| Title |
Homgenization of Direct Chill Casted Al-10 wt.%Si-2 wt.% Cu-1 wt.% Mg-0.5 wt.% Mn Alloy |
| Authors |
장준연(Joon Yeon Chang),고흥석(Heung Seok Ko),유재은(Jae Eun Yoo),신동혁(Dong Hyuk Shin) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
Microstructure of a direct chill casted Al-10 wt.%Bi-2 wt.%Cu-1 wt.%Mg-0.5 wt.%Mn alloy φ180×2000 ㎜ in size was carefully investigated on the subsequent process after casting in order to search the optimum process condition suitable for mass production. Both the chemical modification by adding Sr into the melt and the rapid cooling rate by employing direct chill easting result in homogeneous cast structure consisting of primary Al and modified fine eutectic Si in spite of a large size of the ingot. The formation of ternary eutectics leads the segregation of CuMgAl₂ phase mainly in the center of the ingot. DSC reveals that ternary eutectics dissolves into the matrix around 520℃. The separation of network-structured fibrous eutectic Si to fine particle is found after one-hour heating above 460℃. Proper heat treatment causes equiaxed fine Si particle with the size of 10 ㎛ and complete dissolution of segregated CuMgAl₂ phase. Coarsening of separated Si particle is governed by diffusion controlled growth. |