Open Access
Article Number 05011
Number of page(s) 7
Section Applied Research and Applications: Engineering Materials with MT
Published online 01 September 2009
ESOMAT 2009, 05011 (2009)
DOI: 10.1051/esomat/200905011

Microhardness of binary near-equiatomic Ti-Ni alloys after severe cold rolling and post-deformation annealing

K. Inaekyan1, V. Brailovski1, S. Prokoshkin2, A. Korotitskiy2 and A. Chernavina2

1  Ecole de Technologie Superieure, 1100, Notre-Dame Street West, Montreal, H3C 1K3, Canada
2  Moscow Institute of Steel and Alloys, 4, Leninsky prosp., Moscow 119049, Russia

Published online: 1 September 2009

Comparative HV-microhardness and TEM studies of Ti-50.0at%Ni and 50.26at%Ni alloys subjected to cold-rolling (e=0.3, 1 and 1.72) and post-deformation annealing at 100-700°C (1 hour) are presented. Based on the TEM-measured grain size data for Ti-50.0at%Ni alloy as a function of an annealing temperature (TPDA) higher than 250°C, it was possible to evaluate the grain size (d) of the near-equiatomic Ti-Ni alloys at TPDA<250°C, using exponential extrapolation distribution of the d-TPDA data. It was shown that below a critical grain size (dc = 10 nm), the smaller the grain size (as a result of the decrease in annealing temperature), the lower the microhardness. This softening phenomena can be described, with good correlation between the approximation and experimental data, by the normal-abnormal Hall-Petch transition caused by the influence of the intercrystalline regions and by the melting temperature grain-size dependence.

Note to the reader:
On pages 05011-p3, 05011-p4 and 05011-p5 several mistakes have been corrected on October 19, 2009.

© Owned by the authors, published by EDP Sciences 2009