1. 1) K. Yamaguchi and Y. Takeda: Metallurgical Review of MMIJ, 15 (1998), 26.
2. 2) S. E. Amara, A. Belhadj, R. Kesri and S. H. Thibault: Zeitschrift für Metallkunde, 90 (1999), 116.
3. 3) K. Marukawa, T. Tanaka and S. Hara: Engineering Materials, 43 (2000), 62.
4. 4) M. Yamaguchi and T. Takeda: JPN Published Patent Application, P2004-83962A, (2004).
5. 5) T. Yoshida, S. Ueda and K. Yamaguchi: CAMP-ISIJ, 17 (2004), P3.