[1] Singer A R E. Met Mater, 1970; 4: 246 [2] Evans R, Leatham A G, Brooks R G. Powder Metall, 1985;28: 13 [3] Leatham A G, In: Osprey Metals Ltd ed., Second Int ConOn SF. Swansea, UK, 1993: 129 [4] Higginbotham G J S, In: Osprey Metals Ltd ed., SecondInter Con on SF. Swansea, UK, 1993: 259 [5] Lee S, Claus S. Int J Powder Metall. 1997; 3: 31 [6] Seok H K, In: Osprey Metals Ltd ed., Third Int Con On SFCardiff, UK, 1996: 287 [7] Mathur P, Apelian D, Lawley A. Acta Metall, 1989; 37: 429 [8] Ando T, Tsao C Y. Int J Powder Metall, 1990; 4: 311j