拉伸性能的影响
(1. 中南大学 材料科学与工程学院， 长沙 410083;
2. 湖南大学 材料科学与工程学院， 长沙 410082)
摘 要: 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)3Si2弥散相的形式存在，尺寸为12～210nm，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)3Si2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′（Mg2Si）的非均匀成核位置，促进β′相的析出，从而强化合金，使合金获得较好的强塑性配合。
关键字: Al-Mg-Si合金；微观组织；拉伸性能；弥散相
（1. School of Materials Science and Engineering,
Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering,
Hunan University, Changsha 410082, China）
Abstract: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-Al15(FeMn)3Si2 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-Al9FeSi to spherical α-Al15(FeMn)3Si2 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.
Key words: Al-Mg-Si alloy; microstructures; tensile properties;dispersoids
