A comparison of field assisted hot pressing and hot isostatic pressing for gas atomized Ti–22Al–26Nb(at.%) and Ti–22Al–26Nb–5B(at.%) powders

Ti–22Al–26Nb(at.%) and Ti–22Al–26Nb–5B(at.%) compacts were processed from gas atomized prealloyed powders by field assisted hot pressing (FAHP) for between 600 1200 s at temperatures 725 1070 °C the resulting microstructures compared. The average powder diameters ranged 50 100 μm, where both B-containing FAHP contained elongated B-rich needles. microstructure in depended on processing temperature. For less than or equal to 960 °C, porosity was evident compact, greater observed with decreasing Processing 980 resulted minimal three-phase containing a mixture of orthorhombic, α2, body-centered-cubic (BCC) phases, longer times led microstructural coarsening. compared those consolidated 1027 4 h using isostatic (HIP). HIP processing, exhibited finer prior-BCC grain sizes. Compositional analysis phase within Ti–22Al–26Nb compact suggested that it could be B27 orthorhombic structure B2TiNb stoichiometry. Overall, shown viable metallurgy technique intermetallic Ti2AlNb based alloys.