In this study, selective laser melting (SLM) of pure tantalum (Ta) was systematically investigated, with emphasis on densification, microstructure and mechanical properties of Ta specimen. The high laser scanning speed resulted in micropores and discontinuous scan tracks, owing to the elevated instability of the liquid induced by Marangoni convection and the balling effect. However, the interlayer thermal microcracks were produced at a low scanning speed, due to the thermal stress and balling effect. The microhardness and tensile strengths of the optimally SLM-processed Ta parts were improved to 445 HV and 739 MPa, respectively, which were considerably higher than specimens processed by cast (110 HV and 205 MPa) or powder metallurgy (120 HV and 310 MPa) method, due to the fine-grain strengthening. The fracture morphology of the tensile-failed SLM-processed specimens showed that the porosities and incompletely melted particles are responsible for the fracture of porous sample. While for dense sample, cleavage fracture and minor ductile fracture both account for the fracture. And the failure mechanisms were discussed. The reduced coefficient of friction of 0.3 and lowest wear rate of 7.1×10⁻³ mm³ N⁻¹ m⁻¹ in dry sliding wear tests were obtained for the optimally prepared Ta parts due to the formed adhesion of hardened tribolayers.

在这项研究中，系统地研究了纯钽（Ta）的选择性激光熔化（SLM），重点是Ta样品的致密化，微观结构和力学性能。由于Marangoni对流和球形效应导致的液体不稳定性增加，因此高的激光扫描速度导致了微孔和不连续的扫描轨迹。然而，由于热应力和滚珠效应，层间热微裂纹以低扫描速度产生。经SLM最佳处理的Ta零件的显微硬度和抗拉强度分别提高到445 HV和739 MPa，远高于铸造（110 HV和205 MPa）或粉末冶金（120 HV和310 MPa）的试样方法，由于细晶粒强化。拉伸失败的SLM处理试样的断裂形态表明，孔隙率和不完全熔化的颗粒是造成多孔试样断裂的原因。对于致密的样品，乳沟断裂和轻微的韧性断裂都是造成断裂的原因。并讨论了失效机理。降低的摩擦系数为0.3，最低磨损率为7.1×10由于硬化的摩擦层的形成的粘附力，对于最佳制备的Ta零件，获得了在干滑动磨损试验中的^-3  mm ³  N ^-1  m ^-1。