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Microalloying is thought to improve the performance of Al–Mg alloys commonly used in transport applications. The effect of Y addition (0–0.4%) on the microstructure, mechanical properties, and corrosion resistance of Al–9.2Mg–0.7Mn alloy is investigated for potential use in engineering applications. The generation of the β-Al3Mg2 phase along the grain boundaries is suppressed in the as-cast alloy due to the formation of the AlMgY ternary phase. The average intergranular corrosion mass loss of the alloy with 0.1% Y addition decreases about 53.1% almost at no expense of mechanical performance in the as-rolled alloy after annealing. Moreover, the alloy with 0.1% Y addition shows the corrosion mass loss about 30.2% lower than the Y-free alloy in the sensitized state. The enhanced corrosion resistance of the alloy can be ascribed to the reduced β-Al3Mg2 precipitation along the grain boundaries associated with Y addition. 相似文献
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Cu及热处理制度对Al—Mg—Si系合金晶间腐蚀敏感性的影响 总被引：6，自引：1，他引：6
采用浸泡腐蚀实验和电化学实验研究了强化元素Cu含量的改变及不同时效制度对Al-Mg-Si合金晶间腐蚀敏感性的影响,并利用XRD和SEM对腐蚀产物的构成及形貌进行了分析与观察,浸泡腐蚀实验结果表明：在峰时效的状态下,在0.5%Cu以上的合金中可观察到明显的晶间腐蚀而且随着Cu含量的增加,合金最大腐蚀深度增加;在欠时效状态下,1%Cu以上的合金中观察到了微弱的晶间腐蚀;在过时效状态下,所有实验合金均只出现点蚀,电化学实验结果表明：随着Cu含量的增加,合金的Ψcorr向正的方向变化,Jcorr增加,欠时效状态下的Ψcorr比峰时效状态下的负,腐蚀电流密度较小。 相似文献
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铝镁合金是未来应用汽车领域发展具有很大潜力的一类重要材料.通常,在商品中的铝镁合金,镁的质量分数在0.5%～13%.汽车制造商通常选用镁的质量分数在4.5%以上,然而研究发现,当镁的质量分数超过3%的时候,会引起晶界间腐蚀,从而造成应力腐蚀开裂.此现象未见文献对其进行系统的分析和研究.本文主要介绍铝镁合金在不同的热处理... 相似文献
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1 ＩｎｔｒｏｄｕｃｔｉｏｎＣｏｐｐｅｒａｌｌｏｙｓｈａｖｅｂｅｅｎｗｉｄｅｌｙｕｓｅｄｉｎｍａｒｉｎｅｅｎｇｉｎｅｅｒｉｎｇａｎｄｐｏｗｅｒｉｎｄｕｓｔｒｙａｎｄｏｔｈｅｒｉｎｄｕｓｔｒｙａｒｅａｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｈｉｇｈｅｒｓｔｒｅｎｇｔｈａｎｄｇｏｏｄｃｏｒｒｏｓｉｏｎｒｅｓｉｓ ｔａｎｃｅ[1～ 3].Ｔｈｅｔｙｐｉｃａｌｌｙａｎｄｗｉｄｅｌｙｕｓｅｄｃｏｐｐｅｒａｌｌｏｙｓａｒｅｂｒａｓｓａｎｄｃｕｐｒｏｎｉｃｋｅｌ ,ｉｎｗｈｉｃｈＣｕ∶Ｚｎｉｓｅｑｕａｌｔｏ 70∶3 0ａｎｄＣｕ∶Ｎ… 相似文献
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Noise measurements on crevice corrosion The importance of Al‐Mg‐Si‐alloys as an alternative to Al‐Cu‐Mg‐alloys has continuously increased in aircraft industry over the recent years. Al‐Mg‐Si‐alloys are corrosion resistant under normal atmospheric conditions. However localised corrosion, especially crevice corrosion, can be very dangerous. Pitting or crevice corrosion can be divided into an initial state and a propagation state of corrosion. The transition of a corrosion system from the passive state into the initial state of localized corrosion is characterised by the small fluctuation of the current and the potential. The measurement of this fluctuation is the subject of the electrochemical noise analysis (ENA). Therefore ENA leads to extensive knowledge about the activity of the corrosion system already in the pre‐damaged state. With the help of ENA the influence of crevice condition, potential and time on the initial state of the crevice corrosion on AA 6013 can be demonstrated. 相似文献
