Effect of Heat Treatment on the Microstructure and Properties of Cold Sprayed Ta Coating Layer

This study investigaed the effects of heat treatment on the Microstructure and properties of cold sprayed Ta coating layer. Pure Ta powder with an average particle size of 24µ and non-uniform globular shapes was used. High density coating layer (thickness 1.73 mm) with a porosity of 0.04% and hardness of 550Hv could be manufactured using a cold spray process. Heat treatment experiments were conducted for one hour at 800°C, 900°C, and 1000°C respectively in vacuum environment. As post heat treatment temperatures increased, porosity decreases from 0.04% to 0.025% (density increases) could be identified. According to the observation of microstructures, as heat treatment temperature increased, boundaries between particles became vague and the structure became denser. Through phase analysis, it could be seen that minute quantities of Ta₂O₅ oxide existed on heat treated samples of Ta coating layer. (supported by "the program for the Training of Graduate Students in Regional Innovation", Kora)