微量Sc对2A14铝合金轮毂组织与性能的影响

采用铸锭冶金及等温复合锻造方法,制备了含Sc的2A14铝合金轮毂锻坯,研究了Sc对锻坯组织与性能的影响。结果表明,Sc含量提高至0.3%时,2A14铝合金的晶粒得到明显的细化,大部分晶粒呈等轴晶状态。添加Sc提高了2A14铝合金的伸长率,但其抗拉强度明显降低,使其低于400MPa,原因在于添加Sc后,大量消耗2A14铝合金中的Cu元素,导致强化相θ′-Al2Cu体积分数减少。但Sc能有效抑制合金中的再结晶,减小轮毂锻坯各部位的性能差异,并提高合金的耐热性能。     

原位合成TiB2和Al3Ti对ZL201的晶粒细化效果

以工业纯铝、氟钛酸钾和氟硼酸钾为原料 ,通过原位反应合成的 Al-5Ti-B中间合金中 ,Ti B2 和 Al3Ti颗粒细小且弥散分布 ,对铝及 Al-Cu系合金有显著的晶粒细化效果 ,并且能大幅度提高 ZL 2 0 1合金的力学性能     

Use of the Devanathan-Stachurski cell to measure hydrogen permeation in aluminum alloys

The Devanathan-Stachurski (DS) cell has been successfully used to determine hydrogen permeation behavior in a wide variety of metals, but the DS cell has been much less successful with aluminum alloys. The DS literature is critically reviewed for aluminum alloys. An improved DS method is described and demonstrated for use with aluminum alloys (and probably Mg-based alloys). Experimental results are reported for the hydrogen diffusion coefficient, solubility, and trapping in the AA5083 aluminum alloy. The diffusion coefficient is reported for AA6061.     

铝及铝合金的等离子体渗氮研究进展

根据国内外近年来发表的有关铝及其合金等离子体渗氮的文献,讨论了渗氮工艺中存在的一些难题,并介绍了这方面的研究现状和进展情况。     

稀土在铝合金表面处理中的应用及研究进展

评述了稀土在铝合金表面处理中的应用及研究进展,尤其是铝合金稀土表面转化膜技术和稀土对铝合金阳极氧化的影响两方面.稀土表面转化膜能够提高铝合金的耐蚀性能,工艺以化学浸泡为主;稀土对铝合金阳极氧化是有益的:它使铝合金接受极化的能力增强,同时提高氧化膜的抗蚀性.因此,稀土应用于铝合金表面处理具有良好的发展前景.     

直流磁场对7075铝合金组织结构的影响

研究了在直流磁场下凝固的7075铝合金晶内溶质含量及凝固组织的变化。试验结果表明：与未施加磁场的试样相比，经过直流磁场处理后，7075铝合金中Zn、Mg、Cu3种溶质元素在晶粒内部的含量均增加。此外，直流磁场作用下，试样宏观组织的变化不明显，而晶内析出相的形貌和尺寸发生了显著变化，由无磁场时的粗大针状组织变为细小均匀的结构。探讨了磁场的作用机制。认为电磁场作用使得各溶质粒子对基体铝产生了相对运动，这种运动增强了溶质粒子在铝中的扩散，从而导致了晶内溶质含量的增加。     

双流浇注连续铸造铝合金梯度材料的工艺参数

从宏观的角度总结了影响双流浇注连续铸造制备铝合金梯度材料的因素，分析了确定浇注温度、铸造速度、内浇包的导流管设计等关键工艺参数时需要注意的问题，以便控制上述参数在一定的范围内变化，确保铝合金获得所期望的梯度分布。并以2024／3003合金的制备为例，提供了一些操作可行的参数，这些工作将为双流浇注连续铸造制备铝合金梯度材料提供指导。     

含钪铝合金的研究进展

钪是优化铝合金性能最为有效的合金元素，含钪铝合金强度高，塑性好，焊接性能，耐腐蚀性能等优良，是舰船、航空航天、核能等国防军工尖端领域用新一代铝合金结构材料，通过对Al-Mg-Sc和Al-Zn-Mg-Sc合金的研究状况分析，综述了钪与铝及铝合金的作用关系和对性能的改善作用。并提出我国含钪铝合金的研究方向。     

