【摘要】 采用大变形锻造法,研究了7075铝合金在低温大变形下的显微组织的演化,为制取超细晶组织提供一个新的方法。利用透射电子显微镜分析了合金在不同条件下的组织形貌特征。结果表明,通过超低温大变形能够得到超细晶组织,晶粒尺寸约为0.5μm。对本实验中没有发现形变孪晶的原因进行了讨论。合金的变形机制主要是位错滑移,晶粒碎化和几何动态再结晶机制。更多还原

【Abstract】 The microstructure of Al-Zn-Mg alloy (7075 aluminum alloy) subjected to large plastic deformation by forging at a low temperature was studied by transmission electron microcopy (TEM) in order to provide a new way to get ultrafine-grained (UFG) microstructure. The microstructure characteristics of the alloy after different deformations were analyzed. It was found that the UFG microstructure with a size about 0.5μm could be fabricated by large plastic deformation at an extra low temperature. The major deformation mechanisms were found to be dislocation glide, grain breaking, and geometric dynamic recrystallization (GDRX).更多还原