激光熔覆铁基复合熔覆层的裂纹形成机理  

Mechanism of crack formation of Fe⁃based composite layer by laser cladding

作　　者：齐勇田 栗卓新[2] QI Yongtian;LI Zhuoxin(Shanwei Institute of Technology,Shanwei 516600 China;College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]汕尾职业技术学院,广东汕尾516600 [2]北京工业大学材料科学与工程学院,北京100124

出　　处：《兵器材料科学与工程》2024年第3期81-85,共5页Ordnance Material Science and Engineering

基　　金：汕尾职业技术学院资助科研项目(SKQ02021B-017)。

摘　　要：激光熔覆是绿色再制造重点发展的工业技术。用高能密度的二氧化碳(CO_(2))激光束,在工件表面进行激光熔覆改性处理,形成成分和性能完全不同于母材的铁基复合熔覆层。激光熔覆层组织由马氏体α-Fe和细小弥散分布的碳氮化钛Ti(C,N)陶瓷颗粒组成。若激光熔覆工艺不当,会形成纵向或横向裂纹。熔合线附近的气孔和微空洞是复合熔覆层开裂的裂纹源,裂纹最初起裂于熔覆层与母材交界处,裂纹扩展为沿晶或穿晶断裂,属于脆性断裂。Laser cladding is a key industrial technology in green remanufacturing.Using high energy density carbon dioxide(CO_(2))laser beam,the surface of the workpiece was modified by laser cladding,and the composition and properties of the Fe-based composite cladding layer are completely different from that of the base material.The microstructure of the laser cladding layer is composed of martensiticα-Fe and fine dispersed titanium carbonitride Ti(C,N)ceramic particles.If the laser cladding process is not proper,longitudinal or transverse cracks will be formed.The pores and microvoids near the fusion line are the crack sources of the composite cladding layer.The cracks start at the junction of the cladding layer and the base material,and expand to intergranular or transgranular fracture,which belongs to brittle fracture.

关 键 词：激光熔覆 Ti(C N)颗粒 铁基熔覆层 裂纹 

分 类 号：TG174.44[金属学及工艺—金属表面处理]