等离子体渗硼对硬质合金表面金刚石涂层的影响  

Effect of plasma boriding on diamond coating of cemented carbide surface

作　　者：丁晟 王海龙 马莉[1] 魏秋平[1,2] DING Sheng;WANG Haiong;MA Li;WEI Qiuping(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2024年第3期181-190,共10页Materials Science and Engineering of Powder Metallurgy

基　　金：国家“十四五”重点研究发展计划(2021YFB3701800);国家自然科学基金资助项目(52202056,52274370,52071345,51874370);广东省“十三五”重点研究开发项目(2020B01085001);湖南省高新技术产业科技创新引领计划(2022GK4037,2022GK4047);湖南省自然科学基金资助项目(2023JJ40722);粉末冶金国家重点实验室自主课题(621022230)。

摘　　要：采用热丝化学气相沉积法在等离子体渗硼预处理后的硬质合金表面沉积金刚石涂层,利用扫描电子显微镜、X射线衍射仪、拉曼光谱仪及洛氏硬度计探究预处理过程对金刚石涂层生长质量和结合性能的影响。结果表明:随等离子体渗硼温度升高,基体表面生成的CoWB含量增加,且WC脱碳还原为W。等离子体轰击使基体表面缺陷密度增大,能提高金刚石的形核速率,CoWB钝化层和W过渡层可抑制Co原子扩散,提高金刚石的生长质量。相较于酸碱两步法处理,经过等离子体渗硼处理的硬质合金表面金刚石涂层中石墨相含量明显减少,残余应力随等离子体渗硼温度升高而降低。石墨相含量的减少和残余应力的降低提高了金刚石涂层与硬质合金基体之间的结合性能,1000℃预处理的硬质合金表面金刚石涂层的结合力等级可达HF1水平。After plasma boriding pretreatment,the diamond coating was deposited onto the surface of cemented carbide through hot filament chemical vapor deposition.The effects of pretreatmens on the growth quality and bonding properties of the diamond coating were investigated using scanning electron microscope,X-ray diffractometer,Raman spectrometer,and Rockwell hardness tester.The results indicate that as the plasma boriding temperature increases,CoWB content of the substrates surface increases while WC undergoes decarburization to form W.Plasma bombarding can increase the surface defect density of substrate and improve the nucleation rate of diamond.CoWB passivation layer and W transition layer can inhibit Co atom diffusion and improve the growth quality of diamond.Compared with an acid and alkali two-step method,the graphite phase content of diamond coating on cemented carbide surface after plasma boriding is significantly reduced,and the residual stress decreases with the increase of plasma boriding temperature.The reduction of graphite phase content and residual stress can improve the bonding properties between diamond coating and cemented carbide substrate,after pretreatment at 1000℃,the bonding force of diamond coating on cemented carbide surface can reach the level of HF1.

关 键 词：硬质合金 等离子体刻蚀 气体渗硼 化学气相沉积 金刚石涂层 结合性能 

分 类 号：TB43[一般工业技术]