微量 Mn 元素对超高强铝合金锻件平面力学性能各向异性的影响

摘要

The effects of the micro Mn element on the in-plane anisotropy of the extruded plate and its isother-mal forged piece,which was made of super ultra-high strength Al-Zn-Mg-Cu alloy,were investigated by optical mi-croscopy,scanning electron microscopy,X-ray diffraction and tensile tests.The results indicate that the addition of Mn leads to large amount of second phase containing Mn and promotes the recrystallization of the extruded plate.The intensity of the recrystallization texture increases with the decrease of the deformation texture.As a result,the in-plane anisotropy of the tensile mechanical properties is refined.In addition,the dispersed Mn-containing second phases make alloy transfer into transgranular ductile fracture,which improves the elongation of the alloy.%通过金相显微镜、扫描电镜、XRD 衍射仪以及拉伸力学性能测试研究了微量 Mn 元素对 Al-Zn-Mg-Cu超高强铝合金挤压带板及其制备的等温模锻件的平面力学性能各向异性的影响。结果表明，微量 Mn 元素的加入可以产生大量含 Mn 第二相，促进超高强铝合金锻件的再结晶，使变形织构强度减弱，再结晶织构强度增加，降低高强铝合金锻件的平面力学性能各向异性。此外，弥散细小的含锰相使合金断裂形式转变为穿晶延性断裂，提高了合金的延伸率。