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利用喷射成形和热挤压的方法制备了含锰为2%(质量分数)的高强铝合金Al-8.8Zn-2.9Mg-1.6Cu合金,用X射线衍射(XRD)、光学显微镜(OM)和扫描电镜(SEM)和透射电镜(TEM)等方法研究了铝合金的微观组织,并进行了力学性能测试.研究结果表明:喷射成形制备的含锰铝合金经过热挤压和固溶处理后,基体组织为细小均匀的再结晶晶粒组织,平均尺寸约8μm.MnAl6颗粒在喷射沉积过程中沿晶界析出,经过热挤压后,尺寸大的颗粒破碎,大部分的颗粒则沿挤压方向产生一定的塑性变形.固溶处理对MnAl6颗粒尺寸的影响不明显,但棒状/片状颗粒的边角处发生球化,有利于降低诱发显微裂纹的应力或应变集中.时效后,铝合金达强度为775MPa,延伸率达4.3%,断口以细小的韧窝为主,尺寸小于500nm.
High-strength aluminum alloy Al-8.8Zn-2.9Mg-1.6Cu alloy containing 2% manganese (Mn) was prepared by spray forming and hot extrusion. XRD, OM and SEM and TEM were used to study the microstructure of the aluminum alloy and the mechanical properties of the aluminum alloy were tested.The results show that after hot extrusion and solution treatment, The microstructure of the microstructure is fine and uniform recrystallized grain structure with an average size of about 8μm.MnAl6 particles are precipitated along the grain boundaries during spray deposition. After hot extrusion, the large size particles are broken, and most of the particles are extruded in the extrusion direction A certain degree of plastic deformation was produced.The effect of solution treatment on the grain size of MnAl6 was not obvious, but the spheroidization occurred at the corners of the rod-like grains, which was beneficial to reduce the concentration of stress or strain induced microcracks.After aging, The strength of 775MPa, the elongation rate of 4.3%, the fracture mainly dimples, the size of less than 500nm.