3D Printing of Refractory Alloys for Missile and Space Applications

Refractory alloys have extraordinary resistance to heat and wear. With superior durability, are often the desired material for extreme environment applications such as space craft, missiles, and hypersonic vehicles. Due to the difficulty and high cost associated with manufacturing in complex shape, their utilization has been hampered even in the most demanding applications. Additive Manufacturing, 3D printing, on the other hands has demonstrated a superior shape producing capability that is unattainable with traditional manufacturing processes. Develop and mature 3D printing of refractory metal alloys would greatly enhance the extreme environment product’s performance and lowering the cost. In this NASA and private industry collaborative research and development work, successful 3D printing of high quality Niobium C103 alloy components have been demonstrated and hot fire tested. The properties of 3D printed Nb C103 were compared to its equivalent wrought product, including the effect of heat treatments on microstructure evolution and materials properties. The 3D “as-printed” microstructures were extremely stable and largely intact even after 2 hours at 2900°F which is often exceeded this material’s application demand. Superior properties of 3D printed Nb C103 were observed from room temperature to elevated temperature. Hypothesis for such stable microstructures is proposed and validated. This work demonstrated a robust 3D printing process with superior materials properties, significant leap in producing highly sophisticated geometries, and sufficiently lowered manufacturing cost. A case study of performance gain in sophisticated Nb C103 engineered hardware will also be presented.