한국주조공학회

The structures and mechanical property of the unidirectionally solidified A1-Co eutectic alloy were investigated. Al-Co eutectic alloy was unidirectionally solidified with growth rates(R) between 1 cm/hr and 10 cm/hr in the induction furnace maintaining the thennal gradient (G) at solid-liquid interface, 32°C/cm. The eutectic rnicrostructure was varied with the growth condition(G/R ratio). When the G/R ratio was larger than 8.5 >< 103°C/cmz/sec, a lamellar structure was formed, But the G/R ratio was smaller than 8.5 X 103°C/cmz/sec, a colony structure was formed. It was found that the interlamellar spacing(7t) was dependent on the growth rate(R) with the relationship, 12- Rzconstant. The rnicrohardness of this eutectic alloy increased with increase in the growth rate

Solid-liquid interface, Colony structure, Thermal gradient