抄録
A tungsten (W) /copper (Cu) graded material has been developed as a new material against high heat flux, for example, plasma, ion beam, electron beam and so on. The combination of these materials is based on high thermal resistance property of W and good thermal conductivity of Cu, and the reduction of thermal stress is performed in graded structure between W and Cu. A sintering and infiltration technique is proposed for fabricating the W/Cu graded composites. On the other hand, an establishment of material design technique is also very important to enhance a heat sink ability of the W/Cu graded composite. In this paper, temperature distribution and thermal stress properties of the W/Cu graded composite are examined, when it is used as a beam target against a high heat flux. Especially, the effect of W/Cu graded structure on the temperature distribution and thermal stress properties is discussed by analyzing a multi-layer structure model. It is shown that a maximum thermal stress is the smallest when the n-value, which is a index number in the equation {W(z)=W1(1-z/t)n, W (z) : W content in thickness z, W1: W content in surface, t : thickness of W/Cu graded zone}, is 0.5.
