激光熔覆层中的裂纹一直是一个限制其工业应用的难题。本文首次提出利用声发射技术在线检测熔覆及冷却过程中裂纹的发生和扩展,对三种熔覆粉末的裂纹信号进行分析比较,得出随熔覆层面积厚度及冷却速度的增加,裂纹数增大。多数裂纹产生于熔覆过程,个别在冷却过程。裂纹走向以垂直于激光扫描方向为主,裂纹起源为熔覆层和基体结合带,多数贯穿整个熔覆表面。如能结合热检测,可通过对熔覆材料特定温度下性能改进控制熔覆层裂纹。 Cracks in laser cladding have always been a challenge limiting their industrial application. In this paper, the authors first proposed the use of acoustic emission technology to detect the occurrence and propagation of cracks during the cladding and cooling process. The crack signals of the three kinds of cladding powders were analyzed and compared. The results showed that with the increase of cladding area thickness and cooling rate, Increase. Most cracks originate in the cladding process, some in the cooling process. The direction of the crack is perpendicular to the direction of the laser scanning. The origin of the crack is the cladding layer and the substrate bonding band, most of which run through the entire cladding surface. If combined with thermal testing, cladding cracks can be controlled by performance improvements at a specific temperature of the cladding material.