关键词: 7A85铝合金, 固溶处理, 动力学模型, 晶粒尺寸

Abstract: Grain growth behavior of 7A85 aluminum alloy during solution treatment heating and holding was tested by using DIL805 dilatometer. Effects of heating rate, holding temperature, and holding time on the α-Al grain size were statistically analyzed, and grain growth kinetic models for the heating and holding were established respectively. The results show that the grain growth behavior of the 7A85 aluminum alloy during solution treatment can be divided into two stages: first, the static recrystallization and growth behavior of cold-rolled deformed grains in the heating stage; second, the grain growth behavior in the holding stage. During the heating stage, the higher the heating temperature, the larger the α-Al grain size; the faster the heating rate, the smaller the α-Al grain size. During the holding stage, as the holding time extends, the α-Al grain size gradually increases, and the grain growth rate is faster in the early stage of holding. The relative errors of the calculation results of the growth kinetic models during the heating and holding stages are within 5% and 8%, indicating a high prediction accuracy.

Key words: 7A85 aluminum alloy, solution treatment, kinetic model, grain size