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pISSN : 1598-706X / eISSN : 2288-8381


한국주조공학회지 (10권4호 332-341)

Effect of Solidification Conditions and Heat Treatment on the Mechanical Properties of the Al-CuAl_2 Eutectic Composite

Al-CuAl_2 공정복합재료의 기계적 성질에 미치는 응고조건과 열처리의 영향

Hyun-Kyu Lee*, Ju-Hong Lee**, Jong-Hwi Hong***

*Chosun univ., **Korea Univ., ***Korea Univ.


The structure and tensile properties of the unidirectionally solidified Al-33wt.%Cu alloy have been investigated. Casted Al-33wt.%Cu alloy was unidirectionally solidified with rates (R) between 1㎝/hr and 24cm/hr maintaining the thermal gradient(G) at solid-liquid interface, 32℃/cm and 21℃/cm. The entectic struture was varied according to the growth condition(G/R radio). When G/R ratio was larger than 8.5x10^3℃/cm^2/sec the lamellar structure was formed, and colony structure was formed when G/R ratio was smaller than 8.5x10^3℃/cm^2/sec. The interlamellar spacing(γ) in the above alloy system was vaired with the growth rate(R) According to "γ^2'R=8.8x10^{-11}cm^2/sec" relationship. The yield stress (∑0.001) and UTS for samples in the as-grown condition increased with the interlamellar spacing decrease and the values corresponding to colony structure are lower than those corresponding to amellar structure with the same lamellar spacing. The yield stress for samples in aged condition did not change with the interlamellar spacing.