不同载荷下激光熔覆钴基合金涂层的摩擦学性能研究  

Tribological Properties of Laser Cladding Co-Based Alloy Coating Under Different Loads

作　　者：徐家乐 谭文胜[1] 胡增荣 王松涛 周建忠[3] Xu Jiale;Tan Wensheng;Hu Zengrong;Wang Songtao;Zhou Jianzhong(Department of Intelligent Equipment,Changzhou College of Information Technology,Changzhou,Jiangsu 213164,China;School of Rail Transportation,Soochow University,Suzhou,Jiangsu 215131,China;School of Mechanical Engineering,Jiangsu University,Zhenjiang,Jiangsu 212013,China)

机构地区：[1]常州信息职业技术学院智能装备学院,江苏常州213164 [2]苏州大学轨道交通学院,江苏苏州215131 [3]江苏大学机械工程学院,江苏镇江212013

出　　处：《激光与光电子学进展》2022年第7期218-225,共8页Laser & Optoelectronics Progress

基　　金：常州市科技计划项目(CJ20210034);江苏省高校自然科学研究面上项目(20KJB460016);江苏省高职院校青年教师企业实践培训资助项目(2020QYSJ129);常州信息职业技术学院校级科研课题资助项目(CXKZ201906Y);常州信息职业技术学院2020年度校级科研平台项目(KYPT202003Z)。

摘　　要：采用激光熔覆技术在GCr15轴承钢基体上制备了钴基合金涂层,对涂层进行了微观组织、显微硬度以及不同载荷下的干摩擦磨损试验研究。结果表明:从熔覆层底部至顶部显微组织分别以平面晶、柱状晶、树枝晶和等轴晶形态分布;由于合金元素的固溶强化、碳化物硬质相的弥散强化与显微组织的细晶强化,涂层的平均显微硬度较GCr15轴承钢提高约1.36倍;随外加载荷的增加,激光熔覆层的平均摩擦系数呈下降趋势,从0.342降至0.261,且波动幅度逐步减小,而磨损率逐渐增大至27.93×10^(-2)mm^(3)·N^(-1)·m^(-1),不同载荷下的涂层呈现不同磨损机制,在150 N的载荷下,涂层以磨粒磨损和轻微氧化磨损为主,随着载荷增加到300 N时,涂层以氧化磨损和粘着磨损为主,当载荷达到450 N时,由于形成了稳定氧化釉质层与加工硬化层,涂层的磨损形式以微切削和强塑性变形为主,磨损表面光滑平整。Laser cladding technology was used to prepare a Co-based alloy coating on a GCr15 bearing steel substrate.The microstructure,microhardness,and dry friction of the coating,and wear experiments were performed using various loads.The results show that the microstructure is in the form of plane,columnar,dendrite,and equiaxed crystals from the bottom to the top of the cladding layer.This is due to the solid solution strengthening of alloy elements,dispersion strengthening of carbide hard phase,and fine grain strengthening of microstructure,and the average microhardness of the coating is approximately 1.36 times higher than that of GCr15 bearing steel.With the increase of external load,the average friction coefficient of the laser cladding layer is increased,the friction coefficient decreases from 0.342 to 0.261,and the fluctuation amplitude decreases gradually,while the wear rate increases to 27.93 × 10^(-2)mm~3·N^(-1)·m^(-1).The wear mechanism of the coating varies with the load.The coating wears primarily due to abrasive wear and minor oxidation wear under a 150 N load.When the load increases to 300 N,the coating primarily wears due to oxidation and adhesive wear.For a 450 N load,the worn form of the coating is primarily due to microcutting and strong plastic deformation,with a smooth and flattening wear surface due to the formation of stable oxide enamel and work hardening layers.

关 键 词：激光技术 激光熔覆 钴基合金涂层 载荷 摩擦磨损 磨损机制 

分 类 号：TG146[一般工业技术—材料科学与工程]