微量Mn对Al-Mg-Si合金微观组织与拉伸性能的影响

Effects of minor manganese addition on microstructures and tensile properties of Al-Mg-Si alloys

研究了微量Mn对Al Mg Si合金的微观组织与拉伸性能的影响。结果表明 :微量Mn在Al Mg Si合金中主要以粒状α Al15(FeMn) 3 Si2 弥散相的形式存在 ,尺寸为 12～ 2 10nm ,均匀、弥散分布在基体中 ,有效地钉扎位错和亚晶界 ,抑制合金热挤压变形过程中的再结晶 ;均匀化处理过程中微量Mn可促进长针状 β Al9FeSi相向粒状α Al15(FeMn) 3 Si2 相转变 ,这种含Mn的α相弥散颗粒可作为合金时效强化相 β′(Mg2 Si)的非均匀成核位置 ,促进 β′相的析出 ,从而强化合金 。

The effects of minor addition of manganese on microstructure and tensile properties of Al-Mg-Si alloys are studied. The results show that minor Mn mainly exists in the form of spherical α-Al 15(FeMn) 3Si 2 dispersoids which can effectively pin dislocations and subgrain boundaries, inhibit the recrystallization of Mn-containing Al-Mg-Si alloys during hot extrusion as well as improve β′strengthening phase to precipitate in the process of ageing . The transformation of platelike β-Al 9FeSi to spherical α-Al 15(FeMn) 3Si 2 phase during homogenization is markedly accelerated by the addition of minor Mn in the Al-Mg-Si alloys. The addition of manganese significantly increases the strength of Al-Mg-Si alloys and make the alloy get a superior combination of strength and ductility.