Applications
The Applications of SilCor® CrN
Substitution of Hard Chrome - Mechanical and Plant engineering and construction
The chemical resistance of chromium nitride is at least as good as that of hard, engineered chromium. Its visual appearance is very similar. However, the mechanical hardness of SilCor®CrN chromium nitride exceeds that of hard chrome by orders. Therefore, CrN even at a much smaller thickness results in a better wear protection of coated parts. This has the aditional advantage of much better size accuracy for CrN coated parts. In principiple, all metallic parts can be coated with chromium nitride. An especial advantage of the coating appears in the case of aluminum and titanium alloys. As an extra surplus all plastic materials, glasses and ceramics are convenient for CrN coating without an especial surface treatment!
Compacting Tools
Compacting tools are widely used in pharmaceutical industry but also in the production of domestic home chemicals as e. g. dishwasher tablets. These tools undergo an extreme strain at their bearing surface: Applied forces result in a pressure in the GPa-range. There is strong abrasive wear due to shearing of the grains of the powder to be compacted, which often contains hard crystals. In addition, chemically reactive substances may be released, what results in corrosion of the metallic tools. SilCor®CrN chromium nitride coatings withstand these strains much better than hardened steel. In consequence, the lifetime of compacting tools increases by up to 350% in comparison to uncoated tools. A further advantage is the anti-adhesion effect of the CrN - due to reduced sticking at the tool surface the quality of the tablets increases.
Photo: A chromium target (cathode) which has been in use for the deposition of chromium nitride. The zone of strongest material removal (erosion groove) is clearly visible. In the front there are CrN coated compacting tools (so called "stamps").
Plastics Machining
Because of the high hardness and the low sticking against plastic moldings, chromium nitride is suitable for the processing of elastomer, thermoplastics and thermosetting plastics. It can be used to coat injection molds, form molds and extrusion tools. Especially for filled moldings for glass fibre reinforced plastics, the SilCor®CrN chromium nitride coatings guarantee a long lifetime of the tools and components. In addition, the improved release properties due to the coating results in a better surface quality of the molded parts.
Metalworking
Chromium nitride is suitable for coating of cutting tools, especially for processing of non-ferrous metals as copper. In this case the coating is helpful to prevent the formation of cold metallic buildup welding. SilCor®CrN coatings are also successfully applied in die casting of aluminum and magnesium parts.