Abstract
Ti-matrix composites reinforced with Al₂O₃ fractions of up to 50 wt.% were fabricated by cold consolidation of powder mixtures using high-pressure torsion (HPT). The grain size of the Ti matrix was reduced to ≈100 nm. A relative density greater than ≈99 % was attained for composites containing up to 30 % Al₂O₃ following the rule of mixture. The Vickers microhardness increased with an increase in the Al₂O₃ fraction but the bending stress and ductility decreased. The HPT-processed composites exhibited an abrupt increase in the hardness when they were annealed at 800-900 K, indicating a successful achievement of consolidation.

Key words
titanium, Ti-matrix composite, ultrafine grain, high-pressure torsion, severe plastic deformation, consolidation

Full text (507 KB)