利用SEM,TEM,EDAX,声发射及磨损试验等方法研究了激光熔覆Al2O3-NiCrAl复合陶瓷层的组织结构、脆性及其干滑动摩擦磨损特性。结果表明：Al2O3激光熔覆层由α-Al2O3柱状晶及柱晶间少量的Ni2Al18O29相组成, 熔覆层硬度达2351～2667Hv0.2,熔覆层的脆性与等离子喷涂层相比有所增大;其耐磨性能为等离子喷涂层的2倍左右,在滑动摩擦条件下熔覆层的磨损机制是脆性剥落和磨料磨损。

The structure, brittleness and dry sliding tribological characteristics of laser-cladded Al2O3 ceramic coatings on W18Cr4V steel have been studied by means of SEM, TEM, EDAX, sound emission and wear tests techniques etc. The results show that the Al2O3 coating cladded by laser consists of columnar grains of α-Al2O3 and a small amount of Ni2Al18O29 among Al2O3 grains. The hardness value of Al2O3 coatings cladded by laser is about 2351～2667Hv0.2. The britlleness of the laser-cladded Al2O3 coatings is increased to some extent than that of a plasma-sprayed Al2O3 coating. In dry sliding wear condition the wear resistance of the Al2O3 coatings is about 2 times that of the plasma-sprayed Al2O3 coating, and the laser-cladded Al2O3 coatings are worn by brittle peeling and abrasive wear.