摘要
通过激光熔覆方法在YG8硬质合金表面制备WC/TiC/Co涂层,借助扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)观察组织结构并分析其物相组成,并对其显微组织、硬度分布和摩擦磨损性能进行了观察和测量。结果显示:涂层表面平整,与基体结合紧密,截面形貌良好没有明显缺陷。表层和两侧存在未熔的WC颗粒,熔覆层中WC颗粒消失,新产生的组织分布均匀。受激光影响,热影响区中的WC晶粒发生重结晶和再结晶。熔覆层主要物相为WC、W_(2)C、(Ti,W)C_(1-x)、M_(6)C(Co_(4)W_(2)C、Co_(3)W_(3)C)等,这些硬质相和碳化物的生成及弥散分布提高了熔覆层性能。通过测量,熔覆层硬度分布在1700~1800 HV0.5,最高为1783 HV0.5,高于YG8硬质合金,而热影响区和基体的硬度则稍有下降;耐磨性也有大幅提高,熔覆层体积磨损量比YG8合金减少90.67%,平均摩擦因数为0.293,主要磨损形式为磨粒磨损。
WC/TiC/Co coating on YG8 cemented carbide surface was prepared by laser cladding,and the microstructure and the phase composition were analyzed by means of scanning electron microscope(SEM),energy disperse spectroscopy(EDS)and X-ray diffraction(XRD),respectively.In addition,microhardness,hardness distribution and wear resistance were measured or tested.The results show that the coating surface is flat and bonded to the matrix tightly,the cross section morphology is fine without obvious defects.WC particles can be find in surface layer and edges while disappear in clad layer,and new homogeneous microstructure is observed in clad layer.In heat affected zone,WC grains take place recrystallization and gather because of heat effect of laser.The phases in clad layer are mainly composed of WC,W_(2)C,(Ti,W)C_(1-x),M_(6)C(Co_(4)W_(2)C,Co_(3)W_(3)C),etc,which result in dispersion strengthening,greatly enhance the performance of the coating.After detection,the microhardness of the clad layer distributes in the range of 1700-1800 HV0.5,and the maximum reaches 1783 HV0.5,which is obviously higher than the common YG8 cemented carbide,while the microhardness of heat affected zone and matrix is slightly decreased.Wear resistance of the clad layer is heightened effectively,compared with the YG8 cemented carbide,wear volume is reduced by 90.67%,average friction coeffiaiont is 0.293,and the abrasive wear is major wear mechanism.
作者
梁伟印
梁国星
董黎君
刘东刚
王时英
Liang Weiyin;Liang Guoxing;Dong Lijun;Liu Donggang;Wang Shiying(College Mechanical and Vehicle Engineering,Taiyuan University of Technology,Taiyuan Shanxi 030024,China;Shanxi Key Laboratory of Precision Machining,Taiyuan Shanxi 030024,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2021年第12期168-174,共7页
Heat Treatment of Metals
基金
山西省重点研发计划(201903D121068)
山西省自然科学基金(201801D121176)。
