Hostname: page-component-8448b6f56d-dnltx Total loading time: 0 Render date: 2024-04-16T04:49:04.367Z Has data issue: false hasContentIssue false

Effect of Heat Treatments on Microstructure of Rapidly Solidified TiCo Ribbons

Published online by Cambridge University Press:  26 February 2011

Kyosuke Yoshimi
Affiliation:
Institute for Materials Research, Tohoku University, Sendai, Miyagi 980–8577, JAPAN
Akira Yamauchi
Affiliation:
Institute for Materials Research, Tohoku University, Sendai, Miyagi 980–8577, JAPAN
Ryusuke Nakamura
Affiliation:
Institute for Materials Research, Tohoku University, Sendai, Miyagi 980–8577, JAPAN
Sadahiro Tsurekawa
Affiliation:
Department of Nanomechanics, Tohoku University, Sendai, Miyagi 980–8579, JAPAN
Shuji Hanada
Affiliation:
Institute for Materials Research, Tohoku University, Sendai, Miyagi 980–8577, JAPAN
Get access

Abstract

The effect of heat treatments (aging or annealing) on microstructure was investigated for rapidly solidified ribbons of near-stoichiometric TiCo. In as-spun ribbons, it was observed by TEM that an equiaxed grain structure was developed and its crystal structure had been already B2-ordered, while a small amount of a second phase, Ti2Co, finely disperses in grains and along grain boundaries. Some grains were dislocation-free but others contained curved or helical dislocations and prismatic loops having a Burgers vector parallel to <100> directions. By annealing the as-spun ribbons at 700°C for 24h, the dislocation density was obviously increased compared with that of the as-spun ribbons, while grain growth appears to occur slightly. The increase of the dislocation density in the annealed ribbons is believed to result from the condensation and/or absorption of supersaturated vacancies. Therefore, the TEM observation results indicate that a large amount of supersaturated thermal vacancies were retained in the TiCo ribbons by the rapid solidification.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Yoshimi, K., Hanada, S., Haraguchi, T., Kato, H., Itoi, T. and Inoue, A., Mater. Trans. 43, 2897 (2002).Google Scholar
2. Würschum, R., Grupp, C. and Schaefer, H.-E., Phys. Rev. Lett. 75, 97 (1995).Google Scholar
3. Fu, C.L., Ye, Y.Y., Yoo, M.H. and Ho, K.M., Phys. Rev. B 48, 6712 (1993).Google Scholar
4. Takasugi, T. and Izumi, O., Phys. Stat. Sol. (a) 102, 697 (1987).Google Scholar
5. Vitta, S., Metall. Trans. A 24A, 1869 (1993).Google Scholar
6. Wittmann, M. and Baker, I., Mater. Sci. Eng. A A329–331, 206 (2002).Google Scholar
7. Zaroual, S., Sassi, O., Aride, J., Bernardini, J. and Moya, G., Mater. Sci. Eng. A A279, 282 (2000).Google Scholar