Abstract
Ultrasonic waves with a frequency of 25 KHz were used to enhance the acidic chemical recycling of tungsten heavy alloy (WHA) scrap class 2 HA175 with a typical composition of Ni-5.25 wt%, Fe-2.25 wt%, and W-92.5 wt% to recover the tungsten powder. The experiment demonstrated that the scrap sample exposed to ultrasonic waves produced a significantly higher amount of tungsten powder with a submicron particle size. The recycled tungsten powder was utilized to manufacture a new tungsten heavy alloy sample class 2 HA175 with the same alloy composition as the above. The elemental powders were mixed mechanically, cold compacted, and sintered at 1500◦C in a vacuum furnace. The microstructure, phase structure, and composition of the sintered WHAs were investigated by Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD). The recycled sample's density and hardness were higher than the original, in which the hardness increased from 312 to 340 HV, whereas the wear rate and coefficient of friction were decreased by about 50%. The longitudinal (VL) and shear (VS) velocities for both samples were examined using ultrasonic (NDT).