铝锂合金无中间层扩散焊接工艺研究

概述了铝锂合金超塑成形 /扩散焊接技术的现状 ,研究了铝锂合金无中间层扩散焊接工艺 ,通过选取适当的工艺参数和焊接前化学处理 ,使焊件获得较高的剪切强度。     

铝锂合金搅拌摩擦焊研究进展

铝锂合金作为一种低密度、高性能的新型结构材料,被认为是航空航天领域中实现飞行器轻量化的理想结构材料之一。而搅拌摩擦焊作为一种固相焊接技术,能够克服铝锂合金熔化焊时易产生的裂纹、气孔等缺陷,在铝锂合金焊接领域具有重要的应用前景。从搅拌摩擦焊焊接工艺、接头组织与性能等方面综述了铝锂合金搅拌摩擦焊近几年的研究进展,总结了其存在的主要问题,并对铝锂合金搅拌摩擦焊技术未来的发展进行了展望。     

铝锂合金焊接技术的研究现状分析

铝锂合金作为轻质、高性能材料,得到广泛的应用,铝锂合金连接质量和应用受到焊接方法的影响,采取不同焊接方法对于连接区域性能产生不同影响,可能会造成焊接区域性能改变,因此焊接方法成为人们研究的热门问题。基于此,该文先对铝锂合金成分进行了深入分析,然后对铝锂合金焊接技术进行详细分析。以期通过采取合适的焊接技术,可以减少焊接方法对于铝锂合金质量的影响,保证焊接连接区域性能满足质量要求,推动铝锂合金的广泛应用。     

铝锂合金及其焊接技术及其研究进展

铝锂合金有着广泛的应用领域,它是重量比较轻、研究比较先进的一种合金材料,受到了全世界各个国家的关注。铝锂合金在焊接方面有着很大的难度,焊接技术存在着一些问题如焊接接头的强度不够,气孔敏感性高等。本文讨论了铝锂合金技术的开发应用,阐述了铝锂合金焊接技术以及焊接上存在的问题,希望对以后的应用有所帮助。     

热应变对2090铝锂合金焊接热影响区显微组织和力学性能的影响

采用焊接热模拟实验方法研究了在焊接热循环和应力－应变循环同时作用下，２０９０铝锂合金妆热影响显微组织和力学性能的变化特性，结果表明，在焊接热应变作用下，应变使合金中强化数量增多，晶车化，从而降低了２０９０铝锂合金焊接热影响我的软化倾向。     

焊后热处理对2091铝锂合金接头机械性能的影响

研究了２０９１铝锂合金焊后热处理对焊接接头机械性能的影响，结果表明，对２０９１铝锂合金进行焊后热处理，可以显著提高其接头强度，对塑性的影响不明显。     

5A90铝锂合金激光焊搭接接头的组织和性能

以厚度为3.0和4.0 mm的5A90铝锂合金板为研究对象,系统地开展了铝锂合金双光点激光焊接工艺研究,并对激光焊搭接接头的组织和性能进行了分析。结果表明:通过合理的选择激光功率和焊接速度可保证焊接过程的稳定性,改善焊缝的成形质量;在母材半熔化区与焊缝柱状晶之间存在一条等轴细晶带,焊缝中心组织为等轴树枝晶,晶粒尺寸一般随激光功率的降低和焊接速度的增大而细化和均匀化。     

热处理工艺及Ce对1420铝锂合金焊接接头力学性能的影响

研究了不同热处理状态对不同Ｃｅ含量的１４２０铝锂合金焊接接头力学性能及焊缝凝固组织的影响。结果表明；微量Ｃｅ添加到１４２０合金中，可阻焊缝热影响区的晶粒粗化并使焊缝凝固组织细化。采用焊后固溶＋人工时效的热处理工艺，可使焊接接头强度第数有明显提高。     

