J. Phys. IV France
Volume 112, October 2003
Page(s) 1035 - 1038

J. Phys. IV France
112 (2003) 1035
DOI: 10.1051/jp4:20031058

Martensitic transformation in Ti 50Pd 50.0-XFe X alloy

S. li1, M. Nishida1, Y. Murakami1 and D. Shindo2

1  Kumamoto University, Graduate School of Science and Technology, 2-39-1 Kurokami, Kumamoto 860-8555, Japan
2  Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan

In order to clarify the transformation sequence in Ti 50.0Pd $_{50.0-\rm X}$Fe $_{\rm X}$ alloy in detail, in-situ heating TEM observations and electron diffraction experiments were carried out in JEM-2010 microscope equipped with omega type energy-filter. Mf temperature of Ti 50.0Pd 43.0Fe 7.0 alloy is about 520 K and martensite of 2H and 9R structures are observed at room temperature. The 9R martensite directly reverts to the B2 parent phase via no intermediate state. Only incommensurate (IC) phase is confirmed at room temperature in Ti 50.0Pd 40.0Fe 10.0 and Ti 50.0Pd 36.0Fe l4.0 alloys, although Mf temperatures ofthese alloys are above room temperature. The IC phase transforms to the B2 parent phase without any shift of intensity maximum position of IC reflections with heating. Therefore, the low temperature phase in the alloys with more than 8.0 at % of Fe is the IC phase. Based on these results, systematical transformation phase diagram is proposed.

© EDP Sciences 2003