Dean Pierce of the Department of Energy’s Oak Ridge National Laboratory and a research team led by ORNL’s Alex Plotkowski were recognized by DOE’s Vehicle Technologies Office for developing novel high-performance alloys that can withstand extreme environments.
Pierce was recognized for developing 3Cr-XHTS steel, an alloy of chromium and other elements.
“We’ve had a great collaboration with Cummins, and working with them has allowed us to bring together the unique expertise at both ORNL and Cummins to develop 3Cr-XHTS,” Pierce said. “I was excited for our whole team that, after four years of hard work and some exciting results, we were recognized.”
3Cr-XHTS steel was developed for use in pistons that can withstand high temperatures, high loads and long wear periods for next-generation, high-performance, higher-efficiency internal combustion engines. Currently the most advanced steel alloy for high-performance engine pistons, 4140 steel is limited to applications where peak metal temperatures are below 500 C, making the material insufficient for use in future higher temperature engines.
“For the piston application, we needed to design a steel that is not only strong and oxidation resistant at high temperatures, but it also has to conduct heat well. One of the purposes for conducting heat is to keep the temperature at the combustion surface of the piston low enough so that the material doesn’t fail during operation,” Pierce said. “These properties are often in conflict with one another, meaning that when one property is improved, others can be degraded, and our team needed to overcome this metallurgical design challenge.”
Compared to the most advanced 4140 steel currently available, 3Cr-XHTS has 143% higher fatigue strength and about 75°C higher maximum operating temperature. Researchers used 3Cr-XHTS to produce piston crowns that passed Cummins’ toughest engine test.
In addition, ORNL’s DuAlumin-3D research team was recognized at the annual merit review for developing DuAlumin-3D, a lightweight aluminum alloy.
“Aluminum alloys were a really interesting problem space for us to work in,” said Plotkowski, senior R&D staff member and the project’s principal investigator. “The major challenge is that conventional wrought aluminum alloys, the ones that we use the most around the world as well as the ones that have the most attractive properties, are challenging to process with additive manufacturing.”
The alloy overcomes conventional challenges and withstands the extreme thermal conditions of additive manufacturing.
DuAlumin-3D has already been used to print pistons that successfully completed a severe engine test at ORNL. DuAlumin-3D owes its name to the dual reinforcement mechanisms enabled by the rapid solidification of 3D laser printing combined with a short heat treatment.
In less than three years, the technology evolved from a concept to its current state as a viable material for additively manufactured prototypes and products.
“It was necessary to collaborate in order to make this project happen,” Plotkowski said. “It’s, in my opinion, an example of the kind of unique thing that ORNL can do that few other organizations in the world can do because we’re bringing together this diverse skillset. We’re able to easily pull people from all across the organization to contribute.”
Together with General Motors and Honda Performance Development, the alloy is being further developed for use in vehicle components.
The ORNL team and its partners also received a 2022 R&D 100 Award for DuAlumin-3D.
Other team members who received awards include Amit Shyam, Ryan Dehoff, J. Allen Haynes, Larry F. Allard, Sumit Bahl, Ying Yang, Jon Poplawsky, Bill Peter, Derek Splitter and Jiheon Jun of ORNL; Richard Michi of Owens Corning, who previously worked at ORNL; and Kevin Sisco of the University of Tennessee, Knoxville.
Subscribe to our Newsletter
3DPResso is a weekly newsletter that links to the most exciting global stories from the 3D printing and additive manufacturing industry.
