| In this study, Al-1%Si alloy for bonding wire was fabricated by the upward directional continuous casting process employing a heating mold above melt temperature. Effects of cold drawing and softening heat treatment on microstructure and properties of Al-1%Si alloy were investigated. The macrosegregation of Si particle in the directionally solidified Al-Si alloy significantly reduced comparing with the conventionally solidified alloy. As the cold drawing ratio increased, tensile strength increased and elongation decreased up to the drawing ratio of 99%, partially due to strain hardening and partially due to refinement of Si particles. The tensile fracture mode of the drawn specimen up to 95% was ductile fracture. The softening heat treatment below 200℃ did not affect the tensile properties. It was found, however, that the tensile strength decreased and elongation increased with increasing the softening heat treatment temperature above the recrystallization temperature between 200℃ and 350℃. The electrical resistivity showed increasing tendency with cold drawing and decreasing tendency with softening heat treatment. |
|
