摘要
目的解决截齿磨损失效问题,研究不同WC颗粒含量对42CrMo截齿激光熔覆Co基/WC复合涂层表面形貌及裂纹率、显微硬度、耐磨/耐腐蚀性能的影响机制。方法通过在42CrMo截齿基体上制备Co基/WC复合涂层,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、显微硬度计、摩擦磨损试验仪及电化学工作站测试不同WC颗粒含量对熔覆层性能的影响。结果Co基/WC复合涂层表面较为平整,当WC颗粒质量分数大于30%时,熔覆层表面开始出现交错裂纹;当WC质量分数为80%时,裂纹率增加35%。Co基/WC复合涂层的显微硬度皆高于42CrMo基体(378HV0.2),随着WC颗粒含量的增加,熔覆层平均显微硬度从448HV0.2提升到890HV0.2。Co基/WC复合涂层的摩擦系数、磨损量均小于42CrMo基体,WC颗粒质量分数增加到80%时,熔覆层平均摩擦系数为0.270,为基体(0.567)的50%,磨损量仅为1.0 mg,相比于42CrMo基体(18.6 mg)降低了约95%,低WC颗粒含量以黏着磨损为主,高WC含量以磨粒磨损为主。熔覆层耐腐蚀性能随WC含量的增加先增大、后减小,WC质量分数为30%时,熔覆层的耐腐蚀性能最好,具有最小的电流密度(1.465×10^(–7)A/cm^(2)),相比基体电流密度(8.031×10^(–6)A/cm^(2))降低了98%。结论WC颗粒含量对Co基/WC复合熔覆层的裂纹敏感性有显著影响,WC颗粒的细晶、弥散及固溶强化使熔覆层的显微硬度、耐磨/耐腐蚀性能得到明显改善。
The work aims to solve the wear failure of the pick,and study the mechanism of how different amount of WC particles effect on the surface morphology,crack rate,microhardness,wear and corrosion resistance of laser cladded Co-base/WC composite coatings on picks made out of 42CrMo.A Co-based/WC composite coating was prepared on 42CrMo substrate.The characteristics of the cladding layer effected by different amount of WC particles were studied by means of X-ray diffraction(XRD),a scanning electron microscopy(SEM),an energy dispersive spectroscopy(EDS),a microhardness tester,a friction and wear tester and an electrochemical workstation.The surface of the laser cladded Co-based/WC composite coating was relatively even.Staggered cracks appeared on the surface of the cladding layer with WC particles content exceeding 30%.With the additive of WC particles content increased,the crack rate increased significantly,and could increase to 35%as the content of WC particles being up to 80%.Three types of cracks were mainly produced in the cladding layer,internal cracks in the cladding layer,cracks in the bonding zone between the cladding layer and the substrate,and cracks in the overlapping zones between multiple layers.When the content of WC particles was low,cracks were mainly appeared as internal cracks and cracks in the bonding zone,and formed independently.Three types of cracks appeared at the same time when high content of WC particles were presented,and the formation of cracks in the bonding zone caused the formation of the other two types of cracks;The microhardness of Co-based/WC composite coating was higher than that of the 42CrMo substrate(378 HV0.2),and the average microhardness of the cladding layer increased from 448HV0.2 to 890HV0.2 with the increase of WC particles content;The average coefficient of friction(Ecof)of Co-based/WC composite coating was less than that of the 42CrMo substrate(0.567).When the content of WC particles was up to 10%,the average coefficient of friction of the cladding layer was 0.411,which
作者
刘东刚
梁国星
郝新辉
贾文婷
杨世清
黄永贵
赵建
吕明
LIU Dong-gang;LIANG Guo-xing;HAO Xin-hui;JIA Wen-ting;YANG Shi-qing;HUANG Yong-gui;ZHAO Jian;LYU Ming(Shanxi Key Laboratory of Precision Machining,College of Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2023年第9期408-419,共12页
Surface Technology
基金
中央引导地方科技发展资金(YDZJSX2021B003)
国家自然科学基金(52105473)
山西省基础研究计划(20210302124050,20210302124121)
山西省创新平台基地建设专项(202104010911007)。
