Principal investigator: Wei Xiong

University: University of Pittsburgh

Industry partner: The ExOne Company

Beam-based 3D printing methods with intrinsically complex cooling and heating processes easily introduce cracks during processing. Binder jetting additive manufacturing (BJAM) can easily avoid thermal cracking with less concern for residual stress. However, it is challenging to perform effective sintering on tungsten due to its high melting point. Although some new tungsten alloys have been developed to introduce liquid-phase sintering, these alloys have low strength with the maximum service temperature below 1300°C. This project proposes a new concept to advance BJAM technology for tungsten alloy—pure tungsten with alloy binder—with high mechanical performance above 1300°C. The University of Pittsburgh will collaborate with the ExOne Company to perform BJAM of tungsten for high strength at room temperature and 1200°C. In order to achieve this goal, there are three objectives in this project: (1) design a new refractory alloy binder to assist sintering of tungsten, (2) develop a BJAM process for tungsten alloy printing, and (3) perform post-heat treatment design to reach desired strength and ductility of printed tungsten alloy. The expected outcome will enable the Pennsylvania manufacturing community with new capabilities and generate new 3D printing products directly useful for defense, nuclear energy, and aviation engineering.