摘要 |
The present invention relates to an aluminum alloy for the manufacture of thick blocks comprising (as a percentage by weight), Zn: 5.3-5.9%, Mg: 0.8-1.8%, Cu: <0.2%, Zr: 0.05 to 0.12%, Ti<0.15%, Mn<0.1%, Cr<0.1%, Si<0.15%, Fe<0.20%, impurities having an individual content of <0.05% each and <0.15% in total, the rest aluminum, The alloy may be used in a process comprising the steps of: (a) casting a thick block of an alloy according to the invention (b) solution heat treating said cast block at a temperature of 500 to 560° C. for 10 minutes to 20 hours, (c) cooling said solution heat treated block to a temperature below 100° C., (d) tempering said solution heat treated and cooled block by heating to 120 to 170° C. for 4 to 48 hours, In this process, said block is not subjected to any significant deformation by working between the casting and the tempering. The alloy and the method according to the invention are particularly useful for the manufacture of molds for injection-molding plastics. |