Why PVD coating is still available at low temperature

The advantages of PVD coating that can be used for molds and their components have long been seen in various documents: PVD coating can reduce the production cycle of molds, simplify the mold filling process, make molds have better wear resistance, reduce the demoulding force and increase productivity. However, due to the high temperature generated by the arc deposition process, PVD coatings can only be applied on die steel and parts at 200~260 ℃ (400~500 ° F). However, the tempering temperature of the mold is usually lower than 260 ℃ (500 ° F), so this will cause damage to the mold. The additional tempering process will increase the cost and reduce the surface hardness normally required during processing. A new technology can reduce the application temperature of the coating to below 200 ℃ (390 ° F) without reducing its performance. This development also provides many opportunities for mold manufacturers, designers and injection molding manufacturers to select materials for new applications.

Common PVD coating

Because PVD coatings (such as TiN, TiAlN and CrN) are only a few microns thick and harder than steel, they are valuable for mold manufacturers and molders. The high hardness makes the coating wear resistant, while the ceramic component in the coating makes it corrosion resistant and improves the demoulding performance. The inherent lubricity improves the mobility of the mold containing PVD coating, so that its filling speed is faster and the mold cycle is shorter.

PVD coating is mainly used for ejecting guide pin, mold cavity and mold core. Its friction characteristics can avoid retardation and corrosion, and in some cases, lubricant and release agent are not required. The hardness and wear resistance of the coating can also protect the mold from the hot gas corrosion of the filled resin containing a lot of glass or minerals, PVC, CPVC and other materials.

PVD coating is usually applied when the arc deposition temperature is 400~500 ℃ (750~930 ° F), which is very suitable for steel with higher tempering temperature (such as M2 and CPM grades). However, PVD coating can not be used in cold work die steel, copper alloy and die steel used in plastic processing due to high deposition temperature.