激光熔覆涂层增韧改性方法的研究进展  

Research progress on toughening modification of laser clad coating

作　　者：魏新龙 付二广 戴凡昌 班傲林 吴多利 张超[1] Wei Xinlong;Fu Erguang;Dai Fanchang;Ban Aolin;Wu Duoli;Zhang Chao(College of Mechanical Engineering,Yangzhou University,Yangzhou Jiangsu 225127,China)

机构地区：[1]扬州大学机械工程学院,江苏扬州225127

出　　处：《金属热处理》2023年第6期237-248,共12页Heat Treatment of Metals

基　　金：中国博士后科学基金面上项目(2020M671619);江苏省自然科学基金青年基金(BK20200939);扬州市校合作专项(YZ2022182,YZ2021153)。

摘　　要：激光熔覆涂层能够改善金属表面性能,实现表面强化,然而常发现由于涂层韧性降低,涂层表面出现裂纹缺陷问题。概述了激光熔覆涂层由于韧性降低造成裂纹的原因,包括温度梯度差引起的内应力、激光熔覆层中的应力集中以及熔覆层中的微小气孔等。同时归纳了影响激光熔覆层韧性的因素,包括熔覆材料的选择、激光熔覆工艺参数的设定以及熔覆材料的热处理方式等。在此基础上,重点阐述了近年来改善激光熔覆涂层裂纹缺陷问题的进展,并从中寻找增强激光熔覆涂层韧性的方法,包括在熔覆粉体中加入复合陶瓷增强相和稀土元素粉末等改变熔覆粉体组成、在基体与熔覆层之间增加过渡层、改变激光熔覆功率和扫描速率以及光斑直径等工艺参数、对熔覆前基体的预热和熔覆后涂层的热处理、外加超声振动和电磁场以及超声振动与电磁场的耦合等能场辅助等。针对各种增强激光熔覆涂层韧性方法的不足,探讨今后激光熔覆涂层增韧改性方法的研究前景。Laser cladding improves the performance of metal surfaces and achieves surface strengthening.However,it is often found that due to the reduced toughness of the coating,cracks and defects appear on the surface of the coating.The reasons for cracks in laser clad coatings due to reduced toughness are summarized,including internal stress caused by temperature gradient difference,stress concentration in laser clad layers,and small pores in clad layers.At the same time,factors affecting the toughness of laser clad layers are summarized,including the selection of clad materials,the setting of laser cladding process parameters,and the heat treatment methods of cladding materials.On this basis,the progress in improving the crack defects of laser clad coatings in recent years is emphasized,and methods to enhance the toughness of laser clad coatings are studied and searched for,including adding composite ceramic reinforcement phase and rare earth element powder to the cladding powder to change its composition,adding a transition layer between the substrate and the cladding layer,changing laser cladding process parameters such as the laser power,scanning rate,and spot diameter,preheating the substrate before cladding and heat treating the coating after cladding,external ultrasonic vibration and electromagnetic field,as well as coupling of ultrasonic vibration and electromagnetic field and other energy field assistance.Aiming at the shortcomings of various methods for enhancing the toughness of laser clad coatings,the research prospects of future methods for toughening and modifying laser clad coatings are explored.

关 键 词：激光熔覆 涂层韧性 裂纹 增韧方法 

分 类 号：TG174.4[金属学及工艺—金属表面处理]