在双层辉光离子渗金属中空位浓度梯度对扩散的影响

Effect of Concentration Gradient of Vacancies on Diffusion in Double Glow Plasma Surface Alloying

在双层辉光离子渗金属中 ,由于高能量的离子轰击 ,在金属表面以下一定深度产生高的空位浓度、位错密度和空位浓度梯度 .根据空位机制 ,从扩散流量导出钼的扩散系数的表达式 .同时分析了高空位浓度、高空位浓度梯度对金属原子扩散的影响 ,指出这些是 DGPSA的扩散系数远高于普通渗金属方法的主要原因 .

In double glow plasma surface alloying(DGPSA), high vacancy concentration, high dislocation density and high concentration gradient of vacancies are produced at a definite depth under surface by ion bombardment. This paper derives the expression of the diffusivity of molybdenum from diffusion flow. Based on vacancy mechanism, it also analyzes the effect of the high vacancy concentration and high concentration gradient of vacancies on diffusion of metal atoms. It points out that these are the main reason why the penetrating velocity of DGPSA is higher than that of conventional diffusion processes.