Design of tungsten/copper graded composite for high heat flux components

A thermal stress analysis system has been developed which enables the accurate analysis of multilayer composites such as functionally graded materials. The method is based on a strain suppression technique and Timoshenko's beam theory. In this paper a design method for a tungsten/copper graded composite for high heat flux components is proposed. The thermal stress properties of the graded composites have been analysed using the thermal stress analysis system by paying attention to the reduction of thermal stress. A tungsten/copper graded composite for a high heat flux sink has been chosen for the residual stress analyses in the case of uniform heating during fabrication and tungsten surface heating with temperature differences during operation. It has been verified that an approach based on an equivalent heat transfer coefficient lambda(eq) = constant is useful for optimizing the tungsten/copper graded profile. Also, the specimen geometry of a tungsten/copper graded composite for an electron beam irradiation test has been determined by the design method. The optimized tungsten/copper graded composite has been fabricated using a new sintering and infiltration technique. The first phase in the fabrication process is to make sintered tungsten with graded pores; in the second phase, molten copper is infiltrated into the graded pores. Finally, the electron beam irradiation test has shown that the tungsten/copper graded composite can successfully endure a stationary heat flux of up to 15 MW m(-2).