激光熔覆高耐磨无裂纹双层Fe基非晶复合涂层

Highly Wear-resistant and Crack-free Double-layer Fe-based Amorphous Composite Coatings by Laser Cladding

在40Cr钢表面采用SAM2X5非晶合金粉末分别进行了单层和不同扫描速度的双层激光熔覆,制备了无裂纹Fe基非晶复合涂层。分析了双层熔覆工艺对Fe基非晶复合涂层的微观组织、元素分布、硬度及耐磨性的影响。结果表明,双层熔覆Fe基非晶合金复合涂层能够提升涂层的硬度和耐磨性。另外,随第2层激光扫描速度增加,基体对涂层的成分稀释作用减小且涂层的硬度和耐磨性随之提升。第2层激光扫描速度为1 m/min时涂层硬度最高,平均硬度(HV_(0.1))达到852,约为基体的3倍。涂层耐磨性远高于基体,在第2层扫描速度为1 m/min时涂层耐磨性达到最优,磨损体积仅为基体的28%。

The crack-free Fe-based amorphous composite coatings were prepared by single-layer and double-layer laser cladding with different scanning rates on the surface of 40Cr steel using SAM2X5 amorphous alloy powder.Effects of double-layer cladding process on microstructure,element distribution,hardness and wear resistance of Febased amorphous composite coatings were analyzed.The results indicate that the double-layer cladding of Fe-based amorphous alloy composite coating can enhance the hardness and wear resistance of the coating.In addition,as the laser scanning rate of the second layer increases,the composition dilution of the coating by the substrate is decreased,and the hardness as well as wear resistance of the coating are increased.The hardness of coating reaches the highest at the second laser scanning rate of 1 m/min,with an average hardness of 852 HV_(0.1),which is about three times of the substrate.The wear resistance of the coating is much higher than that of the substrate,reaching the optimal at the sec⁃ond scanning rate of 1 m/min,where the wear volume is 28%of that of the substrate.