Parameter Variation in Planetary Ball Milling of Titanium Aluminide Powder in XHV‐Adequate Atmosphere

Given the high oxygen affinity of titanium aluminides, their powder particle surfaces develop an oxide layer. Due to the oxides, processing via the conventional powder metallurgy route is not possible, as they reduce particle cohesion and thus compromise the green strength of TiAl‐billets. To prevent oxidation, this study utilizes an extremely high vacuum‐equivalent process atmosphere with an oxygen content of <10 −16 ppm v . By performing ball milling in a silane‐doped, low‐oxygen environment, oxide‐free metal surfaces on the prealloyed TiAl powder particles are created. The milling parameters, including milling speed, milling duration, and ball‐to‐powder ratio, are varied to enhance the processability of the powder. The goal is to achieve a mechanically stable green body with the highest possible density. The milled powder is analyzed in terms of particle size distribution and morphology. The resulting green compacts are evaluated for their density, vibration resistance, and tensile splitting strength. Green bodies with tensile splitting strengths up to 11.9 ± 1.0 MPa could be achieved from TiAl powder with an effective milling time of 2 h. This highlights the influence of milling conditions on the mechanical properties of the green bodies, as the milling conditions determine the formation of the reactive surfaces.