H13钢表面激光原位自生TiC颗粒增强复合涂层的微观结构和摩擦磨损性能  

Microstructure and Wear Property of TiC Particle Reinforced Composite Coatings on H13 Steel Surface by Laser in-situ Synthesis

作　　者：姚爽[1] 刘洪喜[1] 张晓伟[1] 李琦[1] 张旭[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093

出　　处：《中国激光》2014年第10期61-67,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(61368003)

摘　　要：利用6kW横流CO2激光器在H13钢基材表面原位合成了以TiC颗粒为增强相的复合熔覆层。借助X射线衍射(XRD)和能谱仪(EDS)分析了涂层的物相组成,结合光学显微镜(OM)和扫描电子显微镜(SEM)观察了涂层的微观组织,运用显微硬度仪和摩擦磨损试验机测试了涂层的硬度和摩擦磨损性能。结果表明,当预置层中Ti与Cr3C2物质的量比为2.44:1时,熔覆层的主要物相为碳化物TiC、Cr7C3和Fe-Cr固溶体。随着预置层中Ti含量的减少,即当预置层中Ti与Cr3C2物质的量比为2:1时,熔覆层中Cr7C3相增多,而当预置层中Ti与Cr3C2物质的量比为2:2.33时,熔覆层中则出现(Cr,Fe)7C3相。SEM和EDS分析显示,TiC增强相随激光功率密度的增大由球状向薄层状转变。当预置层中Ti与Cr3C2物质的量比为2:2.33,激光功率密度为24.38kW·cm-2时,涂层表面宏观质量良好,无气孔裂纹缺陷,涂层截面平均显微硬度达到931.9HV0.2,约为基材的2.21倍,最低磨损失重仅为基材的27.2%。In-situ TiC particle reinforce composite coating is synthesized on H13 steel surface by laser cladding technique.The phase composition,microstructure,friction and wear behavior and Vickers hardness of composite coating are analyzed using X-ray diffraction（XRD）,energy dispersive spectrometer（EDS）,optical microscopy（OM）,scanning electron microscopy（SEM）,wear testing machine and Vickers hardness gage.The results show that the laser cladding composite coating is mainly composed of TiC,Cr7C3 and Fe-Cr phases under the molar ratio of Ti to Cr3C2 of 2.44：1 condition.The content of Cr7C3 phase in coating increases under the molar ratio Ti to Cr3C2 of 2：1 condition,while（Cr,Fe）7C3phase is found under the molar ratio Ti to Cr3C2 of 2：2.33 condition.SEM and EDS analysis indicate that the microstructure of TiC phase gradually changes from ball shape to lamellar with the increasing of laser power density.The cladding coating surface macro morphology is good and no pores or cracks under the molar ratio Ti to Cr3C2 of 2：2.33 and the laser power density 24.38 kW·cm^-2 condition.The highest average Vickers hardness of the laser cladding composite coating is931.9 HV0.2,which is about 2.21 times higher than that of the H13 steel substrate.The lowest wear weight loss of the composite coating is only 27.2%of the substrate.

关 键 词：激光技术 激光熔覆 原位自生 复合涂层 摩擦磨损 显微组织 

分 类 号：O436[机械工程—光学工程]