Impact induced phase transformation in Ti-5Mo-5V-2Cr-3Al alloy

Dynamic testing of Ti-5Mo-5V-2Cr-3Al (TB10) alloy was carried out by a split Hopkinson pressure bar (SHPB) technique. The results showed that the strain rate sensitivity was deeply influenced by microstructure. With the same strain rate, adiabatic shear bands were observed in TB10 alloy samples which were in the solution treated and ageing (STA), and, solution treated and diplex ageing (STDA). Moreover, there were cracks along the adiabatic shear bands. Meanwhile, there was no adiabatic shear band observed in the sample which was in the solution treated condition, the deformation of its grain was homogeneous, and it was relatively insensitive to adiabatic shearing sensitivity. Under high strain rate, stress-induced martensite phase transformation happened to the sample in the solution treated condition. The educt with list structure within the β-grain was made up of β-phase and martensite phase. Because some of the impact power was consumed in the transformation process, the sample avoided reaching the critical condition of material destabilization and forming ASB, and the stress-induced martensite phase had high uniform elongation and biggish plasticity, so the sample still had good dynamic bearing capacity.