等离子堆焊Cr3C2／钴基合金涂层的组织结构与耐磨性能研究  

Microstructure and Wear Resistance of Cr_3C_2/Cobalt-Based Alloy Coating Deposited by Plasma Transferred Arc Surfacing

作　　者：高胡鹤 丁婷婷[3] 马淑谨 王萍[3] 侯清宇[3,4] 黄贞益[3] 

机构地区：[1]合肥工业大学机械与汽车工程学院,安徽合肥230009 [2]泰尔重工股份有限公司,安徽马鞍山243000 [3]安徽工业大学金属材料与加工安徽省重点实验室,安徽马鞍山243000 [4]合肥工业大学,安徽合肥230009

出　　处：《稀有金属》2016年第11期1119-1125,共7页Chinese Journal of Rare Metals

基　　金：安徽省自然科学基金项目(1508085ME95);中国博士后科学基金项目(2014M551796);中央高校基本科研业务费专项资金项目(20136h2x0063)资助

摘　　要：采用光学显微镜(OM)、X射线衍射仪(XRD)、扫描电镜(SEM)、能谱分析(EDS)以及磨粒磨损实验机研究了20%Cr_3C_2对等离子堆焊钴基合金涂层组织结构和耐磨性能的影响,并采用X射线衍射的Rietveld精修方法研究了添加Cr_3C_2前后钴基合金涂层的相组成及其相对含量变化。结果表明,等离子堆焊钴基合金涂层主要由初晶α(Co)固溶体及其间的(α(Co)+M_7C_3)共晶组织构成,具有亚共晶的组织特征,M_7C_3呈网状分布在α(Co)固溶体上。20%Cr_3C_2(质量分数)的加入使涂层的结晶方式转变为具有离异共晶特征的过共晶形式,条状或块状M_7C_3、未熔的大块状Cr_3C_2以及沉淀析出的小块状Cr_3C_2分布在α(Co)固溶体上。20%Cr_3C_2的加入细化了钴基合金涂层的组织,提高了M_7C_3的相对含量,而α(Co)的相对含量则有所降低。等离子堆焊钴基合金涂层的磨粒磨损机制主要为脆性剥落和犁削,含20%Cr_3C_2的钴基合金涂层的耐磨性能是未添加Cr_3C_2钴基合金涂层的约1.8倍,其磨粒磨损机制以轻微犁削为主。The effects of 20 % Cr3C2 addition on microstructure and wear resistance of a cobalt-based alloy （Cr3C2-free） coating deposited by plasma transferred are （PTA） surfacing were investigated by optical microscopy （OM）, X-ray diffraction （XRD）, scanning electron microscopy （SEM） with energy dispersive spectroscopy （EDS） attachment and abrasive wear test. More detailed information about phase constitutions and their relative contents before and after Cr3C2 addition was studied using XRD Rietveld refinement method. The results showed that the Cr3C2-free coating consisted of primary α（Co） solid solution and eutectic （α（Co） ＋ M7C3 ） , indicating a hypoeutectic microstructure existing in the coating where M7 C3 distributed in α（Co） solid solution by a network. Adding 20% Cr3C2 （Cr3C2-added） （mass fraction） led to the solidification style changing from hypoeutectic microstructure in the Cr3C2-free coating into hypereatectic microstructure with characteristic of divorced eutectic in the Cr3 C2-added coating where bar or block MTC3 , undissolved big block Cr3 C2, and precipitated small spherical Cr3 C2 distributed inα（Co） solid solution. Adding 20% Cr3C2 fined the microstructure, increased the relative contents of M7C3 phase, and decreased the relative contents of α（Co） of cobalt-based alloy coating. Abrasive wear mechanism of the Cr3C2-free coating was dominated by brittle spalling and ploughing. The wear resistance of the Cr3C2-added cobalt-based alloy coating was about 1.8 times that of the Cr3C2-free cobalt-based alloy coating. Abrasive wear mechanism of the Cr3C2-added coating was dominated by mainly slight ploughing.

关 键 词：钴基合金 CR3C2 RIETVELD精修 组织结构 耐磨性能 

分 类 号：TG146.16[一般工业技术—材料科学与工程] TG455[金属学及工艺—金属材料]