铸铁在铝液中浸蚀机理的探讨

研究了铸铁在铝液中的浸蚀机理，发现铸铁在铝液中是通过铝原子的扩散，形成铁铝合金层后剥落和溶解造成浸蚀的。铸铁中的片状石墨对铝原子的扩散有很好的阻碍作用，并在铸铁表面上形成由石墨碳、Al_4C_3和铁铝化合物组成的保护层，进一步提高铸铁在铝液中的耐浸蚀性能。获得均匀分布的细小A型石墨，消除碳化物有利于提高耐浸蚀性能。     

铝合金玻璃纤维过滤材料的应用

性能优异,作用特殊,应用广泛的玻璃纤维过滤材料,在现代科学技术发展中越来越引人注目,玻璃纤维在铝合金铸锭、铸件生产的过滤中起到良好的作用。 无碱玻璃溶液经拉丝,织布,化学酚醛浸渍、烘焙,最后成型为过滤网布。它的耐热性,化学稳定性优异,用于铝合金过滤热稳定性很高,可以在720-730℃温度范围内使用,在铝合金过滤时不会被浸蚀。 铝过滤网布在对减少铝液夹渣及氧化膜杂质有明显效果。     

液态铝硅合金的浸蚀研究

1 前言 铝硅合金作为高密度的固-液相变储能材料,在热能储存技术中已获得实际应用,其关键技术之一就是控制铝硅溶体对容器材料的浸蚀。如将温度控制在铝硅合金的熔点附近(约600℃,低于铁铝共晶温度655℃),这时只能生成贫铁的铁铝硅三元合金体系,浸蚀层的扩散生长速度减小,从而使容器材料的抗浸能力大为提高。本工作研究了熔点附近,铝硅溶体对几种金属材料的浸蚀程度以及浸蚀层的成份分布情况并探讨表面氧化膜的影响。     

钛酸铝陶瓷材料在铝熔体中的抗热震行为及热膨胀特性的研究

钛酸铝陶瓷材料具有低膨胀、抗热震和与有色金属熔体不润湿等特性，是制备铝合金低压铸造机用易损件升液管、中间管，以及铝熔体熔炉内腔的首选材料。作者模拟升液管的应用条件，将钛酸铝陶瓷试块浸润到铝熔体中(750℃)，周期性间隔lh取出，测试其室温抗弯强度和热膨胀性能的变化，研究了钛酸铝陶瓷材料的抗热震性能。发现钛酸铝陶瓷经历最初的热震时，强度变化较大，但抗弯强度仍保持在30MPa左右，经历10次浸润和热震后，强度基本恒定，约为初始抗弯强度(36MPa)的80％，抗热震性能优良，可以适应铝合金低压铸造的间歇应用。     

H13和H11钢在A356铝合金热液中的静态浸蚀

研究了H13钢和H11钢在680℃热铝合金液中浸蚀1、3和5 h的腐蚀过程。结果表明:随浸蚀时间延长,两种钢均从局部腐蚀扩展为全面腐蚀,且钢材质量损失逐渐增大,但H13钢受浸蚀影响更大,当浸蚀5 h时,H13钢损失17.58 g,而H11钢仅损失2.68 g。两种材料的腐蚀均开始于α铁素体的位置,5 h后与铝合金界面均出现复合层过渡区,H13钢表面形成3重复合层形貌,且过渡区平均厚度为100μm,H11钢表面形成两重复合层形貌,且过渡区平均厚度为210μm。     

陶瓷-金属-合金三层复合材料坩埚的液态成形法研究

采用黑刚玉为陶瓷，过共析钢为基体金属，硅铁为合金构成三层复合材料坩埚。目的分别是抵抗铝金属液体的浸蚀，使材料具有一定强度且能抵抗高温气体的氧化。金属粉涂料作用在于连接陶瓷和金属基体，复合材料坩埚经液态成形法一次制成。与目前普遍使用的中硅球铁相比，其抗铝液浸蚀的能力可以提高10倍以上。     

铝合金材料的新进展（2）

全面评述了国外近２０年来在铝－锂合金、粉末冶金铝合金、喷射沉积铝合金、超塑性铝合金和铝基复合材料方面的发展情况。简要介绍了我国上述材料的发展情况。     

不锈钢／铝（铝合金）不不锈钢多层复合板残余应应力研究

采用取条法和化学浸蚀法相结合对不锈钢／铝（铝合金）／不锈钢多层复合板的残余应力值进行了测量，结果表明外层不锈钢受到长度和宽度方面的残余应拉应力作用，随着轧制复合变形量的增加，多层复合板的残余应力值会逐渐增大，此外还通过热－力耦合的弹塑性有限元法对不锈钢／铝（铝合金）／不锈钢多层复合板的残余应力场进行了模拟仿真，并将模拟结果与试验测量进行了分析和对比。     

铝合金消失模铸造壳体针孔度控制

1 铝合金消失模铸造铝液充型特点及对铝液要求 铝合金消失模铸件是由铝液将白模"消失"掉,铝液取代白模空间,将白模空间变成铝液空间,冷凝形成铝合金铸件.在此过程中,铝液流动前沿存在着复杂的反应:①铝液前沿液态和少量气态白模热解产物与铝液、涂料及干砂间进行着物理化学反应和质量传输;②铝液与涂层和干砂及液(气)化及未液(气)化白模进行着热的传导、对流、辐射;③铝液热解白模、升温涂层、干砂等使得铝液温度下降.     

