Estimation on interfacial mechanical strength in the W/Cu bonded structure for high heat flux component

Cyclic thermal tests and thermoelastic-plastic structure analyses have been performed on tungsten-copper duplex structures to investigate mechanical behavior on residual stress after cyclic heat loads of 14 MW/m²-2 sec. Good agreement was obtained for the residual stresses on both the tungsten top surface and side surfaces. Both the radial and hoop residual stress components σ_Kσ _θ of the tungsten top surface decreased with the increase of the number of heat load cycles. Axial stress component σ_x on the tungsten side surface was also reduced with the increase of the number of heat cycles. Relaxation of the residual stress occurred by the elastic-plastic deformation of copper heat sink. It was found that cyclic thermal loads lead to the reduction of residual stress in the tungsten-copper duplex structure and it is favorable in view of the structural integrity of bonded structure