Nanostructured CVD Tungsten Carbide Coatings Protect Non-Line of Sight Surfaces against Abrasion and Corrosion

摘要

Hardide is a nano-structured Tungsten Carbide coating produced by Chemical Vapour Deposition (CVD). The coating crystallised atom-by-atom from gas media produces conformal pore-free layer on both internal and external surfaces, complex shapes, non-line of sight areas, such as pump impellers, inside small ID cylinders, dies. 50 microns thick coating can be polished to 0.3μm Ra without need for grinding. The ability to coat non-line-of-sight areas and facilitated post-coating finishing open new applications for hard coatings on complex shape parts with precise dimensions, which are difficult to coat by other technologies. Hardide coatings nano-structure combines high hardness with enhanced toughness, this combination maximises coating resistance to wear and erosion. Pore-free Hardide protects parts against corrosion and acids: H_2S, HCl. Reducing wear and erosion rates by two orders of magnitude the Hardide coatings extend life of critical parts of oil drilling tools, aircraft components, pumps and valves operating in abrasive, erosive and corrosive environments, and cuts down-time costs.