TC4钛合金表面等离子喷涂Ni基WC涂层的组织及性能分析

Microstructure and Performance of Ni-based WC Coatings Prepared by Plasma Spraying on TC4 Titanium Alloy Surface

采用等离子喷涂技术在TC4钛合金表面制备了Ni基WC耐磨涂层,利用扫描电镜、能谱仪、显微硬度仪、摩擦磨损试验机、X射线应力仪等研究了涂层的微观组织、成分、硬度、磨损量、磨损机制及残余应力特性等。结果表明:涂层呈现典型的层状结构,与基体结合良好,面层孔隙率为4.7%。显微硬度由表及里呈梯度变化,在798～990HV0.3之间波动,同载荷下基体体积磨损量是涂层的8.9倍,基体磨损机制主要为磨粒磨损和黏着磨损,涂层磨损机制以磨粒磨损为主。涂层表面无裂纹存在,分布着压应力状态的残余应力。

Ni-based WC wear-resisting coatings were prepared on the surface of TC4 titanium alloy by plas- ma spraying technology. The coatings＇ properties such as microstructure, component, microhardness, abra- sion loss, wear mechanism and residual stress were investigated by scanning electron microscope （SEM）, ener- gy dispersive spectrometer （EDS）, microhardness tester, friction wear test equipment, X-ray residual stress measurement tester, and so on. The results demonstrate that the coatings show typical layer structure and bond well with the TC4 substrate, the porosity of Niq-30%WC coating is 4.7%. The microhardness presents gradient change from the coating to the substrate, which fluctuates in 798;990 HV0.3. The wear volume of the substrate is 8.9 times of coating under the same load. The wear mechanism of the substrate are mainly ab- rasion wear and adhesive wear, while the coating is mainly abrasion wear. The coating surface has no cracks and its residual stress is compressive stress.