| Title |
Addition of Rare Earth Metal in HypoeutecticAl-7.5wt.%Si Alloy |
| Authors |
장준연(J . Y . Chang) ; 박남규(N . K . Park) ; 고흥석(H . S . Ko) ; 문인기(I . G . Moon) ; 최종술(C . S . Choi) |
| Abstract |
The addition of RE elements in the form of misch metal is considerably effective in the modification of Al-7.5wt.%Si alloy. The morphology of eutectic Si was drastically changed from coarse flake to fine fibrous when RE was added. 1wt.% addition of RE appeared to be favorable to the modification of eutectic Si in terms of the size reduction of eutectic Si and the improvement of mechanical properties. Like Sr and Na, a decrease in the eutectic temperature was also found in RE-added alloy. Most of the RE participate in the formation of coarse intermetallic compounds and only a small quantity of RE solute still remaines in retained liquid phase. RE solute dissolved in liquid phase may affect the modification of eutectic phase by reducing the anisotropy and preventing the TPRE(twin plane re-entrant) growth of eutectic Si phase. |