Mechanical behaviour of pressed and sintered titanium alloys obtained from master alloy addition powders

The fabrication of the workhorse Ti–6Al–4V alloy and of the Ti–3Al–2.5V alloy was studied considering the master alloy addition variant of the blending elemental approach conventionally used for titanium powder metallurgy. The powders were characterised by means thermal analysis and X-ray diffraction and shaped by means of uniaxial pressing. The microstructural evolution with the sintering temperature (900–1400 °C) was evaluated by SEM and EDS was used to study the composition. XRD patterns as well as the density by Archimedes method were also obtained. The results indicate that master alloy addition is a suitable way to fabricate well developed titanium alloy but also to produce alloy with the desired composition, not available commercially. Density of 4.3 g/cm3 can be obtained where a temperature higher than 1200 °C is needed for the complete diffusion of the alloying elements. Flexural properties comparable to those specified for wrought Ti–6Al–4V medical devices are, generally, obtained.

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► The master alloy addition approach to produced titanium alloys is studied.
► The diffusion processes that take place to obtain a homogeneous microstructure are analysed.
► The microstructural evolution of the alloys with the temperature is evaluated in dept.
► Bending properties of PM Ti–6Al–4V and Ti–3Al–2.5V are measured.