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Structure and Recalescence Behavior of Underctoled Nickel-Tin Alloys

Published online by Cambridge University Press:  21 February 2011

Yanzhong WU
Affiliation:
Massachusetts Institute of Technolocy, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
Thomas J. Piccone
Affiliation:
Massachusetts Institute of Technolocy, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
Yuh Shiohara
Affiliation:
Massachusetts Institute of Technolocy, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
Merton C. Flemings
Affiliation:
Massachusetts Institute of Technolocy, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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Abstract

Small nickel-tin alloy samples (3.2 g) were bulk undercooled in a Pyrex-brand borosilicate glass medium using a levitation melter. Recalescence was directly observed utilizinq a rapid thermal measurement system (resnonse time less than 10 us) consisting of two silicon photodiodes, signal amplification system, and a digital storarie device.

Results of this research include: (1) measured undercoolings ranqed up to about 250 K; (2) both total solidification time and recalescence time become shorter with increasing initial undercooling; (3) in the case of hypoeutectic (Ni-25wt%Sn) alloy, a range of recalescence times was observed from 500 ms for a low undercooling (about 35 K) to 2 ms for a hiqh undercooling (about 230 K); (4) thermal profiles upon solidification of hypoeutectic comnosition alloys showed the existence of two distinct nucleation events; (5) although cooling rates before nucleation were generally low (<50 K/s), structures of fineness expected in rapid solidification processing were typically observed; (6) fineness of microstructure increases with increasing undercooling; and (7) uniform distribution of second phase was achieved by increasing undercoolina.

Type
Research Article
Copyright
Copyright © Materials Research Society 1984

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References

REFERENCES

1. Colligan, G.E. and Bayles, B.J., Acta Met. 10, 895897 (1962).10.1016/0001-6160(62)90107-4Google Scholar
2. Huang, S.C. and Glicksman, M.E., Acta Met. 29, 701715 (1981).10.1016/0001-6160(81)90115-2Google Scholar
3. Kobayashi, K. and Shingu, H.P., Proceedings of the 4th International Conference on Rapidly Quenched Metals, Masumoto, T. and Suzuki, K. (Eds.) Sendai, Japan, 103106 (1981).Google Scholar
4. Coriell, S.R. and Turnbull, D., Acta Met. 30, 21352139 (1982).10.1016/0001-6160(82)90134-1Google Scholar
5. Flemings, M.C. and Shiohara, Y., Soecial Issue of Materials Science and Engineering: “Solidification Microstructure: Thirty Years After Constitutional Supercooling,” Jones, H. and Kurz, W. (Eds.), to be published.Google Scholar
6. Baker, J.C. and Cahn, J. W., “Solidification,” ASM, 23 – 58 (1971).Google Scholar
7. Shiohara, Y., Chu, M.G., and Fleminqs, M.C., Proceedings of the US/Japan Cooperative Science Program Seminar on “Solidification Processing,” Dedham, MA, Flemings, M.C. and Ohira, G. (Eds.), 375 – 402 (1983).Google Scholar
8. Aziz, M.J., J. Appl. Phys. 53, 11581168 (1982).10.1063/1.329867Google Scholar
9. Baker, J.C., Ph.D. Dissertation, Massachusetts Institute of Technology, (1970).Google Scholar
10. Shiohara, Y. and Flemings, H.C., Proceedings of the 2nd Conference on “Modeling of Casting and Weldina Processes,” Henniker, NH, August (1983), in press.Google Scholar
11. Flemings, M.C., “Solidification Processing,” McGraw-Hill, NY, NY (1974).10.1007/BF02643923Google Scholar
12. Kattamis, T.Z., Coughlin, J.M., and Flemings, M.C., Trans. AIME 239, 15041511 (1967).Google Scholar
13. Vorhees, P.W. and Glicksman, M.E., Proceedings of MRS Conference on “Rapidly Solidified Amornhouse and Crystalline Alloys,” Kear, B.H., Giessen, B.C., and Cohen, M. (Eds.), North Holland, 33 – 47 (1982).Google Scholar