J. Phys. IV France 11 (2001) Pr8-75-Pr8-79
30 MHz ultrasonic attenuation of TiNi single crystal associated with B2-B19' martensitic transformation and twin boundariesX. Ren1, X.L. Liang2, K. Otsuka3, T. Suzuki4, H.M. Shen2 and Y.N. Wang2
1 Materials Physics Group, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan
2 Department of Physics, Nanjing University, Nanjing, China
3 Smart Structure Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
4 Tsukuba Institute of Science and Technology, Tsukuba, Japan
Ultrasonic attenuation was measured for the first time at megahertz range (30MHz) for a TiNi single crystal, which undergoes B2-B19' (cubic-monoclinic) martensitic transformation. A sharp attenuation peak was found at transformation temperature region (two-phase region), which was associated with the structural transformation and drastic domain wall evolution in the two-phase region. Besides, a very broad peak below the transformation temperature (i.e., in martensite state) was also found, which can be ascribed to twin boundary motion at megahertz range. This broad peak has a high internal friction level of 0.0027. Considering that this alloy also has a high damping capacity at low frequency, we can deduce that TiNi martensite is an excellent high damping material in an extremely wide frequency range and wide temperature range.
© EDP Sciences 2001