Effects of the inclination angles of DLC end face micro-texture on the tribological properties of dry gas seal rings

Abstract

To improve the tribological performance of the seal rings in the dry gas seal, the elliptical micro-textures with different inclination angles (0°, 45°, 90°, 135°) were processed on the end face of SiC static rings by nanosecond laser. Diamond-like carbon (DLC) films were then deposited on the micro-textured end face. Under dry friction condition, the end-face friction and wear test was conducted to simulate the actual working state of the dry gas seal at start-up phase. The effects of micro-texture inclination angles and DLC phase change on the tribological properties of seal rings were investigated. The possible friction reduction mechanism was analyzed. The results show that compared with the smooth surface, the elliptical micro-texture can effectively improve the tribological properties of DLC films. At the same time, the inclination angle of the elliptical micro-texture has a remarkable influence on the tribological properties. When the micro-texture inclination angle is 90°, the static ring sample has the best friction reduction and wear resistance performance. Compared with the untextured sample, the average friction coefficient is reduced by 46.15%. The wear reduction characteristics of the textured end face are mainly contributed to the capturing effect of the texture on wear particles.