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The mechanical property of age‐hardenable Al‐alloys is governed by the state of ageing, which determines the microstructure and consequently, their corrosion behavior which is a vital aspect for a number of applications. This article presents a comparative assessment of corrosion behavior of under‐, peak‐ and over‐aged Al‐Mg‐Si alloy. Corrosion characteristics have been determined via immersion tests in 0.1 M ortho‐phosphoric acid solution and intergranular corrosion (IGC) tests. Corroded surfaces are examined by field emission scanning electron micrographs‐energy dispersive spectroscopy and 3D optical profilometer. The obtained results reveal that the corrosion rate at a specific immersion time as well as the depth of IGC increases in the order for under‐, peak‐, and over‐aged states. Irrespective of the state of ageing, corrosion loss increases linearly but the rate of corrosion decreases rapidly with increasing immersion time. The dominant mode of corrosion in under‐aged alloy is identified as localized pitting, while peak‐aged is highly susceptible to IGC in contrast extensive pitting corrosion is observed for over‐aged alloy. The observed differences in corrosion behavior are explained considering characteristics of precipitates. Formation of β (Mg2Si) in case of over‐aged alloy and presence of inclusions like AlFeMnSi particles are found to accelerate pitting corrosion. 相似文献
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Al-Mg-Si合金中Mg_2Si和Si粒子在晶间腐蚀过程中的作用机理 总被引：1，自引：0，他引：1
研究Al-Mg-Si合金晶界组成相（Al-Mg2Si及Al-Mg2Si-Si）间的电化学行为和动态电化学耦合行为,提出Al-Mg-Si合金的晶间腐蚀机理。研究表明,晶界Si的电位比其边缘Al基体的正,在整个腐蚀过程中作为阴极导致其边缘Al基体的阳极溶解;晶界Mg2Si的电位比其边缘Al基体的负,在腐蚀初期作为阳极发生阳极溶解,然而由于Mg2Si中活性较高的元素Mg的优先溶解,不活泼元素Si的富集,致使Mg2Si电位正移,甚至与其边缘Al基体发生极性转换,导致其边缘Al基体的阳极溶解。当n（Mg）/n（Si）〈1.73时,随着腐蚀的进行,合金晶界同时会有Mg2Si析出相和Si粒子,腐蚀首先萌生于Mg2Si相和Si边缘的无沉淀带,而后,Si粒子一方面导致其边缘无沉淀带严重的阳极溶解,另一方面加速Mg2Si和晶界无沉淀带的极性转换,从而促使腐蚀沿晶界Si粒子及Mg2Si粒子边缘向无沉淀带发展。 相似文献
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Localized corrosion morphologies of 2195 Al‐Li alloy with various heat treatment in 4.0% NaCl solution (pH 6.5) were investigated, and its corrosion mechanism was studied using a three‐electrode coupling system of α (Al) substituting for the precipitate‐free zone (PFZ), simulated bulk θ′ (Al2Cu) and T1 (Al2CuLi). θ′ acts as cathodic zone in the alloy. At the initial stage, T1 phase is active with respect to θ′ and α (Al), and endures the main anodic current, indicating that anodic dissolution occurs on T1. However, its potential moves to positive direction with immersion time, due to dealloying of Li from T1. As a result, the main anodic dissolution occurs on α (Al) at a later stage. At this stage, as only T1 and α (Al) are coupled, T1 is cathodic to α (Al). In real 2195 alloy, T1 phase is very tiny, and anodic dissolution of T1 and PFZ occurs alternately. These results show that its intergranular corrosion or intersubgranular corrosion is caused by alternate anodic dissolution of T1 phase and PFZ along grain and subgrain boundaries. 相似文献
