Computer Simulations of Alkali Phosphate/Borate Lubricant at Sliding Interface in Metal Forming

Inorganic glasses such as alkali metal phosphate or borate have been proven to be the most effective lubricants for high temperature lubrication in hot metal forming. When the lubricants are introduced into a metal-metal contact, multiple physical/chemical phenomena such as adsorption, tribochemical reactions and tribofilm formation occur under the effects of heavy loads, sliding motion, and high temperature. These processes not only transform lubricant structures but also modify profoundly the contacting interface and induce surface complexity, which eventually affect the overall lubricant effectiveness. In recent years, experimental measurements on friction, wear, and tribofilms obtained from alkali phosphate/borate lubricated systems have been reported, however little research has been done to understand the functioning mechanisms of alkali phosphate/borate and steel surface interactions and chemical reactions, and the structural transformation inside the systems under harsh operating conditions.