METHOD OF MANUFACTURING A 7XXX-SERIES ALUMINIUM ALLOY PLATE PRODUCT HAVING IMPROVED FATIGUE FAILURE RESISTANCE

摘要

The invention relates to a method of manufacturing an 7xxx-seriesaluminium alloy plate product having improved fatigue failure resistance, the method comprising the steps of (a) casting an ingot made of an aluminium alloy of the 7xxx-series comprising (in wt.%): Zn 5 to 9, Mg 1 to 3, Cu 0 to 3,balance aluminium and incidental elements and impurities;(b) homogenizing and/or preheating the cast ingot; (c) hot rolling the ingot into a plate product by rolling the ingot with multiple rolling passes, characterized in that when the intermediate thickness of the plate is between 80 and 220 mm,at least a high reduction hot rolling pass is carried out with a thickness reduction of at least 25%,wherein the plate product has a final thickness of less than 75 mm. The invention is also related to an aluminium alloy plate product and an aerospace structural member produced by this method.