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:研究了氧乙炔火焰喷涂制备的 Al2 O3/ Ti O2 - Ni Cr BSi阶梯热障涂层在水淬热冲击条件下的失效行为。结果表明 ,涂层的抗热冲击能力随梯度成分间隔的减小而增强 ,其失效是由于涂层层间裂纹和层内裂纹共同作用的结果。对于成分梯度化较好的涂层 ,层内裂纹扩展导致网状裂纹是失效的主要原因 ;层间成分间隔大 ,失效则是以层间裂纹的快速扩展而导致涂层整体剥落为主要原因 ;当成分间隔介于以上二者时 ,层内裂纹和层间裂纹共同作用 ,导致涂层以局部脱落或剥落形式失效。
: The failure behavior of Al2 O3 / Ti O2 - Ni Cr BSi stepped thermal barrier coatings prepared by oxyacetylene flame spraying under water quenching and thermal shock conditions was studied. The results show that the thermal shock resistance of the coating increases with the decrease of the spacing of the gradient components, the failure of which is due to the interaction between the cracks in the coating layer and the cracks in the layer. For the coating with better composition gradient, the crack propagation in the layer leads to the main reason that the net crack is the failure; the interlayer spacing is large and the failure is caused by the rapid expansion of the inter-layer crack resulting in the whole coating peeling off; When the component spacing is in between the two, the in-layer crack and the inter-layer crack act together, causing the coating to fail locally in the form of exfoliation or flaking.