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Indexed by:Journal Papers

Date of Publication:2019-10-24

Journal:MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

Included Journals:SCIE

Volume:766

Page Number:138363

ISSN No.:0921-5093

Key Words:Titanium alloy; Deformation temperature; {332} < 113 > twinning; Strain hardening behavior; Deformation microstructure

Abstract:The coupling effect of deformation mode and deformation temperature from 298 K to 673 K on tensile properties was systematically studied in a Ti-15Mo alloy with {332} < 113 > twinning-induced plasticity (TWIP) effect and a comparison material of Ti-15Mo-1Fe alloy deformed by dislocation slip. The yield strength remained relatively constant in Ti-15Mo alloy, while it monotonously decreased in Ti-15Mo-1Fe alloy as increasing deformation temperature. Due to enhancement of beta phase stability from omega phase precipitation, the {332} < 113 > twinning was suppressed and the contribution of dislocation slip to plastic deformation increased, which compensated the thermal softening effect in Ti-15Mo alloy. High strain hardening rate was induced in Ti-15Mo alloy at 298 K due to the dynamic Hall-Petch effect from amounts of {332} < 113 > twins and formation of abundant geometrically necessary dislocations (GNDs). As increasing deformation temperature, the suppression of dynamic Hall-Petch effect and GNDs formation as well as the enhancement of dynamic recovery rate of dislocations resulted in the continuous decrease in strain hardening rate.