摘要
为了研究规则分布的表面形貌对轮轨接触在混合润滑状态下摩擦系数的影响,设计了3种不同的表面纹理:横纹、纵纹、菱形。用确定性模型取代平均流量模型,对膜厚、压力、接触面积比进行了数值计算,总的接触载荷由流体接触区和固体接触区分别分担,总的摩擦力等于流体区的摩擦力和固体接触区摩擦力之和。根据设计的3种表面纹理,用YAG激光对车轮钢试样表面进行激光毛化处理,获得这3种表面纹理,在RSW-2摩擦磨损试验机上进行油介质条件下的混合润滑摩擦学实验,模拟轮轨间有油污时的工况,测量了该条件下各种表面纹理下的摩擦系数,并与未作激光毛化处理的表面进行对比。理论和实验结果显示,在油介质混合润滑条件下,有激光表面纹理的摩擦系数远大于未作激光毛化处理的试样表面的摩擦系数。3种激光表面纹理中,菱形纹理的摩擦系数大于纵纹和横纹的摩擦系数,纵纹的摩擦系数比横纹略大。因此,在油污条件下使用激光毛化的菱形纹理表面能较显著地提高轮轨间的摩擦系数。
To investigate the influences of regular patterns on friction coefficients of wheel-rail contact under mixed lubrication, longitudinal, transverse and rhombus patterns are designed. The film thickness, pressure and contact area ratio are calculated by using deterministic model instead of average flow model. Based on the load- sharing concept, the hydrodynamic film and asperities both contribute to carrying the total load. Therefore the friction force is composed of hydrodynamic friction force and asperity friction force. According to the designed patterns, the surfaces of wheel discs are textured by YAG laser. The friction coefficients are tested on a RSW-2 type wear testing machine and the results are compared with that of the grinded without laser textured. It is shown theoretically and experimentally that the friction coefficient of rhombus pattern is higher than that of longitudinal and transverse patterns. And the friction coefficient of longitudinal pattern is slightly higher than that of transverse pattern. Therefore, laser texturing of the textured surface with rhombus distribution can increase the friction coefficient obviously between wheel and rail under oil-contamination condition.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2015年第6期106-113,共8页
Chinese Journal of Lasers
基金
国家自然科学基金(51275510)
国家973发展计划(2011CB711103)
关键词
激光技术
摩擦系数
激光毛化
混合润滑
laser technique
friction coefficient
laser texturing
mixed lubrication
