铝合金半固态成形技术进展

利用半固态成形技术制备高性能铝合金是铝合金成形技术的重要研究方向之一。本文将从半固态成形用铝合金材料、制浆工艺及应用方面开展了大量的研究。研究结果得出：铝合金晶粒明显细化、尺寸更加均匀、制备了细小的等轴的半固态浆料组织、获得的力学性能更佳。指出目前研究中存在的问题,并展望了铝合金半固态成形未来的发展方向。     

铝合金半固态加工技术的应用研究

重点介绍了近年来在铝合金半固态坯料制备方面的研究进展以及在半固态触变成形技术工业应用方面的研究开发工作,如复合电磁搅拌制备半固态浆料、多流电磁搅拌半固态连铸技术、铝合金半固态触变压铸成形、铝合金半固态触变模锻成形等,并就其可能的应用领域及发展状况如难铸造合金的铸造成形、变形合金的直接铸造成形、活塞合金的加工成形、变形铝合金的塑性加工进行了讨论。     

铝合金半固态成形技术与设备进展

对铝合金半固态成形技术现状、半固态金属的制备方法、铝合金半固态成形设备及其技术的应用等方面进行了综述.     

变形铝合金半固态近净成形研究进展

变形铝合金强度高、塑性好,在工业轻量化发展中极具潜力。其凝固成形缺陷较多,塑性成形难以近净成形出外形较复杂的零件,且生产成本较高。半固态工艺结合了铸锻工艺的优点,利用半固态工艺优势提升变形合金材料的性价比,研究复杂外形的高性能变形铝合金零件的半固态成形成为半固态领域的一个研究热点。结合研究现状,分别从变形铝合金半固态成形的适应性,坯料和浆料的制备,触变成形与流变成形组织与性能方面进行了分析。并对需要进一步解决的问题及发展前景作了探讨。     

铝合金的半固态成形

半固态加工是金属材料成形领域中的一种新工艺。分析了铝合金半固态成形技术的现状及发展趋向。     

A356铝合金轮毂半固态挤压铸造成形数值模拟

通过建立A356铝合金的半固态表观粘度模型,采用计算机模拟方法对A356铝合金轮毂半固态挤压铸造成形工艺进行了研究.通过分析挤压速度、半固态浆料充填温度及模具预热温度对铝合金轮毂半固态成形性能的影响,探讨了不同条件下的金属流动特点和温度分布规律.结果表明,对该尺寸铝合金轮毂的最佳成形工艺:半固态浆料充填温度为600℃,模具预热温度为300℃,挤压速度为5 mm/s,保压时间为25 s.     

低压半固态铸造A356铝合金轮毂成形工艺的模拟与缺陷分析

利用ADSTEFAN 2012软件模拟了低压半固态铸造A356铝合金轮毂的充型和凝固情况,并结合模拟结果成形轮毂。对成形轮毂进行缺陷分析以验证模拟结果,得出合适的低压半固态铸造铝合金轮毂成形工艺。结果表明:低压半固态铸造A356铝合金轮毂成形的最佳铝液温度为610℃,模具温度为400℃,有利于保证充型的完整和顺序凝固。     

6061铝合金半固态成形过程数值分析

在热模拟压缩试验的基础上,对半固态触变成形本构关系及半固态流变黏度模型进行了研究并给出了相应的本构方程.采用DEFORM-3D模拟了6061铝合金轮毂半固态触变成形过程,进行了模具优化和成形力的分析.采用ANYCASTING模拟了两种铝合金零部件的流变成形,分析了模具尺寸、充型温度及充型速度对铝合金半固态浆料充型过程的影响,获得了最佳半固态成形工艺,并对铸件缺陷进行了预测分析.     

LSPSF流变铸造工艺及其应用

以铝合金流变成形应用基础研究为着眼点,主要介绍了南昌大学近几年在半固态浆料快速制备、半固态组织形成机理、半固态浆料直接成形技术及成形件的热处理强化等3个方面的工作,以推动流变成形技术在我国工业中的应用。     

变形铝合金半固态模锻成形件热处理新工艺探索

根据变形铝合金的热处理原理及其半固态模锻成形特点,探索出一种适合于变形铝合金半固态模锻成形件"高温固溶处理+分级时效"的新工艺:固溶处理(500±5)℃×25 min,分级时效140℃×6 h+150℃×1 h。结果表明:变形铝合金半固态模锻成形件经新工艺处理后,力学性能明显提高,缩短了处理时间,节约了能源,提高了生产效率。     

镁及镁合金的晶粒细化

叙述了镁及镁合金晶粒细化的几种方法，如熔剂处理法、熔体过热法、熔体搅拌法、合金化细化晶粒、固态变形处理、半固态成形及快速凝固工艺等。细化镁合金晶粒尺寸能显著提高其力学性能，这对推广镁合金的应用具有重要意义。     

细晶镁合金的制备方法

镁合金具有密度小，比强度高等特点，广泛应用于电子、交通、宇航等行业中。常规镁合金的加工性能差，易腐蚀，因而限制了它的应用。但如果其晶粒细小到一定程度，则会出现质的变化。综述了制备细晶镁合金的方法，包括等径角挤压、添加适当的合金元素、大挤压比热挤压、形变热处理、快速凝固等工艺的特点。     

Aluminiumanwendung im Schiffbau – Korrosion,Korrosionsschutz, Festigkeit und Fertigung

Application of aluminium in shipbuilding – Corrosion, corrosion protection, strength and fabrication The general application of aluminium alloys in shipbuilding are presented with respect to the subjects strength, fabrication, corrosion and corrosion protection. Specifically the problem of aluminium pipes for seawater cooling applications is elucitated. Corrosion test results, achieved by closed loop tested of longitudinal and circumferential welded aluminium pipes made of alloy AlMg 4,5 Mn are presented.     

