采用大功率连续横流CO2激光对化学复合镀NiAl/纳米Al2O3复合镀层进行激光熔凝处理,并对熔凝层的抗高温氧化性能进行研究。采用X射线衍射仪(XRD)、扫描电镜(SEM)和能谱仪(EDS)等分别对高温氧化前后的表面形貌、物相组织和元素组成进行表征分析。与复合镀层和基体试样相比,激光熔凝后表面抗高温氧化性能明显提高,这一方面与激光熔凝镀层中的金属间化合物NiAl2O4、Ni0.77AlFe0.23在800℃时具有良好的抗高温氧化性有关,另一方面是由于激光熔凝后镀层表面形成了连续致密的氧化膜。 High-power continuous cross-flow CO2 laser was used to laser fusion the electroless NiAl / nano-Al2O3 composite coating, and the high temperature oxidation resistance of the fused layer was studied. The surface morphology, phase structure and elemental composition before and after high temperature oxidation were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) Compared with the composite coating and the matrix specimen, the surface high temperature oxidation resistance after laser fusion is obviously improved. On the one hand, NiAl2O4 and Ni0.77AlFe0.23, which are intermetallic compounds in the laser cladding layer, have good resistance at 800 ℃ On the other hand, due to the high temperature oxidation, the surface of the coating formed by laser fusion forms a continuous and dense oxide film.