MHC/GH4099热等静压扩散焊接头组织演化及断裂机制  

Microstructure evolution and fracture mechanism of diffusion bonded MHC/GH4099 joint by hot isostatic pressing

作　　者：黄赞军[1,2] 张龙戈 车洪艳 王铁军[1,2] 董浩 曹睿[3] HUANG Zanjun;ZHANG Longge;CHE Hongyan;WANG Tiejun;DONG Hao;CAO Rui(Advanced Technology&Materials Limited Company,Beijing 100081,China;Engineering and Technology Research Center of Hot Isostatic Pressing,Baoding 072750,China;State Key Laboratory of Advanced Process‐ing and Recycling of Non-ferrous Metal,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]安泰科技股份有限公司,北京100081 [2]河北省热等静压技术创新中心,河北保定072750 [3]兰州理工大学有色金属先进加工与再利用省部共建国家重点实验室,甘肃兰州730050

出　　处：《粉末冶金工业》2024年第1期60-69,共10页Powder Metallurgy Industry

摘　　要：实验研究了不同中间层(Ni-Cr-Si-B、Ag-Cu-Ti、Ti-Cr-Ni、Nb-Ni)对MHC与GH4099合金热等静压扩散焊工艺(HIP-DB)下接头力学性能的影响。在热等静压工艺为1150℃/130 MPa/180 min时,采用Nb-Ni中间层获得了可靠的MHC/GH4099焊接接头。采用Nb-Ni中间层的接头抗拉/抗剪强度达到84/41 MPa,高于采用Ni-Cr-Si-B、Ag-Cu-Ti和Ti-Cr-Ni中间层的连接强度。其扩散诱导反应层为Mo-Nb固溶体、Ni_(8)Nb、Ni_(3)Nb和Ni_(6)Nb_(7),对其强度和厚度进行了测定,以建立界面微观结构与接头性能的相关性。研究发现,析出相Ni3Nb强度高、塑性好,对接头高温性能有益,裂纹从Mo-Nb固溶体处萌生,沿晶扩展至中间扩散层。To form a satisfactory bonding between Molybdenum-Hafnium-Carbon(MHC)and GH4099 alloy,in-terlayers are used to alleviate the huge property difference,such as thermal expansion coefficient of the two materi-als.This study focused on interlayers and different layer composition to investigate the bonding microstructure and fracture mechanism.Direct diffusion bonding between MHC and GH4099 is difficult due to the low diffusion rate and brittle intermetallic compound formed.Hot isostatic pressing diffusion bonding technology(HIP-DB)was ad-opted as the major process in this study by inserting layers between them.The effect of different interlayers(NiCr-Si-B,Ag-Cu-Ti,Ti-Cr-Ni,Nb-Ni)on the mechanical performance of welded joint between MHC and GH4099 alloys by(HIP-DB)was investigated.Optical Microscope(OM)and Field Emission Scanning Electronic Micro-scope(FE-SEM)with energy dispersive spectroscopy(EDS)analysis were applied to analysis the microstructures of the bond,fracture morphology and element distribution.Ni-Cr-B-Si interlayer tends to form brittle Mo-Ni inter-metallic phase that is regarded as the main cause of brittle fracture morphology observed.Bond strength with NiCr-B-Si interlayer is very poor.Ag-Cu-Ti interlayer can both react with MHC side and GH4099 side,which lend bond shear strength of 27 MPa.Microstructure observation shows that there are Kirkendall pores reside in the frac-ture surface which is responsible for the low bond strength.Ti-Cr-Ni interlayer does not form an effective metallur gical bonding,which is attributed to the intrinsic weak strength of TiCrNi material and low HIP-DB process tem-perature.Nb-Ti interlayer forms good metallurgical bonding between MHC and GH4099.Effective diffusion has taken place in MHC/NbTi bond although some pores exist in this area,due to the significant difference of diffusion rate of Mo and Nb.The diffusion-induced reaction layers are determined to be the Mo-Nb solid solution,Ni_(8)Nb,Ni_(3)Nb and Ni_(6)Nb_(7).Their strength and thickness are measured in order to es

关 键 词：热等静压 GH4099合金 MHC合金 断裂机制 扩散连接 

分 类 号：TG453.9[金属学及工艺—焊接]