1. A. W. Kirby and D. J. Fray, Met. Trans. 20B (1989) 219.
2. Idem, Trans. IMM 98 (1989) C33.
3. Idem, ibid 98 (1989) C89.
4. Idem, ibid 98 (1989) C96.
5. J. A. Sommers, J. R. Peterson, T. R. Mcqueary and M. A. Rossback, J. Metals 43 (11) (1991) C109 (abstr).