热等静压处理对选区激光熔化GH3536微观结构及拉伸性能的影响  

Effects of Hot Isostatic Pressing on Microstructure and Tensile Properties of GH3536 Manufactured Using Selective Laser Melting

作　　者：林可欣 刘秀国[1] 龚宝明[1] 王颖[1] Lin Kexin;Liu Xiuguo;Gong Baoming;Wang Ying(School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学材料科学与工程学院,天津300350

出　　处：《中国激光》2023年第4期43-52,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(51875402)。

摘　　要：利用选区激光熔化技术制备GH3536试样,研究了热等静压处理前、后选区激光熔化GH3536微观结构演变对力学性能各向异性的影响。利用扫描电镜、电子背向散射衍射和拉伸试验等方法对沉积态和热等静压态试样进行了微观组织、晶体织构和力学性能表征分析。研究结果表明,与传统工艺相比沉积态试样形成了超细晶组织且拉伸性能较高。X-Y面中的等轴晶存在〈001〉和〈101〉择优取向;Y-Z面中外延生长的柱状晶结构的〈001〉晶向近似与增材方向平行。受晶粒尺寸及织构强度的影响,相对于纵向试样,横向试样的屈服和抗拉强度更高,但其延展性偏低,在断口中观察到脆性断裂特征及未熔合缺陷。经热等静压处理后,柱状晶粒发生等轴化转变,晶粒取向随机分布,碳化物沿晶界析出,裂纹愈合,但是试样拉伸强度降低,塑性升高,并且各向异性消失。Objective The production of nickel-based high-temperature alloys using selective laser melting(SLM)technology offers significant advantages in terms of material savings,process control,and product performance.However,the use of SLM technology presents several challenges,such as process-induced defects,microsegregation,and anisotropy of the mechanical properties owing to microstructural inhomogeneities.Although several studies on SLM GH3536 have been conducted worldwide,these studies have primarily focused on the effects of process parameters and heat treatment processes on the formability of SLM.Owing to the process characteristics of SLM technology,substantial differences exist in the microstructure and properties of the alloys formed in the additive and laser scanning directions,and these differences have a significant impact on their application.Simultaneously,hot isostatic pressing(HIP)treatment can significantly reduce the defects formed during the SLM process and has a significant impact on the mechanical properties of the material.Therefore,it is necessary to examine the changes in the microstructure and anisotropy of the mechanical properties of SLM-formed alloys before and after HIP.However,there are few systematic studies on the anisotropy of the mechanical properties of SLM-formed GH3536 alloys due to microstructural inhomogeneities,and comparative studies in conjunction with heat treatment are rarely reported in the scientific literature.Using SLM-formed GH3536 specimens as the research object,the microstructure and crystallographic texture characteristics of deposited and HIP specimens are characterized in this study.Additionally,the anisotropy of the mechanical properties of the alloy and its causes are discussed on the basis of the mechanical properties and fracture morphology.Moreover,the effect of HIP on the anisotropic behavior of SLM-formed GH3536 is investigated.This study provides a reference for the practical application of SLM-formed GH3536 alloys.Methods SLM GH3536 specimens were prepared

关 键 词：激光技术 选区激光熔化 GH3536合金 热等静压 微观结构 拉伸性能 

分 类 号：TG113.1[金属学及工艺—物理冶金] TG113.2[金属学及工艺—金属学] TG456.7