拉伸性能的影響
(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院， 長(zhǎng)沙 410083;
2. 湖南大學(xué) 材料科學(xué)與工程學(xué)院， 長(zhǎng)沙 410082)
摘 要: 研究了微量Mn對(duì)Al-Mg-Si合金的微觀組織與拉伸性能的影響。結(jié)果表明：微量Mn在Al-Mg-Si合金中主要以粒狀α-Al15(FeMn)3Si2彌散相的形式存在，尺寸為12～210nm，均勻、彌散分布在基體中， 有效地釘扎位錯(cuò)和亞晶界，抑制合金熱擠壓變形過(guò)程中的再結(jié)晶； 均勻化處理過(guò)程中微量Mn可促進(jìn)長(zhǎng)針狀β-Al9FeSi相向粒狀α-Al15(FeMn)3Si2相轉(zhuǎn)變，這種含Mn的α相彌散顆粒可作為合金時(shí)效強(qiáng)化相β′（Mg2Si）的非均勻成核位置，促進(jìn)β′相的析出，從而強(qiáng)化合金，使合金獲得較好的強(qiáng)塑性配合。
關(guān)鍵字: Al-Mg-Si合金；微觀組織；拉伸性能；彌散相
（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
