Cold Spray Additive Manufacturing of High Strength Precipitation Hardened Alloys

Cold spray additive manufacturing (CSAM) is a solid-state additive manufacturing (AM) process that produces consolidated parts by accelerating powder particles to supersonic speed and impacting against a substrate material to form a mechanical bonding. Unlike the directed energy deposition (DED) or powder bed fusion (PBF) processes, the feedstock can retain the optimal microstructure in the CSAM during and after deposition due to the solid-state nature of the process. This makes CSAM especially suitable for precipitation hardened (PH) alloys including Copper alloys, PH stainless steel, and Nickel-based superalloys. In this work, the heat treatment for the feedstocks is optimized for improved deposition in CSAM. The post deposition heat treatment parameters are also optimized for each alloy for improved consolidation and properties. The microstructure and properties of the CSAM parts are investigated using a combination of various microscopy, compositional analysis, mechanical testing procedures; and the results show that with right heat treatment and processing parameters, CSAM parts can result in cast and forge replacement properties in near net shape.