采用电火花沉积分别制备了碳化铬基金属陶瓷单涂层和碳化铬基金属陶瓷/Ni复合涂层。采用X射线衍射仪(XRD)、扫描电镜(SEM)、显微硬度计和摩擦磨损试验机对比研究了单涂层和复合涂层的物相、微观组织结构、显微硬度和摩擦磨损性能。结果表明,两种涂层组织结构致密,与基体呈良好的冶金结合,并在涂层内形成了纳米晶的微观组织。复合涂层中FeCr0.29Ni0.16C0.06韧性相含量增加,在涂层界面处存在过渡层Ni,并以塑性变形的方式释放了更多沉积时产生的热应力,因而涂层裂纹明显减少。复合涂层的峰值硬度(11.86 GPa)虽略低于单涂层,但该涂层具有最小的摩擦系数(0.2462),1 h磨损量仅为单涂层的1/3,因此表现出更好的耐磨性能,其主要磨损机制为磨粒磨损和疲劳磨损。
The chromium carbide based metal-ceramic monolithic coating and chromium carbide based metal-ceramic/Ni composite coating were prepared by electro-spark deposition. The phase composition, microstructure, microhardness and tribological properties of the monolithic and composite coatings were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),microhardness test, friction and wear test, respectively. The results indicate that the two kinds of coatings are dense, meta llurgically bonded to the substrate and have a nanocrystalline microstructure. In the composite coating, the content of FeCr0.29Ni0.16C0.06 plastic phase increases and the Ni transition layer exists at the interface, which can release the thermal stress via plastic deformation;therefore the cracks decrease in number significantly. Meanwhile, the maximum microhardness of the composite coating(11.86 GPa) is slightly lower than that of the monolithic, but the composite coating displays the minimum friction coefficient(0.2462), and its wear ma ss of 1 h is only 1/3 of that of the monolithic;therefore it displays better tribological properties and the main wear mechanisms are abrasive and fatigue wear.
Rare Metal Materials and Engineering
chromium carbide based metal-ceramic coatings
张怡,女,1993年生,硕士,中南大学,湖南长沙410083,E-mail:firstname.lastname@example.org;Corresponding author:Chen Zhiguo,Ph.D.,Professor,Hunan University of Humanities,Science and Technology,Loudi 417000,P.R.China,Tel:0086-738-8235517,E-mail:email@example.com.