METHOD FOR PRODUCING A HIGH DAMAGE TOLERANT ALUMINIUM ALLOY

摘要

The present invention relates to a method of producing a high damage tolerant aluminum alloy rolled product a high toughness and an improved fatigue crack growth resistance, comprising the steps of a) casting an ingot having a composition selected from the from the group comprising of AA2000, AA5000, AA6000, and AA7000-series alloys; b) homogenising and/or pre-heating the ingot after casting; d) hot rolling the ingot into a hot rolled product and optionally cold rolling the hot rolled product into a cold rolled product, characterized in that the hot rolled product leaves the hot rolling mill at an hot-mill exit temperature (TExit) and cooling the hot rolled product from said TExit to 150~C or lower with a controlled cooling cycle with a cooling rate falling within the range defined by: T(t)= 50-(50-TExit)e.alpha..t and wherein T(t) is the temperature (~C) as function in time (hrs), t is the time (hours) and .alpha. is in the range of -0.09.plusmnØ05 /hrs-1).