选区激光熔化成形VNbMoTaW难熔高熵合金工艺研究

Selective Laser Melting and Forming VNbMoTaW Refractory High Entropy Alloy

采用选区激光熔化技术制备了VNbMoTaW难熔高熵合金,研究了激光工艺参数对VNbMoTaW难熔高熵合金试样的表面成形质量、微观组织和力学性能的影响。结果表明,当采用较高的功率和较低的扫描速度时,可有效改善VNbMoTaW试样表面质量,其中孔隙和裂纹是选区激光熔化技术制备VNbMoTaW难熔高熵合金的主要缺陷。VNbMoTaW难熔高熵合金组织主要由柱状晶和胞状晶组成,底部和中心大多为柱状晶,而熔池的两侧及顶部主要为胞状晶。VNbMoTaW的最高极限抗压强度可达2154 MPa,相比电弧熔炼方式制备的合金强度提高了69.6%。

The VNbMoTaW refractory high entropy alloy was prepared using selective laser melting.The effect of laser melting parameters on the surface forming quality,microstructure,and mechanical properties of VNbMoTaW refractory high entropy alloy specimens were investigated.The results show that the surface quality of the specimens can be effectively improved when a higher power and lower scanning speed are used,where porosity and cracks are the main defects in the preparation of the VNbMoTaW refractory high entropy alloy using selective laser melting.The VNbMoTaW refractory alloy mainly comprises columnar and cellular crystals,the bottom and central areas are mostly columnar crystals,while the sides and top of the melt pool are mainly cellular crystals.The maximum ultimate compressive strength of VNbMoTaW can reach 2154 MPa,which is 69.6%higher than that of alloys prepared using arc melting.