Effect of joint types on residual stress in ceramic metal joint

By means of finite element numerical simulation, the effect of joint type on residual stress in ceramic/AgCuTi/Kovar/steel joint was investigated.The results show that in the direct butt joint the maximum residual stress is higher than 600 MPa.And halved the thickness of the steel cylinder, the residual stress of the joint can be reduced by 200 MPa compared with that in the direct butt joint.At both cases, the maximum residual stress value occurs on alumina ceramic near the brazing alloy/alumina ceramic interface. The fracture also occurs at this position.The radial stress and circumferential stress have little influence on the joints.And the axial stress and shear stress which have the peak tensile stress in alumina ceramic are the main factors which decrease the properties of the ceramic/metal joint.