Effects of homogenisation treatment on microstructure and grain refinement of Al–1.2Mn alloy

ABSTRACTThe effects of a homogenisation treatment on precipitation, recrystallisation, grain refinement and texture in an Al–1.2Mn alloy were investigated. Based on hardness and electrical conductivity measurements, a precipitation–recrystallisation diagram was generated, which described the sequence of recrystallisation and precipitation. The results showed that recrystallisation was significantly retarded during the annealing treatment for the cold-rolled alloys with a supersaturated solid solution or with dense pre-existing dispersoids. If precipitation occurred prior to recrystallisation, the precipitates caused a strong resistance to recrystallisation, resulting in a coarse and elongated grain structure with a dominant normal direction-rotated cube texture. In contrast, when recrystallisation was completed before precipitation, recrystallisation was little affected by the precipitates, leading to a fine-grained structure with a weak cube texture.