2195铝锂合金超声振动辅助搅拌摩擦焊接工艺研究

采用新型超声振动辅助搅拌摩擦焊接设备实现了4 mm厚的2195铝锂合金轧制板的焊接,比较和分析了施加超声对焊缝宏观金相组织、显微硬度与接头拉伸性能的影响,研究了工艺参数对铝锂合金超声振动辅助搅拌摩擦焊缝成形及接头力学性能的影响规律.结果表明:在相同工艺参数条件下,施加超声振动能量能够改善2195铝锂合金搅拌摩擦焊接成形性,促使焊核区塑性材料流动增强,同时减少甚至消除常规搅拌摩擦焊接头内部的孔洞缺陷;在焊缝的上部及中部,由于超声的作用,焊核区的显微硬度得以提高,而焊缝底部变化不大;接头的断口均呈现出韧性断裂模式,施加超声振动能量后的接头的伸长率得以提高,其断口韧窝更加细小均匀;在所研究的工艺参数范围内,接头的最高抗拉强度为282.8 MPa,最大伸长率为11.5％.在转速为600 r/min,焊接速率为225 mm/min条件下,施加超声使接头抗拉强度提高了17.5 MPa,伸长率提高了3.7％.     

快速凝固铝锂合金研究进展

快速凝固铝锂合金是一种低密度、高强度、高弹性模量的引入注目的新型航空航天结构材料。本文概述了快速凝固铝锂合金的特点、基本制备工艺及力学性能，着重综述了提高锂含量，减少氧化物的危害和研制离锆的铝锂合金这三个方面的最新进展，并简要介绍了应用现状和发展前景。     

Microstructure and mechanical properties of laser beam welded Al–Li alloy 2060 with Al–Mg filler wire

Alloy 2060-T8 is a newly developed high-strength Al–Li alloy for applications in aircraft industry. Crack-free welds were obtained in laser beam welding with 5087 filler wire under optimized welding conditions. In this paper, fusion zone microstructure and joint mechanical properties were investigated. Microstructure typical for the weld metal consists of α-Al matrix with a few nanoscale precipitates inside and a coarse icosahedral quasicrystalline T₂ phase at the dendritic and grain boundaries. The quasicrystalline occurred normally in Al–Li–Cu alloys with higher Li contents. Our investigations show that the icosahedral quasicrystalline phase T₂ phase forms in the laser-welded Al–Li alloy 2060 with lower Li content as a result of segregation and replacement of Mg element. The joint tensile strength in as-welded condition is around 317 MPa, about 63% of that of the base metal, and fracture occurs within the fusion zone.     

Al-Li合金真空精炼与成分变化规律的研究

研究了Ａｌ－Ｌｉ合金真空除氢规律，并对比研究了真空除氢过程中化学成分变化规律，为Ａｌ－Ｌｉ合金的生产提供了重要参数，并为研究新一代高韧Ａｌ－Ｌｉ合金打下了基础。     

铝锂合金研究进展

回顾了铝锂合金的发展历史,按时间顺序和性能特点将铝锂合金划分成了三代,并重点介绍了第三代铝锂合金的发展情况,其最引人瞩目的是高强可爆铝锂合金的兴起和低各向异性厚板材的生产,分析认为,第三代铝锂合金的发展趋势是有针对性地提高合金的某方面性能。     

Dispersoids in Al–Li AA8090 series alloys

Chemical composition data of Al3Zr-type dispersoids obtained using the EDAX attached to the transmission electron microscopes in three commercial AA8090 series Al–Li alloys demonstrated the incorporation of Ti in these dispersoids. The extrapolation technique led to the composition of dispersoids to be Al3(Zr0.92Ti0.08). No dispersoids were found other than Al3Zr-type in these alloys although one of the alloys contained Mn. Appearance of Mn-rich dispersoids in one of the re-cast alloys which contained Mn showed that the solubility of Mn in Al is significantly influenced by the Li concentration in Al–Li alloy systems.     

