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CVD of nanocomposite coatings
Published in Kwang Leong Choy, Chemical Vapour Deposition (CVD), 2019
Hardide is an attractive replacement for hard chrome, which is to be phased-out due to environmental and health and safety considerations. Hard-chrome plating is widely used as a wear-resistant and anti-galling coating with some degree of corrosion protection, but the hexavalent chrome salt solutions used in the coating production, and the process effluents, are known carcinogens which represent major health, safety, and environmental problems [6]. Restrictive pollution-control legislation, such as EU REACH and US OSHA, apply further pressure on the plating companies, which increases the cost and reduces the future availability of hard-chrome plating. In response to this, some of the large users of chrome plating such as aircraft manufacturers launched programs to identify new and more environmentally friendly replacement technologies. HVOF thermal-spray coatings are often selected as a suitable replacement [11] but they could not be applied to internal surfaces, have a very rough finish as applied, and require expensive and complicated grinding which is not possible on complex-shaped parts.
CVD of nanocomposite coatings
Published in Kwang Leong Choy, Chemical Vapour Deposition (CVD), 2019
Hardide is an attractive replacement for hard chrome, which is to be phased-out due to environmental and health and safety considerations. Hard-chrome plating is widely used as a wear-resistant and anti-galling coating with some degree of corrosion protection, but the hexavalent chrome salt solutions used in the coating production, and the process effluents, are known carcinogens which represent major health, safety, and environmental problems [6]. Restrictive pollution-control legislation, such as EU REACH and US OSHA, apply further pressure on the plating companies, which increases the cost and reduces the future availability of hard-chrome plating. In response to this, some of the large users of chrome plating such as aircraft manufacturers launched programs to identify new and more environmentally friendly replacement technologies. HVOF thermal-spray coatings are often selected as a suitable replacement [11] but they could not be applied to internal surfaces, have a very rough finish as applied, and require expensive and complicated grinding which is not possible on complex-shaped parts.
Metal Plating and Surface Finishing
Published in E. Higgins Thomas, Hazardous Waste Minimization Handbook, 2018
Chrome plating is performed for one of three reasons: to enhance the corrosion resistance; to provide a bright metallic appearance; or to impart improved mechanical properties (hardness, lubricity) to the underlying base metal. Plating for corrosion protection or appearance is usually referred to as “decorative chrome plating” and generally involves adding a thin (a few thousandths of an inch) coating to a part. This process can be accomplished in a matter of minutes. Many parts are plated in a single tank, often using automated equipment, with large volumes of plating solution being “dragged out” of the plating bath each day.
Thermal oxidation of Ni – 40 wt.% W and Ni – 50 wt.% W coated copper
Published in Transactions of the IMF, 2023
C.N. Panagopoulos, E.P. Georgiou, G.D. Plainakis
During the last several decades there has been a high scientific and research interest to develop and apply nanomaterials to various industrial and technological applications1–3. One of the main goals is to replace hard chrome coatings. Indeed, chrome plating can have serious health hazards because it traditionally has required hexavalent chromium4,5. The European Commission is currently trying to restrict the use of hexavalent chromium in Europe6. However, even though a sunset date was set for September 2017, an extension was given for the next few years. This is because the transferring of know-how for new technology from science to industry can be rather limited. Some of the most promising candidate materials for hard Cr replacement are the nanostructured nickel-based coatings7–10. Among their wide variety and different types, Ni-W coatings are currently standing out due to their excellent technological properties11.
Pulse electro co-deposition of submicron-sized TiC reinforced Ni–W coatings: tribological and corrosion properties
Published in Journal of Asian Ceramic Societies, 2021
Serhat Dilek, Hasan Algül, Abdülkadir Akyol, Ahmet Alp, Hatem Akbulut, Mehmet Uysal
Electrodeposition is a well-known method for the production of high-performance metal or alloy coatings and this technique has been extensive used for protecting surfaces from friction and environmental degradation [1–3]. Chrome plating is the most common type of electrodeposition, with its high hardness, excellent corrosion, wear resistance and low friction coefficient. Conventionally, chrome coatings are generally performed in coating baths containing Cr+6 ions. The presence of Cr+6 ions in the electrolyte poses a great danger to human health and the environment, which limits this coating process [4–6]. Many studies have been focusing on replacing chrome plating, to improve the wear, mechanical and electrochemical properties [7–9].
The effect of saline environment on the fatigue behaviour of HVOF-sprayed WC–CrC–Ni coatings
Published in Surface Engineering, 2018
Alin Constantin Murariu, Anghel Vasile Cernescu, Ion-Aurel Perianu
High-velocity oxygen fuel (HVOF) [1] thermal spraying processes are used to protect the components with a wear-resistant layer [2–8], erosion–corrosion-resistant layer in aggressive environments [9–14] or with a layer used as a thermal barrier [15–18]. The thermally sprayed coatings made of WC–CrC–Ni powders are used in various applications to increase the service performance and lifespan of components in severe environmental working condition (e.g. cylinders, elbows, pipes, valves, vane pumps, mining equipment, downhole drilling motors) [19,20]. The process is used as an alternative technical solution to eliminate the adverse side effects of hard chrome plating on the environment and health.