The effect of hydrogenation on the fracture of Ti2AlNb-based alloy during ball milling

In this work we have studied the effect of phase composition and microstructure of a rapidly solidified Ti2AlNb-based alloy containing hydrogen on deformation of the alloy during ball milling and production of a fine-dispersed powder. Hydrogen is introduced into the alloy up to a concentration of 2.0 wt%. The X-Ray diffraction (XRD) analysis and Scanning Electron Microscopy (SEM) show that the alloy has the following phase compositions depending on hydrogen content: beta + O, beta/beta-hydride, beta/beta-hydride + intermetallic hydride (Ti2AlNbHx) or a single-phase intermetallic hydride. It is found that in the hydrogenated beta + O alloy containing a small amount of hydrogen a strong decrease in ductility occurs, but this does not affect the ball milling and synthesis of the fine-dispersed powder. Efficient milling of the rapidly solidified alloy has been achieved when hydrogen content was 1.2 wt% and exceeding this value when a transformation from the H saturated solid solution into a hydride phase is observed in the alloy or the formation of a single phase hydride occurs. (C) 2022 Elsevier B.V. All rights reserved.