Evaluating the Replacement of Galvanic Cr Coatings

Abstract

Excellent resistance to wear and corrosion predetermine galvanically deposited chromium coatings for utilizatio in the automotive and aerospace industries [1-4]. The disadvantage of this technology is creation of thickness that is not uniform (Table 1). Their positive features include particularly high adhesion to the steel surface, and a hardness of 8 GPa at room temperature and above 4 GPa after ignition at temperatures of up to 600ºC. Technology of Hard Chrome is typically used to protect the surface against abrasive wear and to the recovery of worn surfaces, original dimensions, and shape. These conventional electroplated chrome layers formed from an electrolyte with hexavalent chromium have been used for 120 years. However, over the last decade there has been increased pressure on health and the environment. One of the acceptable solutions was proposed replacement of the conventional process of galvanic plating solution to hexavalent chromium Cr 6+ for environmental technologies. One of the most acceptable ecological options is electro-plating using a trivalent chromium electrolyte, thermal spraying, chemical vapour deposition (CVD), or physical vapour deposition (PVD). We examined coatings composed of several elements deposited alloy multiple combinations of elements such as Cr-C, Ni-Mo [6-7], Ni-Co [2, 5, 8-9] and Ni-Mo-Co