High compression strength pure tungsten fabricated by plasma arc additive manufacturing

Pure W were fabricated by wire plasma arc additive manufacturing technology (WPAAM) and systematically investigated in terms of the microstructure and mechanical property. The as-fabricated W exhibits large-size columnar grains along the deposition direction, and it has extremely few microcracks, compared with that fabricated by laser powder bed fusion (LPBF). The compression strength and compressive plastic deformation capability of WPAAM W are significantly improved compared to the widely studied LPBF W and the fine grained W fabricated by other processes. In particular, the strength of WPAAM W is comparable to that of ultrafine grained W. A microstructure-based predictive model of compressive strength is developed to understand the strength performance of AM W. The proposed model correlates the manufacturing process, microstructure and mechanical property of additive manufactured W. This study is expected to shed light in the development of additive manufacturing technology of refractory metals.