日本金属学会誌

J. Japan Inst. Metals, Vol. 63, No. 9 (1999),
pp. 1218-1223

Crystallization Process of Amorphous Phase Produced by Ion Irradiationin TiNi Shape Memory Alloy

Yutaka Sumida, Yoshitaka Matsukawa,Yasuyuki Haishi and Somei Ohnuki

Division of Material Engineering, Graduate School of Engineering, Hokkaido University, Sapporo

Abstract:

Thermal crystallization from amorphous TiNi has been investigated due to ``in-situ'' observation in a high voltage electron microscope. The specimens contained several types of nucleation sites, such as free surfaces, C--A interfaces and cracks, which enabled to comparing crystallization at each site. The heterogeneous nucleation developed at the specimen edge and the crystalline-amorphous interface, where the crystallization temperature depended on each nucleation sites. The crystal growth was liner relation at each temperature, and the activation energy from Arrhenius plot was evaluated as 2.7 eV. The preferential crystallization was observed also on pre-cracked area, which implies some stress-assisted effect on the crystallization.


(Received February 25, 1999; In Final Form July 13, 1999)

Keywords:

TiNi, crystallization, amorphous, irradiation, in-situ observation, crystallization temperature


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

Please do not copy without permission.