6061/AZ31B/6061对称复合板的组织与力学性能研究

Research into Microstructure and Mechanical Properties of 6061 Al / AZ31B Mg / 6061 Al Symmetrical Laminated Plate

摘要:

本文在理论分析与模拟计算的基础上，通过热轧制备了6061 Al/AZ31B Mg/6061Al对称复合板，并对其组织结构和力学性能进行了研究。首先通过经典复合板理论计算得到了复合板中6061Al的最佳包覆率，再通过有限元方法模拟得到了复合板的最佳压下率。依据理论分析和仿真计算得到的铝的最佳包覆率和复合板的最佳压下率，对6061 Al/AZ31B Mg/6061Al复合板进行组坯，并在不同轧制温度、不同压下率和不同退火时间下进行了轧制实验，最后对实验得到的复合板进行了微观组织、拉伸性能和能谱分析。结果表明，在复合板的复合界面处的镁层中发现了再结晶晶粒，且界面上形成了由Mg17Al12和Mg2Al3组成的金属间化合物；随着轧制压下率的增大，6061 Al/AZ31B Mg/6061Al复合板的拉伸强度、延伸率和界面扩散厚度显著增大；随着轧制温度的升高，复合板的拉伸强度、延伸率和界面扩散厚度也增大；而随着退火时间的增加，复合板的拉伸强度降低，但界面扩散厚度增加。

Abstract:

In this paper, based on theoretical and simulation analysis, the 6061 Al / AZ31B Mg / 6061 Al laminated plates were fabricated by hot rolling, and the microstructure and mechanical properties were investigated in detail. The best coverage rate of 6061Al of the laminated plate was obtained by classical laminated plate theory and the optimal reduction rate of the laminated plate was obtained by Finite Element Method (FEM). According to the theoretical and simulation results, the rolling experiments of 6061 Al / AZ31B Mg / 6061 Al laminated plate were carried out with different rolling temperatures, reduction rates and annealing time. And the microstructure experiment, tensile property test and energy spectrum analysis of the laminated plates were carried out. The results showed that refined grains were discovered in the Mg layer at the interface, and the formation of an intermetallic compound layer consisting of Mg17Al12 and Mg2Al3 was identified at the interface. For the mechanical properties, with the increase of rolling reduction rate, the tensile strength, elongation and interface diffusion thickness of the 6061 Al / AZ31B Mg / 6061 Al laminated plate increased significantly; with the increase of rolling temperature, the tensile strength, elongation and interface diffusion thickness of the laminated plate decreased greatly; with the increase of annealing time, the tensile strength decreased and interface diffusion thickness of the laminated plate increased.