载荷对金属/织构化三元乙丙密封副摩擦学性能的影响

目的 提高三元乙丙/金属动密封的抗磨性能,揭示织构化橡胶在不同载荷下的磨损机理和损伤演变规律.方法 采用激光打标器在三元乙丙橡胶表面加工规则凹坑阵列,与金属小钢球组成摩擦副,并利用UMT-2摩擦磨损试验机进行摩擦实验,研究不同载荷下织构化三元乙丙橡胶试样的摩擦学特性.通过分析摩擦系数和磨损率等获得实验过程的摩擦学信息,再利用场发射扫描电子显微镜和白光干涉三维表面轮廓仪对磨痕和磨屑进行表面微观分析,并对磨损区域进行三维形貌重组.结果 随着载荷的增加,磨损量都有上升趋势,无织构三元乙丙试件的摩擦系数呈下降趋势,织构化表面摩擦系数先减小、后增大.在载荷为35 N时,织构的摩擦学性能最好,相较于无织构试样,其磨损量下降了33.4％,摩擦系数下降了24.2％,表面粗糙度为245 nm;载荷为80 N时,织构的引入会加剧磨损,表面粗糙度达到了1.12×104 nm.通过观察磨损表面和磨屑形貌得出,在中低载荷下,表面织构可以有效减少腐蚀磨损和粘着磨损;在高载荷下,织构的磨损机理变为磨粒磨损.结论 总体而言,在合适的载荷下,织构化处理可以有效地改善三元乙丙的摩擦性能,但高载荷下织构会增大磨损.

Effect of Load on the Tribological Properties of Metal/Textured EPDM Seal Pair

The purpose of this article is to improve the wear resistance of EPDM or metal dynamic seal pair, reveal the wear mechanism and damage evolution law of textured rubber under different loads. The experimental method is to use a laser marker to process a regular array of pits on the surface of EPDM rubber, which will form a friction pair with small metal steel balls, then the UMT-2 friction and wear testing machine are used to carry out friction tests to study the tribological properties of the textured EPDM samples under different loads. Finally, the tribological information of the test process is obtained by analyzing the friction coefficient and wear rate, then the field emission scanning electron microscope and white light interference three- dimensional surface profiler are used to conduct surface microscopic analysis of wear scars and wear debris, and three-dimensional reconfiguration of the wear area is performed. The test results show that as the load increases, the amount of wear shows an upward trend, the friction coefficient of the non-textured EPDM specimen shows a downward trend, the friction coefficient of the textured surface first decreases and then increases. The texture tribological performance is best when the load is 35 N, and the wear amount is reduced by 33.4% compared with the non-textured sample. The coefficient of friction dropped by 24.2% with surface roughness of 245 nm, when the load is 80 N, the introduction of texture will increase the wear, during which the surface roughness reached 1.12×104 nm. Through the observation of wear surface morphology and wear debris morphology, it is found that the surface texture under medium and low loads can effectively reduce corrosion wear and adhesive wear, but under high load, the wear mechanism of the texture becomes abrasive wear. In general, under appropriate load, the texturing treatment can effectively improve the friction performance of EPDM, but the texture will increase wear under high load.