Study on Grain Refinement Mechanisms and Mechanical Properties of bi-Modal Ti-55511 Titanium Alloy during Hot Rolling.

ABSTRACT: Multi-pass hot rolling was performed on bi-modal Ti-55511 alloy with 50% rolling reduction at 700 °C. Mechanical properties were evaluated by tensile test, and microstructure evolution was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that the Ti-55511 alloy with bi-modal microstructure exhibits good strength and high ductility (1102 MPa, 21.7%). Comparatively, after 50% hot rolling, an enhanced strength and decreased ductility were obtained. The refinement of ? phases leads to the increased tensile strength, while the fragmentation of the equiaxed ? phase results in a decreased ductility. The fragmentation process of equiaxed ? phases followed the sequence of: elongation of ? phases ? formation of grooves and localized shear bands ? the final fragmentation accomplished via deepening grooves.

SUBMITTER: Chen W 

PROVIDER: S-EPMC7435951 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature