Meaning
Ceramic surface treatment is applied to tool steel to increase its surface hardness and reduce the coefficient of friction. A titanium nitride coating is frequently used on the tips of injection screws, check valves, and mould cavities to protect them from the abrasive wear of glass-filled resins. This gold-coloured layer is applied using physical vapour deposition and provides a significant increase in the service life of the components.
Wear Resistance
Hardness of the treated surface can reach over 2000 vickers, which is much higher than that of untreated tool steel. Using a titanium nitride coating prevents the washing away of the metal at the gate areas where the melt velocity is highest. This protection is critical for maintaining the tight tolerances of high-volume parts over millions of cycles.
Release Improvement
Low friction properties of the ceramic layer help the plastic part to release more easily from the mould surface. In many cases, the titanium nitride coating reduces the need for external release agents, which can contaminate the parts and interfere with secondary operations like painting or bonding. The smooth surface also minimizes the buildup of burnt resin or plate-out from additives.
Thermal Stability
Ceramic layers are capable of withstanding high processing temperatures.
