Stress-assisted transformation in Ti-60 wt pct Ta alloys
- Los Alamos National Lab., NM (United States)
An investigation of the influence of processing variables on mechanical properties and phase development for a Ti-60 wt pct Ta (Ti-28.5 at. pct Ta) alloy was conducted. The alloy was hot-rolled, subjected to heat-treatment temperatures above the {beta} (bcc) transus (1 hour at 700 C, 800 C, or 900 C), and water quenched. All heat treatments produced a combination of metastable {beta} (bcc) and metastable {alpha}{double_prime} (orthorhombic martensite), with the amount of retained {beta} essentially independent of heat treatment, ranging from 20 to 33 vol pct. Deformation of as-rolled and heat-treated tension specimens showed an anomalous leveling of the stress-strain curve in the stress-strain curves at low strains. X-ray diffraction (both simple 2{theta} diffractometry and texture analysis) on both deformed and undeformed material determined that the leveling of the stress-strain curve was a result of the {beta} {yields} {alpha}{double_prime} martensitic transformation. The stress required to initiate the transformation increased with prequench temperature. This was determined to be due to the presence of athermal {omega}. Grain growth kinetics have been determined in the course of this work.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 605817
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 1 Vol. 29; ISSN 1073-5623; ISSN MMTAEB
- Country of Publication:
- United States
- Language:
- English
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