US-based QuesTek Innovations LLC has been awarded six separate projects from the US Navy and Army to develop technologies and design new alloys tailored to additive manufacturing (AM).
These include one Small Business Innovation Research (SBIR) Phase II project, two SBIR Phase I projects, and three Small Business Technology Transfer (STTR) Phase I projects focused on aluminum, titanium and steel systems. The combined funding contract value exceeds US$2 million.
According to the company, many alloys being evaluated in AM were originally designed for forging or casting processes and exhibit technical problems when used in AM. To address these design challenges and industry needs, QuesTek has been applying its integrated computational materials engineering (ICME) technologies and materials by design methodologies to design new alloys and optimize legacy alloys for AM.
Corrosion resistance
The awarded projects include developing three QuesTek-designed aluminum alloys specifically for direct metal laser sintering (DMLS) AM processability. The goal of this program is to combine the processability of AlSiMg alloys, which can be printed without cracking but have low strength, with the high strength properties of 6061/7050 alloys but which crack during AM processes. The alloys that QuesTek designed in the Phase I program cover a range of strategies for improved performance including increased strength, temperature resistance, corrosion resistance and resistance to hot tearing. Preliminary results have shown successful elimination of hot cracking coupled with high precipitation hardening results. Two designs were selected for atomization at 400 lb scale and DMLS builds are currently being evaluated under various mechanical and corrosion tests.
Under another Navy project, the company will be developing a new powder specification for high-strength martensitic precipitation-hardenable 17-4 stainless steel specifically for selective laser melting (SLM) technologies, to meet mechanical performance requirements and address AM processing issues experienced by incumbent materials. Under this program, QuesTek is collaborating with LPW Technology, Dr. Thomas Starr of the University of Louisville’s Rapid Prototyping Center, and OEM partner Sikorsky Aircraft.
Another project involves developing an integrated model toolkit to enable the modeling of AM process by predicting local composition, microstructure, residual stresses, defects, and mechanical properties for stainless steel 316L aerospace components. Under this program, QuesTek is collaborating with Professor Wayne E. King of Lawrence Livermore National Laboratory and Professor Gary Harlow of Lehigh University.
QuesTek has also been working on other projects including modeling of Ni, Ti and W-based alloys for AM.
‘A materials-based approach to addressing the challenges of additive manufacturing is crucial for accelerating the development of this technology and achieving, or even surpassing, the performance of traditionally-processed alloys,’ said Aziz Asphahani, QuesTek’s CEO. ‘We look forward to the outcomes of these projects, and the prospect of adopting ICME-designed alloys as the first-generation, high-performance additive manufacturing materials.’
This story is reprinted from material from QuesTek, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier.
