VIGA法制备的M2052锰铜合金粉末及其SLM打印件的性能

Properties of M2052 Mn-Cu alloy powder prepared by VIGA method and its SLM prints

采用真空感应熔炼气雾化法(VIGA)制备了M2052锰铜合金粉末,分析了M2052锰铜粉末的物性和显微组织;用选区激光熔化3D打印技术(SLM)制备锰铜试样,并分析热处理前后SLM成型的锰铜合金的组织与性能。结果表明,VIGA法能够有效地控制金属粉末形状,制备的15~53μm粒度区间的锰铜粉末收得率高,松装密度高,具有较好的球形度,有效满足SLM用金属粉末的要求。由SLM制备的锰铜打印件横纵向具有不同的微观组织,随熔池内部延伸逐渐变为胞状晶,沿焊接界面形成柱状晶,离熔池越远柱状晶越细。与铸态合金相比,SLM方法制备的锰铜合金具有明显的力学性能差异,SLM打印件的抗拉强度为611 MPa,规定塑性延伸强度为504 MPa,远远高于铸态母合金的454 MPa和172 MPa。其原因是打印件细晶强化效果明显,但微裂纹的存在对塑性不利。

The M2052 alloy powder was prepared by the vacuum induction melting gas atomization(VIGA)method,and its physical properties and microstructure were analyzed.Then the Mn-Cu specimens were prepared by selective laser melting(SLM)technology and the microstructure and mechanical properties of the SLM printed specimens were analyzed.The results show that,the VIGA method can effectively control the shape of metal powders,and the VIGA Mn-Cu powders with a particle size range of 15-53μm have high yield,high bulk density,and good degree of sphericity,thus effectively meet the requirements for that of SLM.The microstructure of SLM printed Mn-Cu alloy is different in the horizontal and the vertical directions,and gradually changes into cellular crystals as the interior of the molten pool extends.Columnar crystals are formed along the welding interface,and the further away from the molten pool,the finer the columnar crystals.Compared with the as-cast,the SLM printed alloy has obvious difference in mechanical properties,with the tensile strength and the proof strength,plastic extension being 611 MPa and 504 MPa respectively,which are much higher than 454 MPa and 172 MPa of the as-cast master alloy.The reason is that the fine grain strengthening effect is obvious,but the existence of microcracks is not good for the plasticity.