The application of PVD coating technology on aluminium alloy forming workpieces mainly includes chromium nitride coatings, aluminium titanium nitride coatings and titanium nitride coatings, which have their own characteristics and advantages and are suitable for different processing needs.
(1) Chromium nitride coating (CrN) has a silvery-white appearance, and its main characteristics include anti-adhesion, good impediment to aluminium penetration, as well as high-temperature resistance, corrosion resistance and nitriding resistance, and high resistance to fusion bonding of non-ferrous metals. This coating can effectively solve the problem of sticky aluminium, burns, and reduce bending deformation.
2) Titanium Aluminium Nitride coating (TiAlN) shows purple colour, because it contains aluminium element, it not only has the resistance to high temperature oxidation, but also can play the best protection performance to the machining tools under dry or high speed conditions. It also prevents heat transfer to the mould material and prevents cracks in the mould.
(3) Titanium nitride coating (TiN) is golden yellow, with high temperature resistance and good abrasion and corrosion resistance, suitable for the protection of aluminium alloy die-casting moulds, but relative to other coatings, its protection of moulds is weak.