Wednesday, 14 December 2016

Concerns in REACH regulations in the EU and OSHA legislation in the USA over the toxicity and carcinogenic potential of source materials and bye-products of hard chrome plating (HCP) are driving engineers to seek a more acceptable alternative. Coatings specialist the Wallwork Group strongly advocate Nitron CA – a form of chromium nitride (CrN) that has significant technical and environmental advantages. It is substantially harder than HCP, but has similar properties of chemical and thermal resistance with even surface coverage and an attractive bright silver finish.

Nitron CA can be used in almost any application as a direct replacement for HCP. This includes high-load, wear surfaces, such as bearings where the low friction qualities and hardness of the material, double that of HCP, improve performance. Heavy duty tooling such as stamps and dies is another application as is use on medical devices where harsh and frequent cleaning is required that could degrade and undermine the hygiene of other surface treatments.

The coating follows the contours of the part closely, maintaining even coverage, especially on edges and corners. It shares many of the characteristics of HCP: it is heat resistant and can be applied in high thicknesses, it is chemically stable and corrosion resistant, the surface is smooth and therefore naturally lubricious.

Applied by physical vapour deposition (PVD) under conditions of a vacuum and at low temperature the Nitron CA process is environmentally safe, using solid, non-toxic and fully recyclable source materials. The inert process gasses used present no hazard and there are no toxic waste products.

Application takes place within an enclosed vacuum chamber that is electrically charged. The donor material is placed in a small crucible and bombarded with a high energy electron beam to create a vapour of micro fine particles. Components, placed on racks, are subject to a negative electrical charge and rotate through the vapour to attract the microscopic droplets which are drawn to the surface to create an even film that can vary in thickness according to the application.

The coating machines used in the process are manufactured by Wallwork and so the company has a complete understanding of every aspect PVD. Skilled technologists can advise on the most suitable process design to achieve a given performance with full validation and quality assurance.

Nitron CA is just one in a family of advanced coatings produced by Wallwork. The company is happy to provide technical advice on any technical coating issue and advise on the most suitable coating for each application to achieve the best technical performance and meet commercial requirements. As one of the largest PVD coating companies in Europe, the company can scale production from research and development to batch production and up to full scale manufacturing volumes.

More Information
Simeon Collins, Sales Director
Tel. +44 (0)161 797 9111 Fax. +44 (0)161 763 1861
E-mail: simeon.collins@wallworkht.com Web: www.wallworkht.com
Wallwork Group, Lord Street, Bury, Greater Manchester, BL9 0RE

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