基于人工神经网络与遗传算法的Al-Mg-Si系合金抗拉强度预测模型

为了研究Al-Mg-Si系合金热处理制度和合金成分对力学性能的影响规律,采用人工神经网络（artificial neural network, ANN）和遗传算法（genetic algorithm, GA）相结合的方法,构建了Al-Mg-Si系合金强度预测模型（ANN-GA模型）。通过单因素和双因素分析,研究了合金元素含量和热处理工艺参数对铝合金抗拉强度的影响规律。结果表明,随着Si含量的增加,铝合金的抗拉强度呈现先降低后升高的趋势;随着Mg含量的增加、Cu含量的增加或者Fe含量的减少,铝合金的抗拉强度整体上呈现升高的趋势。双因素分析更能反映输入参数对铝合金抗拉强度的影响。Mg/Si比、Mg+Si总量和时效时间对Al-Mg-Si系合金力学性能的影响显著。铝合金的硬度随时间的变化趋势与ANN-GA模型的计算结果一致,峰值时效时间为29 h,相对误差为11.86%。     

Surface engineering with light alloys—Hard coatings, thin films, and plasma nitriding

Light alloys have been attracting increasing attention over the past decade, since they can be used to reduce weight and save energy. For many years, light metals such as titanium and aluminum have also been used to synthesize hard compound coatings such as physically vapor deposited (PVD) TiN, (Ti,Al)N, and chemically vapor deposited (CVD) Al₂O₃. The coatings field is developing rapidly. Combining plasma-aided coating and diffusion processes has led to the development of so-called “duplex treatment,” consisting of plasma nitriding and subsequent hard coating. Another interesting development is TiN coating of aluminum vacuum parts, such as pumps, to reduce degassing and make the cleaning of the surfaces easier. Despite the many advantageous properties of light alloys, their surface properties sometimes cause problems. For example, galling may be a severe problem with titanium parts, and plasma nitriding has been applied successfully to combat it. However, due to adherent oxide scale, plasma nitriding of aluminum has proven to be more difficult. In this paper, we discuss some recent trends in the application of plasma-aided coating, thin film deposition, and diffusion processes, and give practical examples of industrial applications.     

镁合金表面铝涂层研究新进展

对镁合金表面沉积铝涂层这一镁合金表面处理的新技术进行了总结,分析了传统镁合金表面处理的优缺点以及在镁合金表面沉积铝涂层的优势.最新的在镁合金表面沉积铝涂层的工艺主要有铝粉埋覆扩散法、铝粉刷涂埋覆扩散法、火焰喷涂热扩散法、电弧喷涂热压法、动态金属喷镀法.在对以上沉积原理的分析和理解的基础上,详细阐述了镁合金表面铝涂层的耐蚀机理,并指出了该技术的应用前景和制约其发展的主要因素.     

镁合金表面铝涂层研究进展

镁合金在现代工业中有着广泛的应用前景,但较差的耐蚀性能限制了其发展,沉积铝涂层技术作为改善镁合金表面性能的新技术得到了关注。综述了镁合金表面沉积铝涂层的技术研究现状,分析了此种技术的优势,介绍了在镁合金表面沉积铝涂层的几种主要方法:扩散铝涂层、物理气相沉积、化学气相沉积、高能束熔覆等,分析了各自的优缺点,并展望了镁合金表面铝涂层技术的发展趋势。     

飞机结构铝合金直接化学镀Ni-P合金研究

高强度铝合金被广泛用于飞机结构中,然而,这一系列铝合金抗腐蚀和耐磨性差,限制了其应用。而Ni-P合金镀层具有高的硬度和抗腐蚀性能等优异特点,成为增强表面性能的常用手段。采用化学镀镍工艺在铝合金（6061）表面进行化学镀镍处理,研究了pH值、沉积温度和沉积时间对沉积速率的影响。分析了化学镀镍层的成分和组织形貌,同时对镀层的硬度、抗腐蚀性进行了表征。试验表明,在铝合金表面化学镀镍可以显著提高铝合金表面的硬度,并改善其在5％NaCl溶液中的耐蚀性。     

H13钢铝合金压铸模的离子氮化

采用加氩渗氮和无氩渗氮两种离子渗氮方法,对用作铝合金压铸模材料的H13钢的热疲劳性能进行了比较.结果发现,无氩渗氮的化合物层对H13钢的热疲劳性能具有双重影响,一方面能推迟热疲劳裂纹的萌生,阻止热裂纹向基体内部扩展,另一方面表面裂纹直、宽、多,易于剥落并扩展快,因此,采用含化合物层的离子氮化处理H13钢铝合金压铸模应该慎重.     

