Effect of Interface Modification of Stearic Acid on Oil Film Lubrication

doi:10.3901/JME.2022.09.182

Abstract

Abstract: The effect of the interface modification by stearic acid has been studied on the oil film lubrication in a slider-on-disc conformal contact under conditions of limited lubricant supply. Using an optical slider bearing test rig, the authors measured the lubrication film thickness versus speed by the base oil PAO10, Silicone oil, and the same base oil with stearic acid (0.1%), calculated the lubrication film thickness under the conditions of continuous double-side ridge thin oil layer and discrete droplet oil supply conditions in theory, and the stearic acid adsorption on the disc surface is characterized. The results showed that the adsorption layer of the stearic acid leads to the low surface energy of the lubrication track, which presents the oil in the form of droplets and promotes the increase of the film thickness. The bounding solid presents a more dense and smooth surface layer due to the adsorption of stearic acid. The discrete oil droplets are crushed into a continuous oil layer through the contact area, and it takes some time for this oil layer to change to discrete droplets, which depends on the properties of the adsorption layer. Moreover, silicone oil can enhance the adsorption of stearic acid, and thus more effective surface modification is obtained and the film thickness increases.

Key words: stearic acid, adsorption film, limited lubricant supply, hydrodynamic lubrication, film thickness

CLC Number:

TH117

HAN Lujuan, GUO Feng, LI Xinming, LI Shuyi. Effect of Interface Modification of Stearic Acid on Oil Film Lubrication[J]. Journal of Mechanical Engineering, 2022, 58(9): 182-189.

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