偏滤器部件W/Cu功能梯度材料的热应力缓和

Thermal stress reduction in a W/Cu functionally graded material used as a divertor component

W/Cu功能梯度材料是一种有希望用作聚变反应堆面向等离子体部件的侯选材料。为避免材料在使用过程中的热应力破坏,根据偏滤器部件服役的热流工况,在结合导热能力分析的情况下运用有限元软件对W/Cu梯度材料进行了优化设计。结果表明,成分分布指数的增大以及金属W厚度的增加均使表面工作温度提高;当成分分布指数为1.0～1.2时W/Cu梯度材料有最佳的热应力缓和效果。在30MW/m2的表面热流负荷下,与非梯度材料相比,经过优化设计的W/Cu功能梯度材料的等效热应力降低了62.3%,表面工作温度下降了50℃;而与单纯金属W相比,W/Cu梯度材料的表面工作温度较之降低445℃。

 W/Cu functionally graded material (FGM) is a potential candidate for plasma facing material used as a divertor component in a thermonuclear device. The finite element method was used to analyze material failure induced by thermal stresses during operation to optimize the W/Cu FGM design to reduce thermal stresses for typical heat fluxes impinging the divertor. The results showed that the surface working temperature increased with increasing compositional exponent and tungsten layer thickness. Optimal thermal stresse reduction was obtained for the compositional exponent of 1.0～1.2. The von Mises equivalent thermal stresses in a optimal W/Cu FGM design were reduced by 62.3% and the surface working temperature was 50 ℃ lower than for a nonFGM with a heat flux of 30 MW/m2. The W/Cu FGM surface temperature was also a remarkable 445 ℃ below the surface temperature of a monolithic tungsten plasma facing material.