The role of diamond-like carbon coated drills on minimum quantity lubrication drilling of magnesium alloys

► Non-hydrogenated DLC (NH-DLC) coated tools were evaluated in Mg alloy drilling. ► NH-DLC in dry drilling generated high temperature and initiated recrystallization of Mg. ► High drilling temperature correlated with the high coefficient of friction and caused Mg adhesion to tool. ► NH-DLC coatings in water spray reduced Mg adhesion to tools and drilling torque. ► Relationships between the microstructures and drilling torque were developed.