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Microanalytical, mechanical, and corrosion studies were undertaken to investigate the effect of nano‐precipitates of Al(Scx−1Zrx) on the mechanical and corrosion characteristics of Al 2.5 alloy containing 0, 0.15, 0.3, 0.6, and 0.9 wt% of Sc with 0.15 wt% Zr. Addition of 0.3% Sc significantly increased the yield strength due to small precipitates sizes (5–19 nm) and the high coherency of the nano‐particles. Largest contributor to the strength was grain boundary strengthening caused by pinning of grain boundary precipitates. The alloys showed a good resistance to corrosion in 3.5 wt% neutral chloride solution. The alloy offered a high passivation tendency because of homogeneous coherent nano Al(Scx−1Zrx) precipitates. The nano precipitates interfaces and homogeneously distributed Al3Sc precipitates offer a high degree of corrosion resistance to Al 2.5 Mg Sc alloys compared to conventional aluminum alloys, such as Al 6061 and Al6013. 相似文献
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采用光学显微镜和场发射扫描电镜,研究超声波对原位 Mg2Si/Al 复合材料中初生 Mg2Si 形态的影响。研究结果表明：超声波处理使初生Mg2Si的晶粒尺寸从150μm降低到20μm,初生Mg2Si形态发生改变。在二维形貌中,未实施超声波振动处理的初生Mg2Si晶粒生长为含有空腔的粗大颗粒,共晶组织生长于其中,相应的三维形态为含有漏斗状空腔的八面体和十四面体。超声波处理后的初生Mg2Si晶粒变成细小、实心三维形态的颗粒,颗粒棱角已发生钝化效应。 相似文献
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不同轧制变形量的镍基690合金试样在1120℃×5 min的固溶处理和720℃×10 h的脱敏处理后,进行了晶粒度、特殊晶界比例及晶间腐蚀性能研究。结果表明,晶粒度随着轧制变形量的增加而升高,晶粒尺寸减小;特殊晶界比例在5%变形量试样达到最高,为67.7%,并随着轧制变形量的增加而减小,67%冷轧时特殊晶界比例降低到25.4%;ASTM G28-A法晶间腐蚀减重5%变形量的试样达到最低。 相似文献
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Neeta Magaji Robert Mayrhofer Benjamin Krger Christian Schnatterer Daniela Zander 《工业材料与腐蚀》2019,70(7):1192-1204
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利用形变及热处理工艺提高了690合金的低Σ重位点阵（Coincidence Site Lattice, CSL）晶界比例,通过电子背散射衍射（EBSD）技术表征了由不同类型晶界构成的网络特征,结果表明通过晶界工程处理,能够形成以大尺寸“互有Σ3n取向关系晶粒的团簇”显微组织为特征的晶界网络分布,这种显微组织是再结晶过程中多重孪晶充分发展的结果。通过晶间腐蚀浸泡实验表明通过晶界工程处理的样品抗晶间腐蚀性能较未经过晶界工程处理的样品明显提高。腐蚀后样品的显微形貌表明大尺寸“互有Σ3 n 取向关系晶粒的团簇”能够阻止晶间腐蚀向样品内部扩展,并且能够保护下层的显微组织。 相似文献
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通过冷轧和退火获得具有不同晶粒尺寸(8.7～79.2μm)的5083铝合金板.研究其微观结构、晶间腐蚀(IGC)、应力腐蚀开裂(SCC)和裂纹扩展行为.结果表明,粗晶粒样品表现出更好的抗IGC性能,其腐蚀深度为15μm.慢应变速率测试结果表明,细晶粒样品表现出更好的抗SCC性能,敏感性指数ISSRT为11.2％.此外,... 相似文献
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对6005A铝合金搅拌摩擦焊接头的晶间腐蚀行为进行了研究.结果表明,母材的晶间腐蚀倾向最大,热影响区(HAZ)次之,焊核区(NZ)和热力影响区(TMAZ)的晶间腐蚀倾向最低.结合场发射扫描电镜、高分辨透射电镜分析解释了接头不同区域的腐蚀行为:母材的晶间腐蚀是两组微电池效应的结果,即晶界析出相/沉淀无析出带(PFZ)和铝基体/PFZ;HAZ内晶界析出相的数量的减少、间距的变大及晶内Q'相的析出显著改善了该区的晶间腐蚀性,但晶内Q'相的析出也引起了点蚀的发生;NZ和TMAZ内绝大部分的合金元素固溶于基体,抑制了晶间腐蚀的发生. 相似文献
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Sr对Al-Si-Mg铸造合金中Mg2Si相结晶行为影响的研究 总被引：2，自引：1，他引：2
采用光学显微镜和扫描电镜观察了不同Sr量Al 11 6 %Si 0 4%Mg合金的组织变化 ,并分析了Sr的存在对Mg2 Si相结晶行为的影响。在未完全变质合金中 ,Mg2 Si相以网络状或笋状等形式存在 ,与共晶Si片之间存在附着生长关系。而在完全变质合金中 ,Mg2 Si相以细小的颗粒相形式孤立地存在于共晶团边界上 ,数量极少。Sr的存在对Mg2 Si相凝固结晶行为产生了重要的影响 ,这与枝晶α的数量和共晶Si的变质程度等因素有关 相似文献
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