WC-10Co-4Cr涂层高温微动磨损特性

Fretting Wear Behavior of WC-10Co-4Cr Coating at High Temperature

为研究WC-10Co-4Cr涂层的高温微动磨损性能和微动磨损机制,采用超音速火焰喷涂技术在Inconel690合金表面制备WC-10Co-4Cr涂层。使用PLINT电液伺服高温微动试验机,在室温25℃至高温300℃大气气氛条件下,选择法向载荷100 N、位移幅值200μm、频率2 Hz、循环次数3×10~4次,进行微动磨损特性试验,通过扫描电子显微镜、双模式轮廓仪和三维共聚焦显微镜等仪器对磨痕进行分析研究。结果表明:涂层组织呈层状叠加的两相分布,致密、孔隙率低,涂层与基体结合紧密,显微硬度为HV810.82,是基体的3.3倍;在法向载荷和位移幅值一定时,随着试验温度的升高WC-10Co-4Cr涂层的摩擦因数增大,且磨损加剧;温度高于250℃条件下,WC-10Co-4Cr涂层发生严重磨损;WC-10Co-4Cr涂层的高温微动磨损机制主要表现为黏着磨损、氧化和剥层的共同作用。

In order to explore the high temperature fretting wear behavior and mechanism of WC-10Co-4Cr coating , high ve- locity oxy-fuel spraying technique was used to prepare the WC-10Co-4Cr coating on the surface of Incone1690 alloy.The fretting wear behavior of WC-10Co-4Cr coating was investigated by PLINT electro-hydraulic servo high temperature fretting tester at the conditions of temperature from 25 ℃ to 300℃ under atmosphere condition,the normal load of 100 N, the dis- placement amplitude of 200 Ixm,the frequency of 2 Hz,and the number of cycles of 3xl04.The wear scar was analyzed by scanning electron microscope, dual mode profilometer and 3D confocal microscopy instrument.The results show that the mi- crostructure of the coating is two phase distribution of lamellar stacking, which is compact and low porosity, and the coating is closely connected with the substrate.The micro-hardness of the coating is HV810. 82,which is 3.3 times of that of the substrate ;the friction coefficient of WC-10Co-4Cr coating is increased with the increasing of temperature under the same normal load and displacement amplitude, and the wear is also increased.When the temperature is higher than 250 ℃, the WC-10Co-4Cr coating is seriously worn.Adhesive wear,oxidation and delamination are the main wear mechanisms of the WC-10Co-4Cr coating at high temperatures.