Page 278 - Fiber Fracture

FRACTURE OF SUPERFINE METALLIC WIRES 26 1

(3) If the die half-angle is too large or the reduction/pass is too small, an internal
fracture or core and filament breaks are liable to occur, which has been confirmed by
simulation and experiment.
(4) The FEA simulation revealed that high tensile stress is applied to the core of
a wire under the conditions under which filament breaks are likely to occur. For this
reason, to prevent filament breaks, brittle superconducting filaments should not be
placed at the center of a wire.
(5) Filament breaks of a single-filament wire during drawing can be detected by
AE. AE motoring is effective and informative for the detection of internal fractures and
filament breaks.

ACKNOWLEDGEMENTS

The author would like to thank the many members of the drawing committee in Japan
for valuable discussions and is also grateful to Mr. M. Arashida at Daiichidenko K.K
and Mr. K. Maeda at NIHON-ESI K.K. for his helpful comments, and to SEIKO Corp.,
Mr. C. Raskin at Union Miniere Copper, and the Japan Railway Technical Research
Institute for giving the precious photographs.

REFERENCES

Arashida, M. et al. (1994) Oprec Rev. (in Japanese). Daiichi-Lknko, Japan, 5, pp. 8-1 I.
Avitzur, B. ( 1968). Trans. ASME, Ser: B, 90: 79-9 1.
Chen, C.C., Oh, S.I. and Kobayashi, S. (1979). Trans. ASME Ser: B, 101: 23-44.
Chia, E.H. and Jackson, P.M. (1978) Wire J. Int., December, 56-60.
Coffin, L.F. and Roger, H.C. (1967). Trans. ASM, 60 672-686.
Ikeda, T. et al. (1988) Proceedings of the 27th Japanese Conference for Wire Drawing. Drawing Committee.
Japan Society for Technology of Plasticity, Japan.
Jennison, H.C. (1930). Trans. AIME, 89: 121-139.
Nakamura, N. and Wada, T. (1980) The Cooper Story (in Japanese). Nihon-doh-senta, Tokyo, pp. 250-258.
Nishioka, T. (1956). J. Jpn. Inst. Met., 20 181-184.
Raskin, C. (1 997) Proceedings of the WAI International Technical Conference, Italy.
Raskin, C. and Janssen, J. (1998) Wire J. Int., 31( 12): 80-86.
Remmer, W.E. (I 93O)Proc. Inst. Met., pp. 107- 120.
su, Y.Y. (1982) wire J. In?., January, 74-79.
Tanaka. H. and Yoshida, K. (1979). J. Jpn. Inst. Mer., 43: 618-625.
Tanaka, H. and Yoshida, K. (1983). J. Jpn. Soc. Technol. Plast., 24: 737-743.
Tanaka, H. et al. (1976). Furuhwadenkou-Jihou, 59: 91-98.
Tanaka. H. (1952). J. Jpn. Inst. Met., 16: 567-571.
Tanimoto, Y. (1998) In: Proceedings of the 181~1 Japanese Seminar for the Technology of Plasticir?;.
pp. 67-75. Japan Society for Technology of Plasticity, Japan.
Togashi, J. et al. (1979). Furukawadenkou-Jihou, Furukawa-Denko, Japan. 66, pp. 26-33.
Yoshida. K. (1982) Doctor dissertation at Tokai University. Tokai University, Tokyo.
Yoshida, K. (2000a). J. Jpn. Soc. Technol. Plasr.. 41: 194-198.
Yoshida, K. (2000b) Wire J. lnt., March, 102-107.
Yoshida, K. and Tanaka, H. (1987) Advanced Technology of Plasriciy II. Springer, Berlin, pp. 857-862.
Yoshida, K.. Sato, M. and Sekino, M. (1994) J. Jpn. Copper Brass Res. Assoc., 33: 212-218.