HVOF spraying of metal alloys with Natural Gasand Oxygen-Air mixtures

There is a growing interest in the industry to find processes able to close the gap between CS and HVOF spraying. Air-Fuel processes have proved to be a viable technology with many practical advantages over conventional HVOF and CS systems. This work deals with the development of Cu, different Ni -based and stainless steel coatings using a proprietary HVOF system which has been under development at TECNALIA during the last three years. The system is operated with natural gas as fuel and the process temperatures are adjusted by injecting compressed air and oxygen to the combustion mixture. The process parameters have been optimized based on the resulting coating micro-structure and application relevant properties like the content of oxygen in the coating and the hardness. The results collected so far demonstrate the potential of this technology for the cost-effective manufacture of high quality metal coatings.