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采用冷喷涂制备了Ni-Al2O3复合涂层,并通过真空热处理改善了Ni-Al2O3复合涂层的组织与性能。结果表明,后热处理可使涂层与基体发生冶金结合,同时热处理态涂层的孔洞缩小、层间裂纹间隙有闭合趋势,涂层更致密。但热处理对Al2O3颗粒的尺寸、分布及形貌几乎没有影响。同时热处理态涂层断口表现出韧性断裂特征,基体颗粒之间以及基体与增强体之间的结合增强。热处理后涂层硬度降低为(98.2±19.2)HV0.2,涂层韧性得到提高。
Ni-Al2O3 composite coating was prepared by cold spraying, and the microstructure and properties of Ni-Al2O3 composite coating were improved by vacuum heat treatment. The results show that the post-heat treatment can make the coating metallurgically bond with the substrate, meanwhile the pores of the heat-treated coating shrink, the gap between the layers cracks and the coating is denser. However, the heat treatment has little effect on the size, distribution and morphology of Al2O3 particles. At the same time, the fracture of the heat-treated coating showed ductile fracture characteristics, and the bond between the matrix particles and between the matrix and the reinforcement was enhanced. After the heat treatment, the hardness of the coating decreased to (98.2 ± 19.2) HV0.2, the coating toughness was improved.