不同温度低压真空渗氮对新型TiZr基合金微观组织及摩擦学性能的影响  

Effect of Low-pressure Vacuum Nitriding Temperatures on Microstructure andTribological Properties of Novel TiZr-based Alloy

作　　者：吕源远 岳赟 杜志浩 杜三明[1] 倪锋[1] 张永振[1] LYU Yuanyuan;YUE Yun;DU Zhihao;DU Sanming;NI Feng;ZHANG Yongzhen(National United Engineering Laboratory for Advanced Bearing Tribology,Henan University of Science and Technology,Luoyang 471023,Henan,China;School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,Henan,China)

机构地区：[1]河南科技大学高端轴承摩擦学技术与应用国家地方联合工程实验室,河南洛阳471023 [2]河南科技大学材料科学与工程学院,河南洛阳471023

出　　处：《材料导报》2022年第17期163-169,共7页Materials Reports

基　　金：国家自然科学基金(51801054)。

摘　　要：以新型钛锆基合金Ti-47Zr-5Al-3V(以下称47Zr)为研究对象,研究了不同温度(650℃、700℃、750℃、800℃、850℃)低压真空渗氮对合金的摩擦学性能的影响。使用扫描电子显微镜(SEM)和X射线衍射仪(XRD)、显微维氏硬度计及UMT-2摩擦磨损试验机对低压真空渗氮后合金的组织、物相、硬度及摩擦磨损性能进行分析和测试。结果表明,低压真空渗氮后,47Zr合金表面物相以Ti_(2)N、ZrN化合物为主,硬度最高可达710HV_(0.05),表面平均硬度与基体相比提升近285HV_(0.05),渗氮影响层的深度随着温度的升高而增加。不同温度低压真空渗氮47Zr合金中,耐磨性较好的为经750℃和800℃渗氮的样品。相较于原始样品,750℃低压真空渗氮后,样品的平均摩擦系数减小57.14%,磨损率在固定载荷(30 N)下降低29.74%;800℃低压真空渗氮后,样品的平均摩擦系数减小了45.71%,磨损率下降了33.74%。合金的磨损特征表明不同温度低压真空渗氮的47Zr合金在室温干摩擦条件下的磨损机制均为磨粒磨损和粘着磨损。Novel TiZr-based alloy Ti-47Zr-5Al-3V(referred to as 47Zr)was studied to reveal the effect of low-pressure vacuum nitriding at different temperatures(650℃,700℃,750℃,800℃and 850℃)on its tribological properties.Microstructure,phase composition,hardness and tribological properties of 47Zr alloy with low-pressure vacuum nitriding were analyzed and tested by scanning electron microscopy(SEM),X-ray diffraction(XRD),micro-Vickers and UMT-2 multifunctional tribometer.The results indicate that the surface phase composition of nitriding 47Zr alloy is dominated by Ti_(2)N and ZrN compounds,and its hardness is high up to 710HV_(0.05).Compared with the substrate,the average hardness of the surface increases by nearly 285HV_(0.05).The depth of nitrided layer increases with nitriding temperature rising.Compared with the untreated samples,the average coefficient of friction(COF)decreases by 57.14%through low-pressure vacuum nitriding at 750℃,and the wear rate decreases by 29.74%under a normal load of 30 N.Through nitriding at 800℃,the average COF and wear rate decrease by 45.71%and 33.74%,respectively.The wear characteristics show that the wear mechanism of the low-pressure vacuum nitrided 47Zr alloy at different temperature is abrasive wear and adhesive wear under dry sliding condition.

关 键 词：钛锆基合金 渗氮 组织 摩擦磨损 

分 类 号：TB333[一般工业技术—材料科学与工程]