Next-Generation Steel for Additive Manufacturing

Despite the growth of metal additive manufacturing (AM), there has been limited research in developing new materials and alloys that could further enhance AM processes. However, the University of Pittsburgh's Swanson School of Engineering has received a three-year award of $449,000 from the Office of Naval Research (ONR) to explore next-generation metals, especially steel, for use in AM.

The research, "Integrated Computational Materials Design for Additive Manufacturing of High-Strength Steels Used in Naval Environments," will be led by Wei Xiong, assistant professor, Swanson School's Department of Mechanical Engineering and Materials Science. The team will also include Esta Abeley and Susheng Tan as the senior personnel supporting materials microstructure characterization and corrosion tests. Funding is provided by the ONR Additive Manufacturing Alloys for Naval Environments (AMANE) program to design, develop and optimize new metallic alloy compositions for AM that are resistant to the effects of the Naval/maritime environment.

"There are several metals, from nickel alloys to aluminum and titanium, which are the foundation for AM production of complex parts with properties that could not be developed via traditional, or subtractive, manufacturing. However, many of these materials are not as strong or reliable in the harsh environment of the sea, and that's a disadvantage for the Navy and other maritime agencies," Xiong said. "…our research will focus on developing new toolkits to leverage the use of new steel prototypes in AM that will benefit the U.S. Navy."

In particular, the Physical Metallurgy and Materials Design Laboratory led by Xiong will design a new type of high-strength low-alloy steel, which can be widely used in naval construction. The ONR proposal's objective is for the Pitt researchers to apply the Integrated Computational Materials Engineering (ICME) tools to design both the composition of these allows and the direct metal laser sintering process, which is used in AM to fuse the metal powders into components. The research will also focus on post-process optimization, which can further improve the mechanical properties and corrosion resistance of these specialty steels.