The effect of twin spot beam arrangement on energy coupling during welding. Study of twin spot Nd:YAG laser welding of aluminium alloys

Laser welding, regarded as one of the welding techniques for use with steel materials and employed in the fabrication of automobiles, has increasing applications in the manufacture of transmission systems and car bodies; however, there are not many examples of application to aluminium alloy components.¹ The reasons for this are thought to be as follows: aluminium alloys have a higher laser reflectivity compared with that of steel materials; consequently an even higher power laser is required to input energy to the material for welding and also, due to the low viscosity of molten aluminium alloy, stable welding is difficult.^2,3     

Aluminum alloys anodisation for nanotemplates application

The aim of this investigation was to reveal the processing differences in achieving nanoporous anodized aluminium from aluminium alloys and their application for cobalt nanowires electrodeposition. The following types of aluminium were tested: pure Al (99.99%), and commercial alloys: AA1050, 6082 and 6060. Because of the differences in the surface temperature and high voltages during the anodizing steps, some stresses can be built up in the material. Therefore a strict temperature control should be done to limit thermal stresses in materials. Alloying elements (Si, Mg) cause precipitates that are observed on the surface, especially for 6060 alloy. Nevertheless, a nanoporous structure can be obtained at the end of second anodization step on all aluminium alloys investigated. It was shown that the number density of pores on the surface is practically independent on the aluminium alloys used. However, the degree of hexagonal distribution of the pores depends on the type of anodized aluminium alloy. Also, a successful fabrication of Co nanowire arrays using nanoporous anodic alumina template produced on Al alloy has been demonstrated, and the uniform filling of the template by cobalt nanowires arrays is discussed.     

The technology of extrusion‐fusion welding of polythene and polypropylene butt and T joints

Abstract

Laser welding, regarded as one of the welding techniques for use with steel materials and employed in the fabrication of automobiles, has increasing applications in the manufacture of transmission systems and car bodies; however, there are not many examples of application to aluminium alloy components.¹ The reasons for this are thought to be as follows: aluminium alloys have a higher laser reflectivity compared with that of steel materials; consequently an even higher power laser is required to input energy to the material for welding and also, due to the low viscosity of molten aluminium alloy, stable welding is difficult.^2,3     

铝合金铸造工艺CAD/CAE技术的研究与应用

介绍了铝合金铸造工艺CAD/CAE技术研究的主要内容及其应用,并给出了实例。实践应用表明,铝合金铸造工艺CAD/CAE技术能有效地应用于铝合金铸件的工艺设计和模拟分析,很好地为实际铝合金铸件生产服务。     

High-temperature mechanical properties of aluminium alloys reinforced with titanium diboride （TiB2） particles

The physical and mechanical properties of metal matrix composites were improved by the addition of reinforcements.The mechanical properties of particulate-reinforced metal-matrix composites based on aluminium alloys (6061 and 7015) at high temperatures were studied.Titanium diboride (TiB2) particles were used as the reinforcement.All the composites were produced by hot extrusion.The tensile properties and fracture characteristics of these materials were investigated at room temperature and at high temperatures to determine their ultimate strength and strain to failure.The fracture surface was analysed by scanning electron microscopy.TiB2 particles provide high stability of the aluminium alloys (6061 and 7015) in the fabrication process.An improvement in the mechanical behaviour was achieved by adding TiB2 particles as reinforcement in both the aluminium alloys.Adding TiB2 particles reduces the ductility of the aluminium alloys but does not change the microscopic mode of failure,and the fracture surface exhibits a ductile appearance with dimples formed by coalescence.     

Entwicklung und Aufbau einer Meßmethode zur realitätsnahen Beurteilung des Spaltkorrosionsverhaltens am Beispiel von Aluminiumwerkstoffen

Development and construction of a measuring technique for a realistic evaluation of the crevice corrosion behaviour by way of aluminium alloys Aluminium alloys represent a high percentage of materials used in aircraft. Complex designs such as those found in the aircraft industry illustrate a number of constructively determined geometrical crevices. As always the crevice corrosion behaviour of materials is difficult to reconstruct and evaluate in a laboratory. The authors present an experimental set up which reflects the situation in constructively determined crevices. It will be shown, with the use of selected aluminium alloys, that a quite good evaluation of crevice corrosion behaviour of materials is possible. The acidification and enrichment of selected species can be observed very well and their reaction on crevice corrosion can be semi‐quantitatively estimated. The interpretation of the corrosion results is overall improved.     

Morphology and corrosion characteristics of laser surface remelted Al‐Si alloy at cryogenic conditions

The properties and consequently functionality of equipment made of aluminium alloys are influenced by microstructural characteristics such as phase composition and grain size distribution in their surface layer. Nowadays, many surface engineering techniques have been applied to improve the surface properties of aluminium alloys, one of them being laser surface treatment. The effect of laser surface remelting at cryogenic conditions on the local chemical compositions, microstructure and corrosion characteristics of AlSi13Mg1CuNi aluminium alloy have been presented. The beneficial effect of laser treatment on the corrosion behaviour of the cast aluminium alloy in 0.01 M sulphuric acid solution was observed.