摘要
利用机械振动辅助激光熔覆技术在高速钢表面制备了WC/Co-Cr梯度复合熔覆层。借助光学显微镜(OM)、X射线衍射(XRD)和HMV-G21ST型显微硬度仪分析了各梯度熔覆层结合界面的微观结构、物相组成和显微硬度。结果表明,熔覆层主要由γ-Co、M23C6(M为Cr、Co、Mo)、W2C、M6C(Co3W3C、Fe3W3C)和少量WC相组成。复合熔覆层的晶粒尺寸实现梯度变化,白色针状、等轴晶弥散分布,提高了熔覆层的力学性能。在水平机械振动的作用下,熔覆层结合界面胞状晶带区较窄,垮界面连续生长的枝状晶提高熔覆层界面连接性。在机械振动作用下,熔覆层硬度呈均匀分布。
WC/Co-Cr gradient composite coatings were fabricated on high speed steel by the combination of laser cladding and mechanical vibration surface modification process.The microstructure,phase composition and microhardnesses of the interface of each gradient cladding layer were examined by OM,XRD and HMV-G21ST microhardness tester.The results show that the cladding layers are mainly composed ofγ-Co and M23C6(M is Cr,Co and Mo),W2C,M6C(Co3W3C,Fe3W3C) and a small amount of WC phases.The grain size of the composite cladding layer is gradient changes,and the white acicular and equiaxed crystals are dispersed,which improves the mechanical properties of the cladding layer.Cellular crystal zones of the cladding layer become narrow and the interface connectivity of the cladding layer improves by the continuous growth of dendritic crystals of the interface under the mechanical vibration condition.The hardness of the cladding layer is uniformly distributed.
作者
吕政
梁国星
吕明
刘东刚
LYU Zheng;LIANG Guoxing;LYU Ming;LIU Donggang(Shanxi Key Laboratory of Precision Machining,College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《热加工工艺》
北大核心
2021年第10期86-89,94,共5页
Hot Working Technology
基金
国家自然科学基金项目(51575375)
山西省自然科学基金项目(201801D121174)
山西省研究生教育创新项目(2019BY051)。
作者简介
吕政(1991-),男,山西忻州人,硕士,主要研究方向:先进制造技术,电话:13303508590:E-mail:lvzheng0019@link.tyut.edu.cn;通讯作者:梁国星(1974-),男,山西忻州人,教授,硕士生导师,博士,主要研究方向:激光增材制造、激光成形及激光焊接技术,E-mail:liangguoxing@tyut.edu.cn。
