1. 1) K. Nagata and K. S. Goto: Met. Trans., 5 (1974), 899.
2. 2) W. L. Worrell, V. B. Tare and F. J. Bruni: High Temperature Technology, Proceedings of the Third International Symposium, held in Asilomar, California, (1967), 503; International Union of Pure and Applied Chemistry, Butterworths, London.
3. 3) H. Nakamura and K. Gunji: J. Japan Inst. Metals, 42 (1978), 635;
4. Trans. JIM, 21 (1980), 375.
5. 4) A. Egami, T. Onoye and K. Narita: Trans. JIM, 22 (1981), 399.