中文摘要：

对爆炸(D-gun)和超音速火焰喷涂(HVOF)MCrAlYX涂层的显微结构、力学性能和抗氧化性能进行研究。结果表明,D-gun涂层呈现片层显微结构,而HVOF涂层呈现均匀结构。同时,在爆炸喷涂过程中发生了元素重新分布以及新相的形成。此外,D-gun涂层的孔隙率明显低于HVOF涂层的。在力学性能方面,2种涂层的显微硬度在同一水平(均在HV 910左右),但由于D-gun涂层的片层显微结构及不同相组成,其纤维硬度的标准偏差明显高于HVOF涂层的。由于涂层颗粒及片层之间存在大量的残余压应力,所以,D-gun涂层的弯曲结合强度明显高于HVOF涂层的。高温氧化实验结果表明,D-gun制备的MCrAlYX涂层的抗氧化性能更优异,因为D-gun涂层更致密,使其表面能够尽早地形成连续致密的氧化保护层,从而进一步抑制氧化并控制氧化膜的厚度较小。

英文摘要：

Microstructure, mechanical property and oxidation resistance of MCrAlYX coatings prepared by detonation gun (D-gun) and HVOF spraying were investigated. Lamellar microstructure and uniform microstructure formed in D-gun sprayed MCrAlYX coating and HVOF sprayed coating, respectively. Element redistribution and formation of new phase took place during the detonation process. Besides, the porosity of D-gun sprayed coating was much lower than that of HVOF sprayed coating. On the mechanical property, the micro-hardnesses of the two coatings were in the same level (~HV 910). However, D-gun sprayed MCrAlYX coating exhibited larger standard deviation of microhardness due to its lamellar microstructure, and exhibited better bend bonding strength owing to the existence of residual compressive stress between the layers and particles. Meanwhile, due to the much more compact microstructure, D-gun sprayed MCrAlYX coating showed superior oxidation resistance to the HVOF sprayed coating. The continuous dense protective layer can form earlier in D-gun sprayed coating and thus suppress further oxidation and control the oxide thickness at a relatively low level.