Ti–Al–V powder metallurgy (PM) via the hydrogenation–dehydrogenation (HDH) process

The present investigation compares two routes for processing of sintered Ti–6Al–4V products via the hydrogenation–dehydrogenation (HDH) process: single and double step. DTA-TG of the titanium hydride powder indicated the occurrence of two endothermic reactions, one occurring around 375 °C and the other around 523 °C. The first transition might be related to the beginning of the hydride decomposition, the (δ-TiH 2/Tiβ+δ-TiH 2) transus, while the second transition might be related to the final hydride decomposition, given by (δ-TiH 2+Tiβ/Tiβ) transus. The microstructure of the sintered samples produced by both routes consist of α platelets and an interplatelet β phase. The morphology of the β phase seems less continuous for the sample sintered from dehydrogenated powder, while the microstructure of the sintered sample obtained from hydrogenated powders showed lower volumetric fraction of pores.