The general method of process maps to control thermal spray processes has been applied to monitor the deposition of WC-Co by High Velocity Oxygen Fuel (HVOF). A selected number of particle state conditions (velocity and temperature) has been run to produce a variety of coatings. Microstructure, mechanical properties, wear resistance, thermal conductivity, decarburization and residual stress state, were evaluated and compared. A second order process map for sliding wear, impacting particle erosion and abrasive wear control can be constructed from the process map to provide the limits within which the particle state can be changed to achieve a predefined coating specification.
The mechanisms behind the wear resistance are discussed within the context of analysis of splats, mechanical properties and process maps.