Did you know,...

that microporous chrome as a surface not only provides optimal resistance to corrosion but also a high level of gloss? A three-layer nickel base coating system forms the basis for chrome surfaces with considerably improved corrosion resistance and a very hard, decorative, glossy finish.

Galvanised parts consisting of plastic and metal determine appearances in automotive and mechanical engineering, microscopy optics and medical engineering as well as in the consumer goods and domestic appliances industry. A metallic surface finish in particular underlines the visual appeal of electroplated surfaces. At the same time, the automotive industry in particular has high requirements regarding the corrosion resistance of surfaces, especially when it comes to exterior car parts. When looks and corrosion protection are equally important, the best solution is microporous chrome.The Holzapfel Group has developed a microporous coating system that satisfies the highest possible requirements and the surface meets GME 00251 and DBL standards, including the required Corrodcote tests, among other standards. It consists of a tri-nickel coating (three layers) for which firstly a semi-gloss nickel layer and then a gloss nickel layer are precipitated. The third coating comprises a thin nickel precipitation that leads to the forming of tiny pores during the subsequent chromium plating due to the accumulation of inert micro-scale particles. The following layer of chrome is precipitated by the deposited, non-conductive particles with minute pores. These purposely introduced fine disturbances to the surface cause the corrosion current to spread to a large number of small areas. The process is supported by defined electrical potential differences in the first two layers of nickel so that the otherwise typical pitting corrosion is unable to develop.The three-layer nickel base coating system makes it possible to produce chrome surfaces with considerably improved corrosion resistance and a very hard, decorative, glossy finish. In contrast to a conventional gloss chrome finish, microporous chrome made by Holzapfel does not cloud or lose its gloss and is also highly suitable for exterior use. Non-glossy surfaces can also be produced by correspondingly pre-treating (grinding, blasting, etc.) the original surfaces of the material.In order to achieve long-term high resistance to corrosion, the parameters required for the coating system are set and constantly controlled by means of special electrolyte settings as well as continuous process bath monitoring. A wide variety of base materials are coated using this system, including steel, stainless steel, brass, bronze, aluminium, sintered metals and also castings. Microporous chrome is thus used for a great many applications, such as exhaust pipe covers, retention bars or for elements that stabilise the coefficient of friction in exhaust systems with extreme exposures to temperature.