Behavior of Thermally Sprayed WC-Co Layers on 5086 Aluminum Alloy and 304 L Stainless Steel

Thermal spraying is a process for surface coating by projecting a material in powder or in wire form on a material with a previously prepared surface. The materials used in our study are 5086 aluminum alloy and 304 L stainless steel with various surface qualities: polished 120, mirror polished and sandblasted. The projection powder is a combination of "ceramic-metal" WC-Co whose average grain size is 30 microns. The layers thicknesses obtained after 3 passes vary between 90 and 120 microns depending on the operating conditions: gas protection, temperature and surface condition. Indentation tests at the substrate-layer interface and micrographic sections revealed the roughness importance to allow a better layers grip.