本文研究了低压等离子喷涂的Ni_3Al-Y_2O_3扩散障层对外层涂层与基体间元素互扩散的阻碍作用,发现阻碍扩散的作用与扩散障层中氧化物含量有关。当Y_2O_3含量为8wt-%时,扩散障对元素互扩散没有明显的阻碍作用;当Y_2O_3含量为30wt%时,对Al,Co和Cr等元素的扩散有明显的阻碍作用。并且,阻碍作用随元素不同而不同。 In this paper, we studied the barrier effect of low pressure plasma sprayed Ni_3Al-Y_2O_3 diffusion barrier on the inter-elemental diffusion between the outer coating and the matrix, and found that the effect of inhibiting the diffusion is related to the oxide content in the diffusion barrier. When the content of Y_2O_3 is 8 wt-%, the diffusion barrier has no obvious hindrance to the interdiffusion of elements. When Y_2O_3 content is 30 wt%, the diffusion barrier of Al, Co and Cr are obviously inhibited. And, the hindrance will vary from element to element.