摘要
目的利用网格阵列润湿(Grid Array Wettability,GAW)表面构筑离散化油池以提高摩擦副表面的自集油作用,改善摩擦副纯滑(η_(SRR)=2)条件下的润滑特性和承载能力。方法利用飞秒激光刻蚀技术制备网格化疏油涂层表面,探究限量供油条件下该表面对润滑状态的影响。利用高黏度聚异丁烯润滑油在纯滑条件下容易产生凹陷油膜的特性,探究GAW表面对油膜形态的调控作用。结果通过对油池形态及膜厚的分析,GAW表面(30~300μm)相较于原始表面具有良好的集油效果,扩展了限量供油条件下乏油边界距离。阵列网格尺寸不同,会对凹陷膜厚和最小膜厚产生不同影响。在限量供油条件下,随着网格尺寸的增大,凹陷膜厚逐渐降低,最小膜厚先增加后降低,当网格横纵间距为200μm时,最小膜厚得到明显提高。其中,小网格尺寸GAW表面集油效果最好,膜厚凹陷特征更加明显。结论GAW表面随网格尺寸增加油膜凹陷逐渐减弱,油膜凹陷由纺锤形转变为椭圆形。实验表明,GAW表面可以有效降低摩擦因数,150mm/s速度下最优尺寸(200μm)GAW表面相较于原始表面摩擦因数降低35.9%。GAW表面增加了摩擦副表面油池的比表面积和油池高度,增加了滚动体与油池的接触,有效提高了润滑效率。
This study aims to utilize a Grid Array Wettability(GAW)surface to construct discrete oil pools,to enhance the oil replenishment,lubrication properties and load-carrying capacity of the friction pair under pure sliding(η_(SRR)=2).Using femtosecond laser etching,a grid-like oleophobic coating surface was prepared to investigate the effect of this grid-like surface on the lubrication state under limited lubricant supply.Using high-viscosity polyisobutylene lubricant under pure sliding conditions,the characteristics of forming oil dimple films were investigated to study the control effect of the GAW surface on oil film morphology.Through analysis of oil pool shape and film thickness,it was found that the GAW surface(30-300μm)exhibited excellent oil replenishment efficiency compared with the original surface and expanded the starvation boundary distance under limited oil supply.Different grid sizes had varying effects on dimple and minimum film thickness.The OS surface,without undergoing chemical modification,had the lowest contact angle and was in the Wenzel wetted state.Oil pools tended to spread on the OS surface,and under the sliding action of the steel ball,they tended to separate from the center line.The contact angles of oil droplets on the AFC and GAW surfaces were relatively similar.Consequently,both surfaces could impede the spreading of oil pools.Under limited oil supply,as the grid size increased,the dimple film thickness gradually decreased,while the minimum film thickness showed a trend of initially increasing and then decreasing.When the grid size was 200μm,as the dimple film thickness decreased,the minimum film thickness significantly increased.Among them,the small grid array wettability surface had the optimal oil replenishment and the dimple film thickness was more pronounced.The smaller the grid width(w)and spacing(d)were,the more pronounced anti-wetting characteristics of the friction pair surface became.As the grid size increased,the slippage area reduced and the degree of oil starvation increased,which could lead to a weakening of the oil film dimple behavior.The increased spacing between discrete oil pools and the decreased height of the oil pools resulted in reduced merging ability of the oil pools at the inlet,resulting in a deteriorated oil supply condition.As the grid size increased,the dimpled oil film formed at the inlet of the contact area gradually transitioned from a spindle-shaped to an elliptical shape.Experiments show that the grid wettability surface can effectively reduce the friction coefficient.At 150 mm/s,the optimal size(200μm)GAW surface can reduce the friction coefficient of 35.9%than the original surface.The GAW surface increases the specific surface area and height of the oil pools on surfaces,increasing the probability of contact between the steel ball and the oil pools.The optimized grid array surface makes the oil distribute orderly,increasing the height of oil pools per unit volume.It also improves the lubricant supply condition at the inlet of the contact area,enhancing lubrication efficiency.As a result,under pure sliding condition,utilizing the optimized grid wettability surface can effectively reduce the accumulation of lubricant due to the thermal effect,take full advantage of surface slip properties,enhance replenishment,facilitate lubricating film formation,and reduce friction losses.
作者
王仕进
刘成龙
郭峰
张建军
朱孔敏
WANG Shijin;LIU Chenglong;GUO Feng;ZHANG Jianjun;ZHU Kongmin(School of Mechanical and Automotive Engineering,Qingdao University of Technology,Shandong Qingdao 266520,China;Zhichuang Future Science and Technology Development Co.,Ltd.,Shandong Liaocheng 252600,China)
出处
《表面技术》
北大核心
2025年第5期93-105,共13页
Surface Technology
基金
国家自然科学基金青年项目(52205201)
国家自然科学基金面上项目(52175173)
山东省自然科学基金青年项目(ZR2022QE027)
山东省智能制造创新创业共同体重点研发计划(gigxjs002)。
关键词
限量供油
网格阵列润湿
纯滑
自集油
油膜凹陷
摩擦因数
润滑效率
limited oil supply
grid array wettability
pure sliding
oil replenishment
oil film dimple
friction coefficient
lubrication efficiency
