论文部分内容阅读
针对激光选区熔化(selective laser melting,SLM)制造K4202合金复杂金属零件在航空航天等领域的应用需求,以K4202合金粉末为材料,研究了该合金的SLM成形工艺、成形态和热处理后的显微组织和力学性能.结果表明,K4202合金SLM成形试样显微组织由树枝晶和等轴晶构成,树枝晶生长方向多与熔池边界近似垂直.固溶+时效处理后,由于再结晶的发生,SLM成形所形成的树枝晶结构完全消失,同时晶界和晶内有金属碳化物析出.时效处理后的组织与SLM成形态相比,变化并不明显,其树枝晶结构保存较完整,晶界处同样有碳化物析出.SLM成形试样的拉伸性能优于传统铸造方法,通过固溶+时效处理和时效处理,试样的屈服强度、抗拉强度均提升显著,但塑性下降明显,其中时效处理后的拉伸强度最高.
Aiming at the application requirements of complex laser melting (SLM) for manufacturing complex metal parts of K4202 alloy in aerospace and other fields, the SLM forming process, microstructure and heat treatment microstructure of K4202 alloy powder were studied. The results show that the microstructure of SLM formed K4202 alloy is composed of dendrites and equiaxed grains and the growth direction of dendrites is almost perpendicular to the boundary of the molten pool.After the solution treatment and aging treatment, , The dendritic structure formed by SLM disappeared completely and the metal carbides precipitated in the grain boundaries and in the grain.The microstructure of the aged after aging treatment was not obvious compared with that of SLM, Carbides also appear in the boundary.The tensile properties of SLM formed specimens are better than that of the traditional casting methods.The yield strength and tensile strength of SLM specimens are obviously improved by aging treatment and aging treatment, Among them, the tensile strength after aging treatment is the highest.