颗粒增强铝基复合材料6066Al／SiCp的时效析出特性

采用喷射共沉积工艺制备了6066Al基体铝合金以及含不同体积分数增强颗粒的6066Al/SiCp铝基复合材料，与常规则熔铸＋挤压的基体铝合金比较，喷射共沉积基体铝合金和复合材料的力学性能峰值时效时间明显缩短，即喷射共沉积6066Al和6066Al/SiCp颗粒增强铝基复合材料发生加速时效现象。对材料的微观组织进行常规金相和透射电镜观察，分析了SiCp增强陶瓷颗粒以及喷射共沉积工艺对材料时效析出行为的影响。研究表明：喷射共沉积工艺所形成的非平衡组织中溶质原子浓度高，时效析出驱动力大，有利于时效过程溶质原子扩散和第二相的形核。喷射共沉积材料细化的晶粒组织及复合材料中的高密度位错有利于非均匀形核，是加速材料时效析出动力学过程的主要原因。     

A 3D dynamic analysis of thermal behavior during single-pass multi-layer weld-based rapid prototyping

Weld-based rapid prototyping enables the capacity of forming 3D complex parts. In rapid prototyping there exists the particular thermal cycling, being repeatedly heated at the same place, which is the basic cause of complex thermal stress. In this paper experiments are carried out to investigate the thermal characters of single-pass ten-layer deposition. Meanwhile a 3D transient heat transfer numerical simulation with temperature-dependent material properties is conducted to investigate temperature field evolution, thermal cycling character, temperature gradient and the effects of depositing directions on the thermal process of single-pass ten-layer rapid prototyping. The calculated results match the experimental measurements well. The research results show that the heat diffusion condition of molten pool becomes worse as the depositing height increases. With other parameters being constant, the heat diffusion condition can be significantly improved by optimizing the depositing directions. The heat diffusion condition of component with the same depositing directions is better than reverse directions.     

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.     

驱动力对2219铝合金DLBSW焊接熔池行为的影响

为了探索激光焊接熔池驱动力与焊接过程中熔池流动之间的关系,构建2219铝合金T形结构双激光束双侧同步焊接(dual laser-beam bilateral synchronous welding,DLBSW)过程热-流耦合模型.分析表面张力、反冲压力、重力及热浮力对熔池流动的驱动作用,并阐述这些驱动力共同作用下的熔池...     

In-flight oxidation of aluminum in the twin-wire electric arc process

This paper examines the in-flight oxidation of aluminum sprayed in air using the twin-wire electric arc (TWEA) thermal spray process. Aerodynamic shear at the droplet surface increases the amount of in-flight oxidation by promoting entrainment of the surface oxides within the molten droplet and continually exposing fresh fluid available for oxidation. Mathematical predictions herein confirm experimental measurements that reveal an elevated, nearly constant surface temperature (∼2273 K) of the droplets during flight. The calculated oxide volume fraction of a “typical” droplet with internal circulation compares favorably to the experimentally determined oxide content (3.3–12.7%) for a typical TWEA-sprayed aluminum coating sprayed onto a room temperature substrate. It is concluded that internal circulation within the molten aluminum droplet is a significant source of oxidation. This effect produces an oxide content nearly two orders of magnitude larger than that of a droplet without continual oxidation.     

Mechanism of removing inclusions from molten aluminum by stirring active molten flux

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铝基离子镀氮化物膜的研究

探讨了在铝及铝合金基体上离子镀ＴｉＮ薄膜的可行性，研究了各工艺因素和掺入微量Ｃｒ，Ｆｅ对ＴｉＮ膜质量及性能的影响，同时还研究了铝基离子镀ＴｉＮ薄膜的最佳工艺条件。结果表明，在铝合金基体上离子镀ＴｉＮ薄膜是可行的。     

A Complex Method of Applying Aluminum to Carbon Fiber

Technological pattern of applying aluminum to carbon fiber is developed. Initially, aluminum was applied to activated surface of high-modulus fiber by using one of two methods: vacuum deposition or thermolysis of aluminum-organic compounds. Then, electrodeposition from an ether–hydride bath under the reversing current conditions was performed. Finally, high-temperature impregnation of the samples in molten aluminum was followed by their pressing up to preset dimensions. It is advisable to heat a sample, at the stage of introducing the catalyst or during the thermolysis of aluminum-organic compounds, by passing electric current through it. By analyzing physico-chemical characteristics of the composites manufactured by the suggested processing, it was found that the tensile strength increased by 30 to 40% and the thermal stability, in the heating–cooling cycles, increased 1.5 to 2.0 times compared with samples obtained by simple impregnating carbon fiber in molten aluminum.     

Research for the method of image acquisition of the molten pool in the TIG welding of aluminum alloy

Obtaining the image of molten pool aluminum alloy‘ s tungsten inert gas (TIG) welding becomes a challenging problem in the welding field. In this paper, a bran-new optical sensor based analyzing the light spectrum was designed, and the clear image of the molten pool during the aluminum alloy‘ s welding using the common industrial CCD camera was obtained. And with the new algorithm provided by myself, the desirable characteristic parameters of the molten pool of aluminum alloy‘ s welding were obtained, and it provides a good base for advanced monitor welding quality.     

基于计算机的铝液质量检测系统的开发和应用

在SGJ-Ⅰ型铝液质量检测仪的基础上,用VC 开发了减压凝固试样密度法检测铝合金液质量的软件系统,组成了基于计算机的铝液质量检测仪,用于炉前快速检测铝合金液质量及试样致密性,间接评价铝液的含氢量.给出了系统的软硬件设计及应用实例.     

铝液净化的关键限制因素

从Al2O3杂膜和液态金属结构分析入手，阐述了气体在铝-杂H2系统中形核长大的全过程，提出“寄生机制”，并被试验和实践所证实，杂的存在是气体难以除净的关键限制因素，杂吸附着气，气寄生于杂，杂多气多，除气必排杂，排杂是除气的基础。