Wessman. "We can move quickly and form a comprehensive, end-to-end picture of what materials we can use, what processes work and what results we can achieve."

The research team – which includes Department of Materials Science and Engineering faculty members Krishna Muralidharan, Oana Cazacu and Benoit Revil-Baudard, plus Kavan Hazeli from the Department of Aerospace and Mechanical Engineering – will process two alloys and study their capacity to be shaped into the complex structures needed for ultrafast aircraft.

The alloys will be joined via 3D printing using compositional grading, in which the concentration of one alloy on the outside of a component gradually reduces to give way to a second alloy layer beneath. These components can be engineered to withstand extreme heat and stress, and also rapidly dissipate heat and minimize localized hot spots.

Tin's team plans to consolidate metallic powders into novel alloys using an advanced powder atomizer and multiple types of metal 3D printers housed in the Applied Research Building. The team is also constructing a lab in the building to test the materials' durability and strength at temperatures up to 2,200 degrees Fahrenheit.

Aligned with national priorities

Undergraduate students, graduate research assistants and postdoctoral researchers will assist the faculty members with materials testing, modeling and simulation over the two-year grant period. This work builds skills in high demand in government agencies and businesses, said Wessman. And specialized knowledge of emerging materials and processes will position the students to lead efforts to grow the U.S. manufacturing base.

"It benefits our country to have graduates who can apply this understanding across a range of industries that need experts. In addition to defense, they could go into fields like automotive or consumer electronics," Wessman said.

The research team expects the project to provide additional national advantages. A primary goal is to develop a knowledge base for 3D printing protocols that clarifies the costs and tradeoffs associated with materials and processes. This data will move the technology forward and enable producers to create components in nontraditional shapes that are affordable and practical. 

"The challenge right now is that the manufacturing supply chain doesn't exist. This makes hypersonic vehicle platforms incredibly expensive," said Tin.

The National Center for Defense Manufacturing and Machining is a project partner. NCDMM is a nonprofit that brings defense stakeholders together to improve and integrate technologies. For this research, the organization will provide expert guidance on meeting end users' needs, as well as a forum for sharing the insights gained with others working in the national interest.

Tin is confident that, in time, the hypersonic materials and protocols developed for the Army will make their way to space travel and commercial aviation.

"All flight structures have a lot of similarities to their geometries," he said. "The technology translates to many commercial applications that have tremendous impact on modern society."