日本金属学会誌

J. Japan Inst. Metals, Vol. 59, No. 8 (1995),
pp. 780-787

Deformation Induced Transformation of ω Phase in Aged Ti-14 mass%Mo Alloy

Yoshito Takemoto, Moritaka Hida and Akira Sakakibara

Department of Mechanics, Faculty of Engineering, Okayama University, Okayama

Abstract:

Ti-14 mass%Mo alloys aged for 1{×}106 s at 623 K were deformed by means of a tensile test at 300, 523, 623 and 723 K in Ar atmosphere or of rolling at room temperature in order to investigate the brittle fracture mechanism related to the ω phase. These deformed specimens were observed by optical and transmission electron microscopy. Both deformed structures consisted of many band-like products. In the products, very few ω particles could be found. Instead, zones having a structure different from ω, β and α phases existed. It was found that these zones possessed a body centered triclinic structure, which was newly named β′′ on account of the structural similarity to the β phase. The β′′ was transformed from ω by deformation. In the transformation process to β′′, one ω variant changed into two types of β′′; one was closely related to the β matrix, and the other had a {112}<{111}> twin relation to the former. It is suggested that the band products act as a path of crack propagation prior to the brittle fracture in the aged Ti-Mo alloy.


(Received February 6, 1995)

Keywords:

titanium-molybdenum alloy, aging, ω-phase, deformation induced transformation, martensite, brittle fracture, twin relation


PDF(Free)PDF (Free)     Table of ContentsTable of Contents

Please do not copy without permission.