电子束选区熔化成形高强钽的组织与性能

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

摘要:

采用粉末床电子束选区熔化技术制备了高密度（99.93%）且无明显缺陷的块状钽样品，并对其微观结构、力学性能进行了研究。结果表明，沉积态的钽金属具有平行于生长方向的柱状晶结构。由于成形过程中的高冷却速率，在块状样品中观察到（001）织构和大量的小角度晶界。由于间隙元素氧和氮的固溶强化，电子束选区熔化成形的钽试样表现出了优异的室温屈服强度（613.55±2.57 MPa）和延伸率（30.55%±4.23%）。

Abstract:

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%.