Comparison of tribological and wear performances of AlSi and Zn coatings in hot stamping of boron steel sheets

The paper presents the results of experimental investigations on the tribological performances of AlSi and Zn coatings applied to 22MnB5, reproducing the different thermal conditions at the blank-die interfaces. Frictional and wear tests, reproducing the thermo-mechanical conditions typical of hot stamping, were carried out in the temperature range from 800 °C down to 600 °C. The results show lower friction coefficients for the Zn coating. For both the coatings, the dies wear appears as a combination of adhesion and abrasion, with the latter more relevant at the lower temperatures. Both the coatings show worse performances when the test temperatures are decreased.