道次压下率对Al-Zn-Mg-Cu-Zr合金组织、力学性能及均匀性的影响

Evolution of Microstructure, Mechanical Properties and Homogeneity of Al-Zn-Mg-Cu-Zr Alloy Plates Prepared by Different Percentage Reductions per Pass

摘要:

通过实验和数值模拟的方法研究了道次压下率（PRPP）对7055铝合金板材的应变分布、微观组织、力学性能及其沿厚度方向的均匀性的影响。结果表明，总变形量相同的情况下，增大道次压下率，可以减小7055铝合金板材表层与中间层之间的等效应变差。道次压下率较小的工艺轧制板材的表层比中间层的再结晶比例高，并且中间层有尺寸较大的再结晶晶粒。然而，经道次压下率较大的工艺轧制的板材沿厚度方向有均匀的再结晶比例和再结晶晶粒尺寸。因此，道次压下率较大的轧制工艺可以提高板材组织和力学性能的均匀性。

Abstract:

The effects of percentage reduction per pass (PRPP) on the effective strain, microstructure, mechanical properties and through-thickness homogeneity of AA7055 alloy plates were investigated through experiments and numerical simulations. Results show that with consistent total strain, the difference between the effective strain values in the surface and middle layer of AA7055 alloy plates decreases with the increase of PRPP. In the plate rolled with small PRPP, the surface layer of plate contains higher recrystallization fraction, while the middle layer comprises of large recrystallized grains. In contrast, the plate rolled with large PRPP has consistent recrystallized grain size with consistent recrystallization fraction along the thickness direction. Thus, an improved homogeneity of the microstructure and mechanical properties along the plate thickness direction can be obtained through the rolling process with large PRPP.