C18150/316L扩散连接界面微观组织及性能研究

Research on Microstructure and Properties of C18150/316L Diffusion Interface

采用真空扩散连接技术制备了C18150/316L复合板,通过室温剪切试验对其结合性能进行了测试。采用光学显微镜观察复合板结合界面附近的显微组织,并利用扫描电镜(配X射线能谱仪)分析了断口形貌及界面附近Cu、Fe、Cr、Ni等元素的分布情况。结果表明,C18150/316L界面附近组织致密,并且形成了大量Cu、Ni固溶体,不存在裂纹、孔洞、杂质等微观组织缺陷。复合板界面剪切强度约为228 MPa。剪切断裂发生在靠近C18150母材一侧,并且断裂前发生了10%~12%的应变,表明连接界面的强度高于C18150母材。在室温、200℃、300℃下,向密闭空腔结构内通入压力为1 MPa的高纯氦气进行检漏,测得的实际漏率均为1.1×10^(-10)Pa·m^(3)/s,表明连接界面具有良好的气密性,满足核聚变装置壳体加工制造对材料漏率的相关要求(小于1.5×10^(-8)Pa·m^(3)/s)。

C18150/316L clad plates were prepared by vacuum diffusion bonding technique and the bonding properties were tested by shear test at room temperature.The microstructure of the clad plate near the interface was observed by optical microscopy.The fracture morphology and the distribution of Cu,Fe,Cr and Ni near the interface were analyzed by scanning electron microscopy(SEM).The experimental results show that the microstructure near the C18150/316L interface is dense,a large number of Cu and Ni solid solutions are formed and there are no cracks,holes,impurities and other microstructure defects.The interfacial shear strength of the clad plate is about 228 MPa.The shear fracture occurs near the C18150 base metal and 10%-12%strain occurs before the fracture,indicating that the strength of the interface is higher than that of the C18150 base metal.At room temperature,200℃and 300℃,high purity helium gas with a pressure of 1 MPa is injected into the closed cavity structure for leak detection.The actual leakage rates are all 1.1×10^(-10)Pa·m^(3)/s,indicating that the interface has good air tightness.It meets the relevant requirements of material leakage rate(less than 1.5×10^(-8)Pa·m^(3)/s)for the shell manufacturing of nuclear fusion device.