直接时效处理对锤击复合激光沉积GH4169高温合金组织及性能的影响

Effect of direct aging treatment on microstructure and properties of hammering composite laser deposited GH4169 superalloy

对层间锤击复合激光定向能量沉积(HDED)工艺获得的GH4169高温合金试件进行了直接时效处理。结果表明,经过HDED工艺后试件的组织呈等轴晶和柱状晶交替分布的晶粒形貌,且Laves相含量减少。Laves相的回溶促进了直接时效处理过程中γ″相和δ相的析出,同时细小的等轴晶和试件内部的加工硬化效应在直接时效处理后得以保留。等轴晶的生成对试件产生了细晶强化效应,γ″相的析出为试件提供了沉淀强化作用,因此直接时效处理后试件的力学性能得到了明显提升,其硬度提高到了457.1 HV0.2,横向和纵向抗拉强度分别提高到了1205和1140 MPa。

Direct aging treatment of GH4169 superalloy obtained through hammering directed energy deposition(HDED)process was carried out.The results show that the microstructure of the specimen after HDED process is characterized by alternating distribution of equiaxed and columnar grains,and the content of Laves phase is reduced.The redissolution of the Laves phase promotes the precipitation of theγ"phase and phase during direct aging process,while the small equiaxed grains and the work hardening effect of the specimen are retained after direct aging treatment.The small equiaxed grains produce fine grain strengthening effect,and the precipitation of theγ"phase provides precipitation strengthening effect,by which the mechanical properties of the specimens are significantly improved after direct aging treatment,where the hardness is increased to 457.1 HV0.2,and the transverse and longitudinal tensile strengths are increased to 1205 and 1140 MPa,respectively.