Recycled Material-Containing 7000 Series Aluminum Alloy, Billet And Extruded Material Using The Same, And Method Of Manufacturing Extruded Material

Abstract

A recycled material-containing 7000 series aluminum alloy including, by mass %, 6.0 to 8.0% of Zn, 1.0 to 2.0% of Mg, 0.10 to 1.0% of Cu, 0.004 to 0.40% of Mn, 0.10 to 0.25% of Zr, 0.005 to 0.05% of Ti, and 0.05% or less of Cr, wherein 30% or more of recycled material is contained with content ranges of Si and Fe set as ranges of 0.01 to 0.25% of Si, 0.10 to 0.40% of Fe, and 0.20 to 1.05% of [Fe+Mn+Zr].

1 . A recycled material-containing 7000 series aluminum alloy comprising, by mass %, 6.0 to 8.0% of Zn, 1.0 to 2.0% of Mg, 0.10 to 1.0% of Cu, 0.004 to 0.40% of Mn, 0.10 to 0.25% of Zr, 0.005 to 0.05% of Ti, and 0.05% or less of Cr, wherein 30% or more of recycled material is contained with content ranges of Si and Fe set as ranges of 0.01 to 0.25% of Si, 0.10 to 0.40% of Fe, and 0.20 to 1.05% of [Fe+Mn+Zr]. 
     
     
         2 . An extrusion processing billet cast by using the 7000 series aluminum alloy according to  claim 1 ,
 wherein in the billet, an average length of crystallized substances in a metal texture is 100 μm or less, and a crystallized substance ratio is 6% or less.   
     
     
         3 . An aluminum alloy extruded material obtained by using the extrusion processing billet according to  claim 2 , wherein in the extruded material, an average length of crystallized substances in a metal texture is 20 μm or less, and a crystallized substance ratio is 6% or less. 
     
     
         4 . A method of manufacturing an extruded material, wherein by using the 7000 series aluminum alloy according to  claim 1 , a billet having a diameter of 174 mm or more is cast at a casting rate of 45 mm/min or more and a solidification rate during casting of 5° C./sec or more, and extrusion processing is performed under a condition that an extrusion ratio is 12 or more by using the cast billet.