Effect of Wheel Speed on Transformation Charcteristics in Rapidly Solidified Fe-Mn-Si Based SMA Ribbons
|W. Y. Jang 2, Kwang K. Jee 1, J. W. Kang 2, W. S. Jo 2|
1. Korea Institute of Science and Technology, Material Science and Engineering Division, Seoul, Korea, South
Effects of colling rate and annealing temperature on the microstructure and grain size have been investigated in Fe-Mn-Si based SMA Ribbons, and the correlation between those intrinsic factors and martensitic transformation characteristics has been discussed.
When Fe-Mn-Si based SMA ribbons were fabricated by RSP, grain size of the ribbon was refined up to 4 ㎛ and the uniformity of grains were improved by increasing wheel speed i.e cooling rate. The volume fraction of thermal ε martensite was increased by increasing colling rate.
Refined grains of the melt-spin ribbon were partially grown by annealing above 300℃×3min. By increasing annealing temperature, the volume fraction of thermal ε martensite was increased and that of α′martensite were also highly increased in the resultant ribbons. Ms temperature of annealed ribbon was higher than that of as-spun ribbon and transformation temperature hysteresis(Af-Ms) was decreased by increasing annealing temperature.
Presentation: poster at E-MRS Fall Meeting 2005, Symposium C, by W. Y. Jang
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-05-20 14:04 Revised: 2009-06-07 00:44