METHOD FOR MANUFACTURING OF AL-ZN-MG-CU ALLOY SHEET WITH REFINED CRYSTAL GRAINS

摘要

The present invention relates to a method to manufacture an aluminum-zinc-magnesium-copper alloy sheet having refined crystal grains. More specifically, the present invention provides the method to manufacture the aluminum-zinc-magnesium-copper alloy sheet having refined crystal grains, comprising: (step 1) a step of manufacturing an aluminum alloy sheet using a molten aluminum-zinc-magnesium-copper alloy by a twin roll strip casting process; (step 2) primarily rolling the aluminum alloy sheet manufactured in step 1; (step 3) cold-rolling the aluminum alloy sheet manufactured in step 2; and (step 4) heat-treating the aluminum alloy sheet manufactured in step 3. According to the present invention, the aluminum-zinc-magnesium-copper alloy sheet is manufactured by utilizing a twin roll casting process, thus reducing processing time and costs. Additionally, as the sheet manufactured by the twin roll casting process is hot-rolled and cold-rolled in order and heat-treated; refinement and homogenization of crystal grains of the sheet can be maximized, thus improving elongation. Moreover, the aluminum sheet manufactured by the method is significantly improved in terms of balance between strength and ductility including elongation such that the aluminum sheet is able to usefully be utilized for components of a light transfer machine and structural materials.