The present work focuses on the microstructural evolution and resulting room temperature mechanical properties of P/M Ti-6Al-4V severely deformed at different temperatures (550°C to 800°C) using Equal Channel Angular Extrusion (ECAE). The bulk materials are extruded through two channels of equal cross section intersecting an angle of 90 degree. Microstructure and mechanical properties of extruded billets are reported through electron microsopy observations and tension, compression and hardness experiments. Results are compared for different extrusion conditions including variations in temperature and processing route. Higher hardness values are obtained after ECAE compared to as-received values. These improvements are correlated with the grain refinement, phase refinement and texture produced during ECAE. The most favorable microstructure in terms of refined grains was two passes at 600°C. The ultimate goal is to develop ECAE thermomechanical-processing maps for the selection of processing schedules to obtain desired end microstructures and improved fatigue life in Ti-Al-V based materials. The investigations revealed that: 1. ECAE shear deformation leads to refinement in β plates and elimination of piror β boundaries. Decreasing extrusion temperature and increasing number of passes decreases α plate size and grain size. Refined α grain size leads to a significant increase in tensile and compressive flow stresses at room temperature. 2. The second extrusion pass at 800°C increased both the yield strength and ductility. This was attributed to the observed α plate refinement. 3. Cavitation at the interface between β strips and α plates at 550°C was thought to be the reason for low ductility and relatively low strain hardening at room temperature. 4. Texture has a pronounced effect on mechanical properties. Tension/compression asymmetry in flow strengths and strain hardening coefficients may be described by the activation of differing slip systems under tension and compression loading because of texture.

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