TITLE:
Hot Rolling and Ageing Effect on the Pseudoelasticity Behaviour of Ti-Rich TiNi Shape Memory Alloy
AUTHORS:
Narendranath. S., Vijay Desai, S. Basavarajappa, K.V. Arun, S. Manjunath Yadav
KEYWORDS:
Pseudoelasticity; S M A; Critical stress; Elongation
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.9 No.4,
April
20,
2010
ABSTRACT: This paper presents the findings of an experimental study of how ageing temperature affects the
pseudoelasticity (PE) and its phases of Shape Memory Alloy (SMA). These have been examined
by means of tensile testing machine and X-ray diffraction (XRD). By increasing the ageing
temperature (constant ageing time) from 350oC to 550oC critical stress for martensite formation
and psuedo-elastic elongation increased. However, specimen aged at 650oC showed a decrease
in the critical stress for martensite formation and psuedo-elastic elongation. After second and
third sequence of loading and unloading, the critical stress shifted towards higher side was
observed. The XRD measurement revealed that phases present in the matrix drastically changes
with ageing temperatures. Transformation was taking place in two-way transformation, i.e.,
during heating martensite (B19') transformed to austenite (B2) while cooling the austenite (B2) transformed back to martensite (B19') .