Know 3 types of surface treatment in molds

Anyone who works with plastic injection molds knows this: the treatment of mold surfaces is indispensable. There are several surface treatments on the market, each suitable for a specific application or material.

That is: you need to know the available solutions to be able to choose. There are three types of mold surface treatment, find out which one is right for your need! 

Surface temperature

This treatment increases the hardness of the material up to 10 millimeters deep. Therefore, it’s suitable for materials that suffer tension and need toughness, such as gears. The operation achieves better results when the furnaces used operate under vacuum, because the absence of air guarantees some advantages. This is a clean process that is easier to control within lower temperature tolerances.

In addition, another detail of this treatment is that it can be cooled by injecting nitrogen gas under pressure into the heated parts. This is done through oil baths or molten salt baths, which are less and less popular due to the aggressions that can cause the environment.

Plasma nitriding

With nitriding, high surface hardness can be achieved in 0.3 mm layers without dimensional changes and scale. As such, it can be applied to prefabricated and tested molds, which significantly increases wear and scratch resistance.

This is one of the most important processes in thermochemical surface treatment for metallic materials in order to increase service performance. Therefore, it’s used when it’s desired to keep the core of the material in high tenacity conditions, combined with a hard surface and greater resistance to wear, fatigue and corrosion.

However, unlike other techniques, this allows precise control of the precursor species of the process. Resulting in a high-quality product with microstructural control of the nitride surface according to the type of material and the application of tools. 

Hard chrome

In this type of treatment, a layer between 0.01 and 0.02 mm is deposited on the tool. However, the pollutants generated, and the possible slippage decrease its application in the market.