7075铝合金薄板搅拌摩擦点焊接头力学性能研究

采用正交试验法对7075铝合金薄板搅拌摩擦点焊工艺参数进行了优化,分析了点焊接头的成形情况,测试了接头的抗拉强度和焊点的硬度,分析了接头冶金结合面积与最大抗拉载荷之间的关系.结果表明,焊接停留时间对焊点抗拉强度的影响最显著,其次是搅拌头旋转速度,而轴肩下压量的影响最小.焊接工艺参数为:停留时间6s、下压量0.2mam、旋转速度1 500 r/min时,焊点最大抗拉载荷为6.07 kN,焊点表面成形良好,冶金结合程度最佳,焊点硬度分布呈“W”形,热影响区硬度值最低.     

搅拌摩擦点焊机器人无纸化制造控制平台

针对搅拌摩擦点焊机器人无纸化制造控制平台的实现方法进行了研究.采用STEP中性文件几何信息作为设计基础,根据对点焊机器人运动分析,利用OCC搭建了搅拌摩擦点焊机器人无纸化加工平台,以XML文件作为数控加工程序、监控与控制的数据载体.阐明了单个搅拌摩擦点焊机器人加工控制方法.同时,应用面向服务的网络控制框架方法,对搅拌摩擦点焊机器人组的远程控制与监控进行了研究与设计,使得搅拌摩擦点焊机器人焊接加工设计与控制过程更加简单.     

国内外搅拌摩擦点焊的研究进展

搅拌摩擦点焊（FSSW）是在搅拌摩擦焊基础上发展起来的一种新型固相焊接技术,因其接头质量高、缺陷少、绿色节能等众多优点而将成为替代轻合金传统点连接技术的最佳工艺,各国焊接界也纷纷对其开展大量研究工作。本文主要介绍了目前搅拌摩擦点焊最新的焊接方法及原理,并论述了近年来国内外在搅拌摩擦点焊领域的最新研究动态。     

搅拌摩擦点焊

搅拌摩擦点焊(FSSw)是一种最近研究开发出来的新焊接技术.同目前的电阻点焊相比,该方法是具有节能、设备简单、焊点强度高、变形小、焊前表面清理简单,可以焊接厚度差别大的材料,特别适用于高强度铝合金的焊接.重点介绍该技术的基本原理、优缺点、焊接设备,对几种典型铝合金的焊接工艺参数、接头强度和组织等进行了比较详细的分析,从而对该技术有一个全面的了解.     

铝合金搅拌摩擦焊-交叉点焊工艺

在铝合金传统搅拌摩擦点焊的基础上,以提高点焊接头力学性能为目标,提出"搅拌摩擦焊-交叉点焊"技术.其基本工艺原理是,搅拌头沿交叉轨迹做极短距离的往复式搅拌摩擦焊,以实现高性能的点焊连接.对4mm板厚5A02-H14铝合金进行"搅拌摩擦焊-交叉点焊"试验及分析.结果表明,该工艺可大大拓宽点焊接头的连接面积,并显著降低搭接界面畸变和匙孔处材料缺失的不利影响,与传统搅拌摩擦点焊相比,该工艺能够显著提高铝合金点焊接头的抗剪切性能.     

铝合金搅拌摩擦点焊接头力学性能数值模拟

针对铝合金搅拌摩擦点焊工艺,通过实验测试,确定了点焊接头各组织形态和材料属性,建立了接头拉剪力学性能的数值模拟分析模型,获得了拉剪载荷作用下点焊接头的应力分布与变形规律,揭示了接头失效过程.研究结果可为铝合金搅拌摩擦点焊接头拉剪力学性能的分析与评价提供参考.     

AZ31镁合金搅拌摩擦点焊

研究了搅拌头旋转频率以及停留时间对AZ31镁合金搅拌摩擦点焊接头力学性能的影响.随着旋转频率的增大,不同搅拌针条件下,AZ31搅拌摩擦点焊接头的力学性能均呈现先增大后减小的趋势.随着停留时间的延长,AZ31搅拌摩擦点焊接头的力学性能先增大随后在一定范围内波动.结果表明,结合宽度是影响搅拌摩擦点焊接头力学性能的重要因素,...     

