Work hardening of microwave sintered blended elemental Ti alloys

Cost reduction of Ti alloys is paramount to open up new industrial opportunities and the powder metallurgy blended elemental approach is ideal for such endeavour. Although faster, microwave sintering is a pressureless sintering process and leaves behind residual porosity which lowers the mechanical performance limiting the applicability of the material. Work hardening and porosity sealing of microwave sintered blended elemental Ti alloys via thermomechanical deformation by means of hot extrusion in the β field was thus investigated. As expected, the chemistry and the thermal history of each alloy considered (i.e. pure Ti, Ti-6Al-4V, and Ti-5Fe) has an influence on the microstructure and mechanical performance. However, regardless of those two aspects, hot extrusion permits to obtain fully dense materials with enhanced mechanical behaviour due to the reduction of the residual pores and microstructural modification such as formation of lamellar substructures resulting in alloys with better strength/ductility pairings and, therefore, different strain hardening rates and deformation modes. © 2020 Elsevier B.V.