The effect of microstructure and strain rate on the 25 °C and 700 °C compression deformation behavior of powder metallurgy processed Ti-45Al-2Nb-2Mn (at.%)-0.8 TiB2 (vol%) alloy

The effect of microstructure and strain rate on the room-temperature (RT) 700 °C compression deformation behavior a powder metallurgy processed ?-TiAl intermetallic alloy, Ti-45Al-2Nb-2Mn (at.%)-0.8 (vol%) TiB2, was investigated. Samples were heat-treated to obtain duplex two-phase ?2+? two nearly fully-lamellar microstructures with different lamellar spacings ?-phase volume fractions. Compression experiments performed minimum 10% true under rates 10?2, 10?3, 10?4, 10?5 s?1. strength, sensitivity, colony size, interlamellar spacing, microhardness dependent microstructure. exhibited higher strengths than for all testing conditions. sensitivity index (m), tended increase increasing temperature, deformation, m increased strain. apparent activation volumes, decreased at °C. Scanning electron microscopy observations showed that cracking preferentially occurred within ? phase extent strain, rate. Overall, RT considered be controlled by dislocation glide, while elevated likely thermally activated process controlling glide associated forest junctions acting as pinning points.