PVD Coating Treatment On The Surface Of Aluminum Alloy Die Casting Mould

- Jun 04, 2018-


According to the failure mode of aluminum alloy die casting molds, PVD coating is a very good protection method for it. The following table shows the protective effect of PVD coatings on aluminum alloy die-casting molds.

 

CoatingColorFeatures
CrN
Silver

Chromium has anti-adhesive properties and it is a good barrier to aluminum permeability. CrN 

coating has wonderful high temperature resistance (about 800 °C), corrosion resistance and 

nitriding resistance, and it is also has good welding resistance to non-ferrous metal.

TiAlNPurple

As the TiAlN coating contains aluminum, the coating not only has high temperature oxidation

resistance(about 800°C), but also can provide optimum protection to the processing tool under 

dry or high speed conditions. In addition, due to poor heat conductivity, aluminum die casting 

can hinder heat conduction to the mold material, so it can prevent cracks in the mold.

TiN
Gold

TiN coating has good high temperature resistance (about 600 °C), corrosion resistance and

 wear resistance, but the protection for molds is not as good as other coatings.

AlCrNBlack

AlCrN coating has the advantages of oxidation resistance, high temperature resistance (about

1100 °C), wear resistance and high hardness. So it is very suitable for mold core, slider, insert, 

insert pin and other molding parts, the performace is extremely good.


The method of surface coating is generally used to prevent the aluminum alloy's cracking of the die casting mold and greatly prolong the life of the mold. However, choose of the coating must follow some principles:

 

1. The coating can withstand high temperatures.

2. The coating has high chemical stability and it does not react with the aluminum alloy.

3. The coating is very dense and it can block the diffusion of A1 atom.

 

Among the surface coatings, CrN and AlCrN are the best choices. They can withstand 700 °C high temperature with high chemical inertness, also, these two coating are very dense to form a tight protective layer on the mold surface to prevent AI atoms from penetrating to the substrate.