Tungsten Coatings as a Protective Layer on Surfaces in Contact with Molten Metals

Hot wall low temperature (500{degree sign}C) Chemical Vapour Deposition (CVD) is used to coat steel surfaces with a W or WC coating to protect the steel substrate against the attack of molten metals. Wettability measurements show that the W coating is almost not wetted by Zn, indicating excellent barrier properties against corrosion and soldering. It was also found that surface roughness influences the thermal barrier properties of the W(C) coating which can be beneficial to minimize heat checking.