The relation between residual stress, interfacial structure and the joint property in the SiO_2f/SiO₂-Nb joints

In order to achieve a high-quality joint between SiO_2f/SiO₂ and metals, it is necessary to address the poor wettability of SiO_2f/SiO₂ and the high residual stress in SiO_2f/SiO₂-Nb joint. Here, we simultaneously realize good wettability and low residual stress in SiO_2f/SiO₂-Nb joint by combined method of HF etching treatment and Finite Element Analysis (FEA). After etching treatment, the wettability of E-SiO_2f/SiO₂ was improved, and the residual stress in the joint was decreased. In order to better control the quality of joints, efforts were made to understand the relationship between surface structure of E-SiO_2f/SiO₂ and residual stress in joint using FEA. Based on the direction of FEA results, a relationship between residual stress, surface structure and joint property in the brazed joints were investigated by experiments. As well the FEA and the brazing test results both realized the high-quality joint of E-SiO_2f/SiO₂-Nb and the shear strength of the joint reached 61.9 MPa.