Tribological performance of borided tool steel with minimum bio-lubrication for sheet metal forming applications

AISI D2 steel is widely used in manufacturing dies for sheet forming operations, where lubricants are essential to prevent wear. With a growing focus on reducing the environmental impact of manufacturing, there is increasing interest in exploring alternative lubrication methods to minimize the environmental footprint. This study examines the tribological performance of borided AISI D2 tool steel lubricated with a minimal quantity of biodegradable oil. Pin-on-disk tests were conducted to evaluate the tribological performance of borided and unborided AISI D2 tool steel under lubricated conditions using a mineral base oil and Jatropha oil. Cylindrical pins of AA 6061 T6 aluminum alloy and AISI 304 stainless steel were used as counterparts. Surface damage analyses were performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and optical profilometry. The results indicate that the boriding treatment reduced the mass loss of stainless steel pins by 18 % and aluminum pins by 30 % when lubricated with neat mineral oil. Furthermore, the biolubricant significantly lowered the coefficient of friction (CoF) between aluminum and borided AISI D2 steel, while reducing the mass loss of stainless steel and aluminum by 50 % and 70 %, respectively.