Microstructure and Properties of High Strength Tantalum Prepared by Selective Electron Beam Melting

Bulk tantalum specimens of high relative density (99.93%) without obvious defects were prepared by powder bed selective electron beam melting (SEBM) process, and their microstructure as well as mechanical properties were investigated. Results show that the as-deposited tantalum specimens have strong columnar grain structures parallel to the building direction. The strong (001) texture and a large number of low-angle grain boundaries can be observed in the bulk specimens due to the extremely high cooling rate during additive manufacturing. Because of the solid solution strength of interstitial oxygen and nitrogen elements, the as-SEBMed tantalum specimens exhibit excellent room-temperature yield strength of 613.55 +/- 2.57 MPa and outstanding elongation of 30.55%+/- 4.23%.