Flow Field Analysis And Optimization Of High Velocity Oxygen-fuel Flame Spraying Process (HVOF)

Thermal spraying with the HVOF technology is widely used nowadays. On many occasions, the quality of thermal spraying plays a decisive role. Because of complex spraying process, which involves lots of physical and chemical change, it has many process parameters and some of which have interactive effect. In order to study the mechanism of HVOF spraying process and obtain high performance coatings, people have done much research. It’s accurate and convenient to acquire change rule of velocity field, temperature field, pressure field and so on of HVOF thermal spraying process by means of numerical simulation method. It can provide theoretical guidance to improve the performance of coatings.The combustion calculation model is established with analysis of the HVOF combustion process and combustion theory, which takes American METCO Company’s Diamond-jet spraying system for reference, oxygen as help gas and propane as fuel gas. The CFD software AN SYS CFX is used to solve the established combustion model with the finite volume method. On the basis of influence of changes of gas flow rate and the spraying gun geometric parameters on velocity, temperature and pressure of flame flow, the general rule of flow field is obtained. In order to optimize spraying process parameters and provide reference for designing the HVOF spraying gun structural and choosing operating parameters, the interactive effect between spraying flow rate and spraying gun geometric parameters is analyzed at the same time.