| Abstract Scope |
The production of Ti-6Al-4V powder feedstock from machining scrap is an attractive route for additive manufacturing and powder metallurgy, but requires control of powder morphology, phase formation, and oxygen contamination. This study explores a low-temperature, energy-efficient route for converting Ti-6Al-4V machining scrap into powder through hydride-assisted reactive ball milling. Machining chips generated under different cutting conditions are ball-milled at room temperature in oxygen-free, hydrogen-bearing atmospheres to promote hydrogen uptake, hydride formation, and chip fragmentation. Because chip structural characteristics can influence milling response, distinct chip categories are compared to assess their effects on hydrogen absorption kinetics, comminution behavior, and resulting powder characteristics. Hydrogen uptake is monitored using an instrumented ball-milling system, while laser-induced breakdown spectroscopy provides location-specific oxygen measurements. Scanning electron microscopy and X-ray diffraction are used to evaluate the initial chip microstructure, powder morphology, hydride phase formation, and microstructural changes. |