Impact of interannealing on recrystallization during final annealing in twin-belt cast Al–Fe–Si sheet

Abstract

Abstract The impact of interannealing on the recrystallization process in a twin-belt cast AlFeSi alloy was investigated by means of calorimetry, microstructural analysis, electrical conductivity, hardness measurements and cupping tests. The AlFeSi hot band cold-rolled to 1 mm without interannealing offers a higher precipitation capacity than that interannealed at 4 mm. The response to annealing of the former is therefore dominated by precipitation activities. Recrystallization is sluggish, lasts until 623 K and produces relatively coarse grains. The interannealed sheet, on the other hand, softens fully at 573 K via a typical two-stage, recovery and recrystallization reaction. The limited precipitation capacity in the latter allows recrystallization to occur primarily in a discontinuous fashion. This helps to balance the rolling texture inherited from the prior cold-rolling passes. In sheet samples processed without interannealing, the nucleation rate and the volume fraction of the discontinuously recrystallized grains are greatly reduced, owing to extensive concurrent precipitation. This reduces the strength of the annealing texture components which thus fail to balance the rolling texture after annealing.