Method of manufacturing aluminum-zinc-based alloy sheet using twin-roll casting and aluminum-zinc-based alloy sheet manufactured thereby
Provided are a method of manufacturing an aluminum-zinc-based alloy sheet using twin-roll casting and an aluminum-zinc-based alloy sheet manufactured thereby. Specifically, a method of manufacturing an aluminum-zinc-based alloy sheet, including preparing a melt by melting elements corresponding to an aluminum alloy including 0.5 wt % to 10 wt % of zinc, inevitable impurities and aluminum as a balance (step 1); and twin-roll casting by introducing the melt prepared in step 1 between a pair of rotating cooling rolls (step 2), and an aluminum-zinc-based alloy sheet manufactured thereby are provided. The present invention may manufacture an aluminum-zinc-based alloy sheet, in which twin-roll casting is known to be difficult due to a wide solid-liquid coexistence region, by twin-roll casting by using cooling rolls having high thermal conductivity and controlling a reduction force by the rotational speed of the rolls.
1. A method of manufacturing an aluminum-zinc-based alloy sheet, the method comprising:
preparing a melt by melting elements corresponding to an aluminum alloy including 1 wt % to 6 wt % of zinc, 0.5 wt % to 5 wt % of magnesium and 0.05 wt % to 3 wt % of copper, inevitable impurities and aluminum as a balance (step 1); and
twin-roll casting by introducing the melt prepared in step 1 between a pair of rotating cooling rolls (step 2),
wherein the twin-roll casting in step 2 is performed under a condition of a reduction force of 10 kg/mm to 100 kg/mm, wherein the cooling roll of step 2 is a copper alloy roll or a copper roll, and wherein a gap is present between the cooling rolls of step 2 in a range of 2 mm to 10 mm.
2. The method as set forth in claim 1 , wherein the copper alloy is copper (Cu)-chromium (Cr) or Cu-beryllium (Be).
3. The method as set forth in claim 1 , wherein the melt of step 1 further comprises 0.005 wt % to 0.2 wt % of titanium.
4. The method as set forth in claim 1 , wherein the melt of step 1 further comprises 0.01 wt % to 0.3 wt % of zirconium.
5. The method as set forth in claim 1 , wherein the melt of step 1 further comprises 0.01 wt % to 0.3 wt % of chromium.
6. The method as set forth in claim 1 , wherein the cooling rolls of step 2 comprise a water cooling hole.
7. The method as set forth in claim 1 , wherein the twin-roll casting in step 2 is performed under a condition of a reduction force of 40 kg/mm to 55 kg/mm.