Abstract:
The sliding contact between aluminum alloy sheet and H13 steel in hot stamping often?leads to severe wear and adhesive transfer, significantly degrading forming quality and tooling life.?This study simulates the actual solution-forming-quenching process of hot stamping on a self-developed sheet-and-strip high-temperature friction tester. This study reveals the influence of different normal pressures on the thermal tribological behavior between three types of surface-modified H13 steel, quenched and tempered (Q&T) H13 steel, Q&T H13 steel combined with ion plasma nitriding (PN), and Q&T H13 steel combined with PVD-TiN coating (PVD-TiN)) and high-temperature aluminum alloy. The experimental results reveal that increased normal pressure a higher friction coefficient and intensified adhesive wear. Both PVD-TiN coating and nitriding coating exhibit excellent friction-reducing performance under different pressure conditions. Under the medium pressure condition of 4.5Mpa, although the friction coefficient of the PVD-TiN surface modified tool is lower than that of the surface nitrided tool, the adhesive wear is more severe than that of the surface nitrided tool because the thinner coating is prone to local spalling, exposing the fresh metal surface. However, the compounds such as Fe?N and Fe?N formed by nitriding treatment can effectively inhibit adhesion. Under the high pressure condition of 5.4Mpa, the the PVD-TiN surface modified tool not only maintains a lower friction coefficient, but also the TiN particles formed on its surface can significantly reduce adhesive wear, showing better performance than the surface nitrided tool. The latter, however, deteriorates the contact condition of the friction pair due to the formation of Fe-Cr alloy aggregate particles caused by plastic deformation.