Optimal Design of High-Strength Ti?Al?V?Zr Alloys through a Combinatorial Approach.

ABSTRACT: The influence of various Zr contents (0?45 wt.%) on the microstructure and mechanical properties of Ti6Al4V alloy was investigated through a combinatorial approach. The diffusion multiples of Ti6Al4V?Ti6Al4V20Fe?Ti6Al4V20Cr?Ti6Al4V20Mo?Ti6Al4V45Zr were manufactured and diffusion-annealed to obtain a large composition space. Scanning electron microscopy, electron probe micro-analysis, and a microhardness system were combined to determine the relationships among the composition, microstructure, and hardness of these alloys. The Ti?6Al?4V?30Zr alloy was found to contain the thinnest ? lath and showed peak hardness. X-ray diffraction and transmission electron microscope results indicated that after quenching from the ?-field, the metastable ??-phase formed; moreover, at the secondary aging stage, the metastable ??-phase acted as precursor nucleation sites for the stable ?-phase. The bulk Ti6Al4V30Zr alloy was manufactured. After aging at 550 °C, the alloy showed excellent balance of strength and ductility, and the tensile strength was 1464 MPa with a moderate elongation (8.3%). As the aging temperature increased, the tensile strength and yield strength of the alloys rose, but the total elongation decreased. The lamella thickness and volume fraction of the ?-phase were the major factors that had great impacts on the mechanical properties.

SUBMITTER: Wu D 

PROVIDER: S-EPMC6164444 | biostudies-other | 2018 Sep

REPOSITORIES: biostudies-other