Microstructured and nanostructured WC-Co composite coatings can be deposited by HVOF starting from commercial composite powders. However, the reduction in powder size of the ceramic reinforcement is responsible for a significant increase of WC reactivity, enhancing the decarburation phenomena taking place within the spraying torch, and potentially affecting the mechanical and tribological properties of the deposited coatings. In order to limit the thermal degradation of the reinforcement, it is therefore necessary to strictly control the main combustion parameters of the torch, such as composition, velocity and temperature of the combustion gases. Using a CFD code, thermo-chemical and gas-dynamic properties of the gas flow within an HVOF JP-5000 (Hobart Tafa Inc.) torch were simulated. Results of the simulation were used to reconstruct the thermo-chemical history of the powders during their residence in the gas stream.
CFD simulation of an HVOF process for the optimization of WC-Co protective coatings / Bartuli, Cecilia; F., Cipri; Valente, Teodoro; Verdone, Nicola. - STAMPA. - 7:(2003), pp. 71-83. (Intervento presentato al convegno Sixth International Conference on Computer Methods and Experimental Measurements for Surface Treatment Effects, Surface Treatment VI tenutosi a IRAKLION, GREECE nel 11 - 13 March 2003).
CFD simulation of an HVOF process for the optimization of WC-Co protective coatings
BARTULI, Cecilia;VALENTE, Teodoro;VERDONE, Nicola
2003
Abstract
Microstructured and nanostructured WC-Co composite coatings can be deposited by HVOF starting from commercial composite powders. However, the reduction in powder size of the ceramic reinforcement is responsible for a significant increase of WC reactivity, enhancing the decarburation phenomena taking place within the spraying torch, and potentially affecting the mechanical and tribological properties of the deposited coatings. In order to limit the thermal degradation of the reinforcement, it is therefore necessary to strictly control the main combustion parameters of the torch, such as composition, velocity and temperature of the combustion gases. Using a CFD code, thermo-chemical and gas-dynamic properties of the gas flow within an HVOF JP-5000 (Hobart Tafa Inc.) torch were simulated. Results of the simulation were used to reconstruct the thermo-chemical history of the powders during their residence in the gas stream.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
