| Title |
Improvement of High - Temperature Toughness by Crystallization - Induced Plasticity in Amorphous Al - Ni - Fe - Nd Alloys |
| Authors |
최갑송(Gab Song Choi) ; 김영환(Yeong Hwan Kim) ; 조현기(Hyun Kee Cho) |
| Abstract |
Microstructures, thermal stability and deformation characteristics of amorphous Al_(88)Ni_(10-x)Fe_xNd₂(x=0,3,5 at %) alloys were examined during tensile testing in the temperature range from room temperature to 680K. Three alloys experienced the two-stage crystallization process of Am→Am+Al→Al+compound at the temperature range. The particle sizes were about 10nm and 30-50nm for Al phase and the compound, respectively. The onset temperature of the precipitation for Al and intermetallic compound phases increased with the replacement of Ni by Fe, indicating an enhancement of thermal stability of the amorphous phase. All the amorphous alloys subjected to tensile testing at elevated temperature exhibited large elongations of 22-42% and 40-54% near precipitation peak temperature of Al and intermetallic compound phases, respectively. The large elongation is interpreted to be induced by crystallization of these phases. Tensile fracture occurred through shear slip of amorphous phase below T_(x2), respectively. |