研究了45#钢表面激光熔覆纳米Al2O3复合陶瓷涂层的微观组织结构、显微硬度和磨损特性.结果表明,激光熔覆层由α-Al2O3和TiO2以及Al2O3纳米颗粒组成,在激光的作用下,消除了原来等离子喷涂层的片层状组织;纳米颗粒仍然保持纳米尺度,填充在涂层的大颗粒之间,起着桥连的作用;同时涂层气孔率的降低使涂层致密化程度得以提高,纳米Al₂O₃涂层的显微硬度较高,且其耐磨性能明显优于等离子Al2O3+13%TiO2喷涂层.

The microstructure, microhardness and characteristics of wear of laser-cladding n-Al₂O₃ composite ceramic coatings on 45 steel are studied. The results show that lamellas structure characteristics of plasma-sprayed coating have been eliminated after laser-cladding and n-Al₂O₃ composite ceramic coating consists of α-Al₂O₃，TiO₂ and nano Al₂O₃ particles. A great deal of nano-Al₂O₃ particles have been found because laser heats and cools at the very high speed, and they are filled between the particles of composite ceramic coating and plays an important role in the performance of ceramic coating. The ceramic coating displays rather dense, that is, it possesses a low porosity. Laser-cladding nano- Al 2O 3 ceramic coating has the higher hardness and obviously superior wear resistance than plasma spraying Al₂O₃+13%TiO2 coating.