LF6铝合金搅拌摩擦点焊

搅拌摩擦点焊(FSSJ)是近年来发明的新的点焊方法,具有接头强度高、能耗低和设备简单等优点,在汽车行业焊接轻质合金如铝合金、镁合金等具有很好的应用前景.采用自行设计的搅拌头对1 mm 1 mm的LF6铝合金进行了搅拌摩擦焊试验研究.试验结果表明,接头剪切强度约是电阻点焊的1.56倍.接头可以分为搅拌区和热影响区,搅拌区的材料受到搅拌头的作用发生圆周运动和轴向运动,形成细小的再结晶晶粒,强度高、塑性好.     

铝合金分步回填无匙孔搅拌摩擦点焊工艺

针对常规搅拌摩擦点焊在焊接过程结束后会留下匙孔的问题,采用了分步回填无匙孔搅拌摩擦点焊的方法对1060铝合金进行搭接焊接试验,以避免产生匙孔,并对在该方法下采用不同转速得到的焊接接头的微观组织及力学性能进行分析。结果表明：在合适的搅拌头转速下,采用分步回填的方法得到的焊接接头表面美观,无毛刺飞边等缺陷,抗剪切能力较强。     

工艺参数对复合搅拌摩擦点焊接头力学性能的影响

采用LF21铝合金研究了复合搅拌摩擦焊时焊接工艺参数(旋转速度、旋转半径)对焊接接头力学性能的影响.结果表明,当其它焊接参数一定时,焊点的力学性能随着搅拌头旋转速度的增加而增加,当搅拌头的旋转速度增加到1 200 r/min时,焊点的剪切力达到最大值为3.47 kN,随着搅拌头旋转速度的进一步增加,焊点的力学性能开始降低.改变旋转半径,焊点的力学性能随着旋转半径的增加而增加,当旋转半径达到0.5 mm时,焊点的剪切力达到最大值为3.47 kN,然后,随着旋转半径的继续增加,焊点的力学性能开始降低.LF21铝合金的复合搅拌摩擦点焊焊点的微观组织与直插式搅拌摩擦点焊不同的是,在塑性环的边上形成了一个由第二层塑性环形成的"耳朵形"区域.     

回填式搅拌摩擦点焊的研究进展

回填式搅拌摩擦点焊技术(RFSSW)是一种新型的固相点焊技术,它既拥有与搅拌摩擦焊(FSW)相同的效率高、能耗少、易操作和污染少等优点,又可消除匙孔,因此在航空、航天和汽车制造领域中有着广阔的应用前景。自发明以来,回填式搅拌摩擦点焊技术已被应用于各种铝合金、镁合金以及异种材料的焊接。文中综述了回填式搅拌摩擦点焊的研究进展,主要涉及回填式搅拌摩擦点焊的基本原理以及回填式搅拌摩擦点焊接头常见的缺陷、显微组织、力学性能,以及同、异种材料的回填式搅拌摩擦点焊工艺等内容,可对实际工程应用中提高回填式搅拌摩擦点焊接头性能以及合理选择回填式搅拌摩擦点焊工艺参数提供一定的借鉴作用。     

Filling technique for keyhole of friction stir spot welding based on the principles of resistance spot welding

Keyhole at the end of a weld prepared by friction stir welding(FSW) is one of the major issues that impede the application of FSW. To address this issue, a keyhole filling technique was proposed in this paper, which is based on the principles of resistance spot welding(RSW). A three-phase secondary rectifier resistance spot welder was applied as the experimental instrument for filling the keyhole in the center of friction stir spot weld(FSSW). The test sheet is a 2024-T4 aluminium alloy with a thickness of 6.0 mm. The experiments results show that the filled joint strength is improved by 26.12% since the area is increased for the plug in the keyhole. And there are two kinds of dimples in the tensile fracture—equiaxial dimples and long dimples. The filled joint involves the fusion welding zone(FWZ), pressure welding zone(PWZ), melted plug zone(MPZ), and plastic deformation zone(PDZ). The FWZ and the PWZ is the melting bond and diffusion bond between the plug and keyhole, respectively. The MPZ is the center part and the PDZ is upper or lower part of the plug.     

铝合金搅拌摩擦点焊的研究现状与发展

介绍了国内外搅拌摩擦点焊最新的焊接方法,以及各种方法的原理及优缺点.国内外研究表明,搅拌摩擦点焊可以很好地焊接铝合金,其接头性能优于电阻点焊.搅拌摩擦点焊的方法有很多,各有优缺点,需要根据具体的情况进行选用.搅拌摩擦点焊的工艺参数对性能影响较大,每个参数都有最佳范嗣,需要综合进行考虑.并对搅拌摩擦点焊的发展趋势进行了分析.     

