AE81镁合金轧制变形显微组织演变的研究

    Study on Microstructure Evolution of AE81 Magnesium Alloy during Rolling

    • 摘要: 通过重力铸造法制备了AE81稀土镁合金,并对固溶处理后的合金在300℃和350℃进行压下量分别为15%、20%、25%和30%的轧制变形。结果表明:稀土元素Ce的加入导致铸态组织中Mg17Al12相不连续分布,镁基体上分布的Al4Ce相以块状形貌、中空管状形貌和针状形貌存在。轧制变形后,AE81合金所产生的变形组织的体积分数随着压下量的增大而增大,当压下量增大到25%时出现了明显的动态再结晶现象,再结晶晶粒的平均尺寸主要分布在200~400nm之间,且动态再结晶区域主要分布在Al4Ce相周围。同时,Mg17Al12析出相的体积分数随着轧制温度和压下量的增大而增大,Mg17Al12相在基体上的分布得到改善。

       

      Abstract: AE81 rare earth magnesium alloy was prepared by gravity casting method, and the alloy after solution treatment was subjected to rolling deformation at 300℃ and 350℃ for 15%, 20%, 25% and 30%, respectively. The results show that the addition of rare earth element Ce causes the discontinuous distribution of Mg17Al12 phase in the as-cast microstructure, and the Al4Ce phase in the magnesium matrix exists in the shape of block, hollow tube and needle. After rolling deformation, the volume fraction of the deformed microstructure in AE81 alloy increases with the increase of the reduction amount. When the reduction amount increases to 25%, obvious dynamic recrystallization phenomenon occurs. The average size of the recrystallized grains is mainly distributed between 200 nm and 400 nm, and the dynamic recrystallization region is mainly distributed around the Al4Ce phase. Meanwhile, the volume fraction of Mg17Al12 precipitated phase increases with the increase of rolling temperature and reduction, and the distribution of Mg17Al12 phase on the matrix is improved.

       

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