稀土元素对铝合金组织与性能影响的研究进展

稀土元素因为其有效、稳定的变质作用,被广泛应用于多种金属材料中。变质处理可以细化合金组织,从而提高合金的力学性能,不同的稀土元素对铝合金的变质效果不同。重点介绍了几种常用稀土元素对铝合金显微组织、力学性能的影响及其变质机理,综述了现阶段国内外稀土铝合金的研究现状,并阐述目前存在的问题,以及对未来研究进行了展望。     

Use of acoustic emission technique for the early detection of aluminum alloys exfoliation corrosion

Exfoliation corrosion of aluminum alloys is a form of localized corrosion which affects many industries, specially aeronautics. The study of this corrosion mode using only electrochemical techniques is not fully efficient for the detection and control on line of this phenomenon. Therefore, we developed a non-destructive testing technique based on the acoustic emission recordings in order to follow-up this form of corrosion on aluminum alloys. Indeed, recent works have shown the interest of the acoustic emission for the detection, the monitoring and the localization of pitting corrosion on aluminum alloys. This pitting corrosion phenomenon is currently well understood and the experimental methodology acquired during that study is transposed to the study of exfoliation corrosion of aluminum alloys.The present study is conducted on two aluminum alloys: (Al 2024 T3, and Al 7449 T6 and T7). Samples are immersed 4 days in the modified ASTM STP 1134 saline solution. Observations of the structures after tests show that the exfoliation corrosion sensitivity of alloy 7449 T6 is more important than for alloy 7449 T7 which exhibits only the presence of small and non-occluded pits. Very severe exfoliation corrosion was also observed on Al 2024 T3, but after a longer immersion time or in a more acid solution.The recording of the acoustic emission activity shows evident links between this activity and the exfoliation corrosion rate. The analysis of the signal's characteristics reveals a population corresponding to the release of hydrogen bubbles. A few more energetic signals have also been observed. Their source can be either, the cracking resulting from the separation of sheets of metal, or the development and evolution of hydrogen bubbles formed inside blisters during exfoliation corrosion.     

基于ANSYS Workbench铝合金双轴疲劳试验仿真研究

主要以国家重大工程专项子项目《铝合金双轴额定细节疲劳强度试验研究》为依托,以十字形铝合金薄板试件为研究对象,利用有限元软件ANSYS Workbench建模并进行数值模拟,侧重研究十字形铝合金在0°、90°及180°三种相位差交变循环载荷作用下的应力分布、变形情况及疲劳寿命,比较分析了铝合金在不同相位差下双轴受力情况的差异,并对可视化的图形图像和计算结果进行了分析。通过与试验的对比确定了实际变形和理论分析基本一致,表明在ANSYS Workbench中建立的十字形铝合金试件模型是准确且可信的。在双轴疲劳试验中,应重点监控该十字形铝合金的中间圆孔区域,为大飞机用铝合金结构设计与强度评估提供了基础的技术支持。     

Ti13Nb13Zr 合金离子氮化层的摩擦磨损性能研究

目的提高医用钛合金的耐磨损性能。方法应用等离子渗氮技术在Ti13Nb13Zr基材上制备改性层,并对改性层组织、成分及硬度进行测试。利用往复磨损试验机研究改性层在干摩擦条件下的摩擦磨损性能,并与未处理的基材进行对比。结果 Ti13Nb13Zr合金表面经渗氮后形成致密均匀的改性层,硬度高达1110HV0.025,改性层的磨损体积约为基材的1/23。结论等离子渗氮技术有效地改善了Ti13Nb13Zr合金的摩擦磨损性能。     

中间合金对铝合金细化处理的现状分析与初探

分析讨论了中间合金对铝合金晶粒细化处理的研究与应用现状及其细化机理;并对新型细化剂AITiBRE中国合金的细化效果进行初探,结果表明该中间合金是一种高效、长效的晶粒细化剂,对压力罐用铝材具有显著的细化作用,其效果优于进口的A15TilB细化剂。     

Plasma-Assisted Nitriding of Aluminum-Alloy Parts

Plasma-assisted nitriding of aluminum alloys promises to become a suitable alternative to variants of thermochemical treatment used for raising the wear resistance of these materials especially from the standpoint of the environmental effect. Process performed in vacuum with the use of nitrogen and an argon-hydrogen mixture as the process gas provides for the formation of a layer of compounds (aluminum nitrides) with enhanced hardness on various aluminum alloys. However, until the present the process has been used only at the laboratory scale. No data can be found in the literature, for example, on the effect of the batch size on the uniformity of the thickness of the nitrided layer or on the wear resistance of parts from aluminum alloys. The present work is a study of plasma-assisted nitriding of commercially produced parts (pistons) fabricated from an aluminum alloy. The parameters of the process are chosen after the determining optimum conditions for preliminary sputtering treatment. Special attention is devoted to provision of temperature uniformity within a batch and the possibility of improving the surface quality by increasing the thickness of the compound layer. The topography of the surface and the thickness, chemical composition, and hardness of the compound layer are studied by the methods of scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), metallography, and measurement of ultramicrohardness. The performance characteristics of untreated, nitrided, and anodized pistons are evaluated with the help of vibration wear tests with a rider fabricated from a standard material. The results of the tests show that the wear resistance of some nitrided pistons is comparable to that of anodized parts.