Study on the effect of surface conditions on the tribological performance of hot stamping of aluminium alloys using a water-based lubricant

Abstract

The hot stamping of aluminium alloys is a pivotal manufacturing process for automotive lightweighting. However, severe tool wear constitutes a major obstacle to the mass production of aluminium alloy structural and safety components. Currently, no dedicated lubricants exist for aluminium alloy hot stamping, and few studies have systematically evaluated lubricant performance under such conditions. This study investigates the influence of a water-based lubricant on aluminium alloys hot stamping under representative processing conditions using a pin-on-disc tribometer. The lubricant achieved a significant 60% reduction in the coefficient of friction (COF). Nonetheless, the results reveal that lubrication effectiveness is highly sensitive to surface conditions, as interfacial pressure and stress distributions are contingent upon both surface orientation and roughness. Furthermore, tribological behavior is governed by a composite surface morphology, encompassing both the initial surface texture and the spatially and temporally stochastic distribution of compacted wear debris. Consequently, optimizing tool surface conditions under hot stamping parameters presents a promising strategy for substantially mitigating wear and extending service life.