Evaluation of process parameters and ultrasonic vibration in hot pressing of metal powders

This paper investigated the effects of process parameters and ultrasonic vibration in the hot pressing of spherical Ti-6Al-4 V powders. The parameters were the consolidation temperature (750, 850, and 950 degrees C), densification pressure (10, 20, and 30 MPa), and ultrasonic power (0 and 300 W). Relative density, Vickers hardness, and Transverse Rupture Strength (TRS) were used to evaluate their influences. The results show that applying ultrasonic vibration could improve the properties of the final part, namely increasing initial relative density, final relative density, Vickers hardness, and strength of specimen are 11.7%, 11.1%, 86%, and 130%, respectively. It is found that the temperature and pressure have different effects on the ultrasonic efficiency so that ultrasonic efficiency reduces with increasing hot pressing pressure while increasing temperature (up to 950 degrees C) enhances ultrasonic efficiency. The finding shows that the consolidation of Ti-6Al-4 V powder could be significantly improved by using high-power ultrasonic vibrations.