选区激光熔化成形射频等离子体球化钽粉的微观组织与力学性能研究

Microstructure and mechanical properties of selective laser melted pure tantalum using radio frequency plasma spheroidized powder

摘要:

本文采用射频等离子体球化法制备的球形钽粉进行选区激光熔化(SLM)成形致密化研究。通过工艺参数优化,在扫描速度为650 mm/s和激光能量为240 W条件下,获得了完全致密的钽样件。由于原始粉末具有较高的流动性,激光成形钽样件表现出较好的成形性能和表面质量。微观组织表征结果显示,样件顶面和侧面分别呈现等轴晶和柱状晶。EBSD结果表明,在制造方向呈现<111>择优取向。最高显微硬度和抗拉强度分别达到296.2 Hv和697 MPa,致密样件的延伸率也显著提高到28.5%。

Abstract:

In this study, spherical tantalum powder fabricated by radio frequency plasma spheroidization system was used for selective laser melting densification. Through optimizing the processing parameters, the fully dense Ta sample was obtained at the scanning speed of 650 mm/s and the laser power of 240 W. Attributed to the high sphericity, the Ta samples performed better densification behavior and surface quality. Microstructure characterization showed that equiaxed grains and columnar structure were present in the top- and side- views, respectively. The EBSD results revealed a <111> preferred orientation along the building direction. The maximum microhardness and the ultimate tensile strength reached 296.2 Hv and 697 MPa, respectively. A significantly improved ductility with elongation of 28.5% was achieved for the dense sample.