Microstructure and Mechanical Properties of Ti-15Mo Alloy Prepared by ECAP

Metastable beta titanium alloys are perspective materials for use in biomedicine due to their excellent mechanical and physical properties, which can be improved by severe plastic deformation by reducing grain size and inserting a high degree of deformation. Ti-15Mo alloy was subjected to 1-4 passes of equal channel angular pressing in a die with channels intersecting at an angle of 120 degrees at the temperature of 250 degrees C. The microstructure observed by means of electron backscatter diffraction showed deformed and highly twinned structure, but the deformation was not sufficient for achieving an ultrafine grained material. The microhardness increased with the increasing number of equal channel angular pressing passes. The Young modulus was measured by the methods of resonant ultrasound spectroscopy and also increased with the number of equal channel angular pressing passes. Significant increment of elastic modulus can be attributed to the formation omega-phase particles.