高频感应熔覆NiTiFe合金涂层摩擦学性能研究

为增强金属材料表面的耐磨性能，采用高频感应熔覆技术，在HT300基底表面制备出NiTiFe合金涂层；利用扫描电子显微镜（SEM）、能谱仪（EDS）、显微硬度计和X射线衍射仪（XRD）对NiTiFe合金涂层的微观组织、元素组成、硬度、相组成和与基底的结合情况进行表征与分析；通过摩擦磨损试验机对涂层的摩擦学性能进行测试，对其摩擦磨损机制进行分析。结果表明：涂层组织致密，无裂缝和空隙，成型质量良好，平均厚度达到0.7 mm，与HT300基底实现了冶金结合；涂层中主要包含Fe2Ti、Fe6.94Ti0.36和Ni3Fe三种相，Fe元素的加入使涂层的晶格发生畸变，硬度提高，平均硬度达到997.36HV，约为HT300基底平均硬度值的5倍。通过摩擦磨损试验发现，试验前期，NiTiFe合金涂层与对摩副之间的摩擦因数较低，维持在0.2左右，对摩副的失效导致摩擦副之间的接触形式发生改变，摩擦因数产生阶跃；随着载荷的增加，涂层上呈现的磨痕宽度在不断增加，对摩副由于磨损造成的材料去除后暴露出的面积也在不断增大。摩擦磨损试验后，NiTiFe合金涂层摩擦表面光滑平整，仅出现了轻微的磨粒磨损，磨损体积远小于对摩副，表现出优良的耐摩擦磨损性能。

Study on Tribological Properties of NiTiFe Alloy Coating by High Frequency Induction Cladding

In order to enhance the wear resistance of metal surface,NiTiFe alloy coating was prepared on the surface of HT300 substrate by high frequency induction cladding technology.Scanning electron microscope (SEM),energy dispersive spectrometer (EDS),microhardness tester and X-ray diffractometer (XRD) were used to characterize and analyze the microstructure,element composition,hardness,phase composition and bonding with substrate of NiTiFe alloy coating.The friction and wear tester was used to test the tribological properties of the coating and analyze its friction and wear mechanism.The results show that the coating has compact structure,no cracks and gaps,good molding quality,and the average thickness reaches 0.7 mm,which realizes metallurgical bonding with HT300 substrate.The coating mainly consists of three phases,including Fe2Ti,Fe6.94Ti0.36 and Ni3Fe.The addition of Fe element causes lattice distortion and increases hardness of the coating,with an average hardness of 997.36HV,which is about 5 times the average hardness value of the HT300 substrate.Through the friction and wear test,it is found that the friction coefficient between NiTiFe alloy coating and the counter-friction pair is low in the early stage of the test,and it is maintained at about 0.2.The failure of the counter-friction pair leads to the change in the contact form between the friction pairs,resulting in a step in the friction coefficient.With the increase of load,the width of wear marks on the coating is also increasing,and the exposed area of the counter-friction pair is also increasing.After the friction and wear test,the friction surface of NiTiFe alloy coating is smooth and flat,and only slight abrasive wear occurs,the wear volume is much smaller than that of the counter-friction pair.It shows excellent friction and wear resistance.