A TECHNIQUE OF FABRICATING COMPLEX SHAPED THIN WALLED COMPONENTS IN HARD MATERIALS USING A HIGH VELOCITY OXY-FUEL (HVOF) THERMAL SPRAYING PROCESS

摘要

This paper presents a study of manufacturing near net complex shaped hollow components using a High Velocity Oxy-Fuel (HVOF) thermal spraying process. Materials used were tungsten carbide-cobalt, a nickel based alloy, and stainless steel. Forming core of various shapes and sizes including collapsible ones were made, onto which powder materials were sprayed using the HVOF thermal spraying gun. The sprayed deposits took the outer shape of the forming core. After cooling, these sprayed components were separated from the core blocks without damaging the core blocks. The primary objective was to investigate the suitability of the technique as a viable production process. Different process parameters including spraying temperature, core material, post spray heat treatment and releasing agent thickness were studied in order to determine their appropriate ranges for manufacture of these components. Properties of the components such as hardness and porosity were also measured to establish component quality.