Quadrus develops crack-free rhenium part using laser powder bed fusion
Breakthrough in additive manufacturing advances propulsion materials and meets DARPA “Hard” challenge
Quadrus Corporation’s Advanced Manufacturing Division has developed what it describes as the first successful laser powder bed fusion (L-PBF) process for printing fully dense, crack-free elemental rhenium, a material known for its extreme brittleness and resistance to conventional additive manufacturing methods.
Funded through a Small Business Innovation Research (SBIR) contract and supported by the Defense Advanced Research Projects Agency (DARPA), the effort was carried out under the U.S. Army’s oversight as part of a Direct-to-Phase II award. The project aimed to overcome the longstanding challenges associated with additive manufacturing of rhenium, which is often used in propulsion systems due to its high-temperature strength, stiffness, and melting point, but is prone to microcracking during the build process.
Quadrus reports that earlier L-PBF attempts consistently resulted in extensive cracking. Through systematic experimentation, parameter optimization, and analysis, the company says it isolated the root causes and produced crack-free rhenium without preheating the build plate. The company characterizes this as a significant achievement in refractory metal printing, often referred to in DARPA programs as a “DARPA Hard” challenge.
Because the new process eliminates the need for post-build heat treatment to resolve cracking, Quadrus states it can now fine-tune heat treatments solely to achieve target microstructures. In preliminary tensile testing, the company reports yield strengths exceeding 80 ksi, ultimate strengths above 130 ksi, and elongation beyond 20 percent in the as-built condition.
“This capability changes the game for propulsion system suppliers,” said Dr. Joe Sims, Director of Advanced Manufacturing at Quadrus Corporation. “Now, with fully dense, crack-free L-PBF rhenium, we can produce complex, high-performance structures that were once thought impossible.”
The company plans to continue refining the process and expand testing to evaluate performance under elevated temperatures.
