| 摘要 |
PURPOSE:To develop a clad material made of a high strength superplastic Al alloy excellent in corrosion resistance by cladding the core material made of an Al-Zn-Mg-Cu alloy having a specified compsn. with the surface material of an Al-Zn alloy under specified temp. conditions. CONSTITUTION:The ingot of the Al alloy contg., as essential components, by weight, 3 to 8% Zn, 1 to 3% Mg and 1 to 3% Cu and furthermore contg. one or >= two kinds among 0.05 to 1.0% Mn, 0.05 to 0.5% Cr, 0.05 to 0.5% Zr and <0.10% Ti is subjected to homogenizing heat treatment at 400 to 550 deg.C and is thereafter subjected to hot rolling into the lamellar core material having <=25mum grain size, and the sheet material of the Al-Zn alloy contg., as essential components, 0.8 to 1.3% Zn is formed into the surface material, and they are formed into a clad material in which the cladding ratio is regulated to 2 to 4% per single face, which is subjected to hot cladding rolling at 300 to 500 deg.C into the clad material. This clad material is subjected to annealing by holding under heating of two stages at 350 to 550 deg.C, is cooled at >=100 deg.C/hr cooling rate, is thereafter subjected to cold rolling of at least >=50% and is heated to 400 to 550 deg.C at >=500 deg.C/hr temp. raising rate. |
