Tribological Performance of Rosin Acid Additives in Water Based Lubricants

Lubricants for metalworking applications make extensive use of water-soluble additives to reduce friction and wear. In order to do such task, these additives must form a lubricating film that separates the contact surfaces thus imparting good surface finish to the worked parts. This paper presents a study on the tribological performance of aqueous solutions of rosin acids. Tests were carried out on a pin-on-disk tribometer for a steel-aluminum contact while keeping load, entrainment speed, sliding distance, temperature and concentration of the additive constant to study the lubrication effect of the additive-containing solutions. Chemical analysis of the wear track indicates the in-contact formation of an organic film caused by the additive interaction and aluminium surface. A substantial friction and wear reduction is observed.