Stress-assisted transformation in Ti-60 wt pct Ta alloys

作     者：Margevicius, RW Cotton, JD 

作者机构：Materials Science and Technology Los Alamos National Laboratory 87545 Los Alamos NM Present address: Los Alamos National Laboratory USA Boeing Information Space and Defense Systems 98124-2499 Seattle WA 

出 版 物：《METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE》 (冶金学与材料汇刊A辑：物理冶金学与材料科学)

年 卷 期：1998年第29卷第1期

页      面：139-147页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

主　　题：Titanium alloys 

摘      要：An investigation of the influence of processing variables on mechanical properties and phase development for a Ti-60 wt pet Ta (Ti-28.5 at. pet Ta) alloy was conducted. The alloy was hot-rolled, subjected to heat-treatment temperatures above the beta (bcc) transus (I hour at 700 degrees C, 800 degrees C, or 900 degrees C), and water quenched. All heat treatments produced a combination of metastable beta (bcc) and metastable alpha (orthorhombic martensite), with the amount of retained beta essentially independent of heat treatment, ranging from 20 to 33 vol pet. 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 -- alpha martensitic transformation. The stress required to initiate the transformation increased with pre-quench 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.