Weldalite049系可焊Al—Li合金研制与应用

在简介介可焊Ａｌ－Ｌｉ合金发展过程的同时，综述了合金微观组织特点及添加元素的作用、焊接性能及冷加工性能，介绍了该合金在航天领域中的几个典型应用。     

金属间化合物Ni3Al基合金结构焊工研究

对Ｎｉ３Ａｌ基合金结构焊接的工艺进行了研究，对焊缝显微组织及性能进行了分析，结果表明：采用合理的焊接工艺参数，用Ｎｉ８１８焊条能够实现Ｎｉ３Ａｌ工个的结构焊接。     

Research and Progress in Laser Welding of Wrought Aluminum Alloys. I. Laser Welding Processes

With the wide application of Al alloys in automotive, aerospace and other industries, laser welding has become a critical joining technique for aluminum alloys. In this review, the research and progress in laser welding of wrought Al alloys have been critically discussed from different perspectives. The primary objective of this review is to understand the influence of welding processes on joint quality and to build up the science base of laser welding for the reliable production of Al alloy joints. Two main types of industrial lasers, carbon dioxide (CO₂) and neodymium-doped yttrium aluminum garnet (Nd:YAG), are currently applied but special attention is paid to Nd:YAG laser welding of 5000 and 6000 series alloys in the keyhole (deep penetration) mode. In this part of the review, the main laser welding processing parameters including the laser-, process-, and material-related variables and their effects on weld quality are examined. In part II of this article in this journal, the metallurgical microstructures and main defects encountered in laser welding of Al alloys such as porosity, cracking, oxide inclusions, and loss of alloying elements are discussed from the point of view of mechanism of their formation, main influencing factors, and remedy measures. In part II, the main mechanical properties such as hardness, tensile, and fatigue strength and formability are also discussed.     

The mechanical properties related to the dominant microstructure in the weld zone of dissimilar formed Al alloy joints by friction stir welding

The joint properties of dissimilar formed Al alloys, cast Al alloy and wrought Al alloy, were examined with various welding conditions. Friction stir welding method could be applied to join dissimilar formed Al alloys which had different mechanical properties without weld zone defects under wide range of welding condition.The weld zone of dissimilar formed Al alloy exhibited the complex structure of the two materials and mainly composed of the retreating side material.The mechanical properties also depended on the dominant microstructure of the weld zone with welding conditions. The different mechanical properties of the weld zone with welding conditions were related to the behavior of the precipitates of wrought Al alloy and Si particles of cast Al alloy. The higher mechanical properties of the weld zone were acquired when a relatively harder material, wrought Al alloy, was fixed at the retreating side.     

高强度低密度大模量菲晶态Ai—Li合金

利用单辊快速凝固装置制备出高强度、低密度、大楼量的非晶态Ａｌ６１Ｌｉ２．５Ｙ２５Ｎｉ１１．５（ｗｔ－％）合金，其最大拉伸断裂强度、显微硬度和弹性模量分别为１０３９ＭＰａ、４８８ＤＰＮ和９８．７ＧＰａ．与同成分的晶态合金相比，具有较高的电极电位、较宽的电压钝化区，其腐蚀抗力为晶态合金的７倍．在恒加热速率的晶化过程中出现４个晶化峰，晶化激活能的计算表明，Ａｌ６１Ｌｉ２．５Ｙ２５Ｎｉ１１．５非晶合金的晶化过程为一级反应．     

Role of plunge depth on the joint formation and mechanical behavior of Al6063-AZ91 dissimilar lap joint produced by friction stir welding

Dissimilar lap joint of Al6063 aluminium and AZ91 magnesium alloys was successfully produced by friction stir welding. Three different plunge depths (3.2 mm, 3.25 mm, and 3.3 mm) were adopted during welding. Similar Al6063–Al6063 lap joints were also produced along with the dissimilar Al6063–AZ91 joints for the purpose of comparing the joint formation. With the increased plunge depth, the width of the similar Al6063 - Al6063 lap joint was increased. On the contrary, joint width was decreased for the dissimilar joint with increased plunge depths. The dissimilar joint was formed with a strong metallurgical bonding between the Al6063 and AZ91 alloys, which is attributed to the mechanical mixing of these alloys in the nugget zone. Additionally, the formation of intermetallics was also observed from the x-ray diffraction analysis. The variations within the measured hardness values were higher at the joint interface due to the mixing of aluminium and magnesium alloys in the nugget zone. From the tensile shear tests, increased strength and decreased elongation were measured with the increased plunge depth. The results demonstrate the importance of the plunge depth on the lap joint formation between dissimilar Al6063–AZ91 alloys during friction stir welding.