Review on underwater friction stir welding: A variant of friction stir welding with great potential of improving joint properties

Friction stir welding (FSW) is a solid-state welding process which is capable of joining materials which are relatively difficult to be welded by fusion welding process. Further, this process is highly energy-efficient and environmental-friendly as compared to the fusion welding. Despite several advantages of FSW over fusion welding, the thermal cycles involved in FSW cause softening in joints generally in heat-treatable aluminum alloys (AAs) due to the dissolution or coarsening of the strengthening precipitates leading to decrease in mechanical properties. Underwater friction stir welding (UFSW) can be a process of choice to overcome these limitations. This process is suitable for alloys that are sensitive to heating during the welding and is widely used for heat-treatable AAs. The purpose of this article is to provide comprehensive literature review on current status and development of UFSW and its importance in comparison to FSW with an aim to discuss and summarize different aspects of UFSW. Specific attention is given to basic principle including material flow, temperature generation, process parameters, microstructure and mechanical properties. From the review, it is concluded that UFSW is an improved method compared with FSW for improving joint strength. Academicians, researchers and practitioners would be benefitted from this article as it compiles significantly important knowledge pertaining to UFSW.     

无匙孔搅拌摩擦点焊组织及剥离性能研究

针对2 mm的6082-T6铝合金薄板以搭接的方式进行无匙孔搅拌摩擦点焊,研究了工艺参数对剥离性能的影响规律,观察分析接头的金相组织和断口,并对接头进行了显微硬度的测试。通过正交工艺试验来确定无匙孔搅拌摩擦点焊十字搭接接头的最优工艺参数,研究结果表明:焊接接头的横截面宏观形貌呈瓢状,从焊接接头中心到母材,其金相显微组织可分为搅拌区、轴肩区和母材区;点焊接头的抗剥离载荷在最优工艺参数下可达5.24 kN;断口的断裂形式为韧性断裂。     

Repair welding process of friction stir welding groove defect

The groove defect formed in the friction stir welding dramatically deteriorates weld appearances and mechanical properties of the joints owing to its larger size and penetration. Therefore, the friction stir repair welding was utilized to remove such a groove defect, and the focus was placed on the mechanical properties and microstructural characteristics of the repair joints so as to obtain an optimum repair welding process. The experimental results indicate that the groove defect can be removed by friction stir repair welding, and the offset repair welding process is superior to the symmetrical repair welding process. In the symmetrical repair welding process, a large number of fine cavity defects and an obvious aggregation of hard-brittle phase Al2Cu occur, accordingly the mechanical properties of the repair joint are weakened, and the fracture feature of repair joint is partially brittle and partially plastic. A good-quality repair joint can be obtained by the offset repair welding process, and the repair joint is fractured near the interface between the weld nugget zone and thermal-mechanically affected zone.     

AZ31B镁合金/镀锌钢无匙孔搅拌摩擦点焊结合方式

采用无匙孔搅拌摩擦点焊和真空扩散焊对AZ31B镁合金和DP600镀锌钢板进行搭接点焊试验,利用扫描电镜、能谱仪及拉伸试验对无匙孔搅拌摩擦点焊接头与真空扩散焊接头进行微观组织及力学性能的对比分析.结果表明,镁钢无匙孔搅拌摩擦点焊接头结合方式为机械结合与冶金结合共同作用,冶金结合表现为:镁钢界面发生扩散生成由Mg、Fe、O形成的金属间化合物,镁合金中的合金元素与铁生成金属间化合物,机械结合表现为:钢像“钉子”一样插入到镁合金基体中,且在镁钢结合界面处,两种金属呈锯齿状咬合,接头抗剪切载荷平均可达10.36 kN,而只存在单纯扩散结合方式的真空扩散焊接头抗剪切载荷平均仅为2.5 kN.通过两种接头对比分析可知,机械结合对接头力学性能的贡献远远大于冶金结合,其接头结合方式以机械结合为主.     

ABS塑料与6082铝合金搅拌摩擦点焊工艺及机理

针对2 mm厚的ABS塑料板和6082-T6铝合金进行搅拌摩擦点焊可焊性试验,并将成形较好的试件的横截面的形貌进行了观察分析,并对其进行力学性能的测试.结果表明,将铝合金板放在上,塑料板放在下的搭接方式可以实现良好的连接;最优工艺参数为搅拌头旋转速度为400 r/min,焊接时间为30 s,所得焊接接头的抗拉剪载荷最大为3.31 kN;点焊接头有两种断裂模式.