采用Nd:YAG固体脉冲激光器,在镍基高温合金上激光熔敷镍基自熔合金,对激光多次辐照条件下熔敷层的开裂问题进行了探索性研究。试验结果表明：脉冲激光多次辐照,对熔敷层的组织及硬度影响不大；激光辐照次数的增多,促进了熔敷层裂纹萌生,其裂纹形态为沿晶高温液化裂纹；对基材热输入的增多,促进了基材再热裂纹的萌生。

The influence of irradiation manner of a YAG-pulsed laser on the microstructure and cracking behavior of claddings was characterized. It follows that the microstructures of the cladding may not show a visible change after multi-irradiation with the YAG-pulsed laser beam,however,multi-irradiation do promote the appearance of cracking on claddings. The tendency of cracking of the same cladding may increase with the increase of the number of irradiation. The formed cracks show a feature of along grain boundary like hot cracking. Additionally,more heat input during the process may increase the tendency of initiation of the re-heat cracking in the substrate alloy as well.