Study of Wear Phenomena of Coatings for Die-Casting

During high pressure die casting process, molten metal (aluminum) is injected with a die casting machine under considerable pressure into a steel mold or die to form products. Usually, during the process, the components can undergo several damages such as hot and abrasive wear, metal corrosion and plastic deformation. In order to increase the die life, a surface modification through the application of a Physical Vapour Deposition (PVD) coating can be done. This paper deals with the wear behaviour of a nanocomposite coating (AlSiTiN) deposited onto hot-working tool steel and onto a ion nitrided hot-working tool steel. The characterization includes: nanoindentation test, adhesion test, wear testing at high temperature and optical profilometry. Results showed that the nitriding step had a beneficial effect in terms of hardness, while adhesion between the coating and the substrate was reduced . The film exhibited good wear resistance, with adhesion phenomena as main mechanism.