采用搅拌摩擦焊方法制备的非晶增强铝基复合材料的微观组织分析

利用金相、EDS、XRD及TEM试验等对采用源于搅拌摩擦焊方法的搅拌摩擦加工技术制备的非晶增强铝基复合材料的微观组织结构进行试验分析.结果表明,非晶增强体与基体5A06铝合金经过搅拌摩擦加工过程充分的搅拌作用,获得了层状混和组织结构.复合材料中存在大量的90~400 nm纳米级组织,主要由-αA l与-αA l非晶组织构成.纳米级组织的存在有助于复合材料性能的提高,而非晶结构的存在表明非晶增强体在搅拌摩擦加工过程中并未完全晶化.     

搅拌摩擦焊接工艺参数对AA6061-B4C焊接接头抗拉强度的影响（英文）

搅拌摩擦焊(FSW)是一种固态连接技术,可用来连接高强度铝合金及多种陶瓷颗粒增强金属基复合材料(MMCs)。搅拌摩擦焊获得的陶瓷增强金属基复合材料焊缝优良,在增强体与基体间没有发生有害反应。对搅拌摩擦焊接工艺参数对AA6061-B4C焊接接头抗拉强度的影响进行研究。采用4因素5水平的中心复合设计来控制实验的次数。构建一数学模型来分析搅拌摩擦焊工艺参数对接头抗拉强度的影响。结果表明,在旋转速度1000r/min、焊接速度1.3mm/s、轴向力10kN、增强相含量12%的条件下,搅拌摩擦焊得到的焊接接头的抗拉强度最大。根据构建的模型采用广义简约梯度算法进行优化以得到最大的抗拉强度。金相分析表明,在焊接接头中出现了多种区域,如焊合区、热力影响区和热影响区。在焊合区观察到大量的被细化的铝基体晶粒以及粒径明显减小的B4C颗粒。在热力影响区出现塑性变形、热影响和被拉长的铝晶粒。     

外加热源对铝-铜搅拌摩擦焊对接的影响

为了改善铝-铜搅拌摩擦焊对接接头的焊缝接头性能,文中采用对焊缝铜一侧引入外加热源的方法,来增加焊接热输入,提高铜侧材料的软化程度.结果表明,外加热源能够有效提高焊缝部位铜一侧的焊接温度,从而增加焊接过程中铜一侧的塑化流动性,形成成形良好的焊接接头.通过焊缝的物相对比可知,外加热源引起的温度场的改变,有效地减少了焊缝中CuAl,CuAl₂等中间相的含量,增加了铜颗粒在焊缝中的含量.在力学性能上表现为有外加热源的焊缝拉伸强度较高,显微硬度分布均匀.     

影响搅拌摩擦焊金属塑性流动的因素

针对LF6/LD10、12／T2研究了搅拌摩擦焊(FSW)的金属塑性流动。通过工艺试验，分析了影响FSW金属塑性流动的因素。研究结果表明，被焊材料反复动态再结晶是其持续塑跬流动的前提条件。影响金属塑性流动的因素主要有两个——材料的变形温度和变形速率。搅拌工具使材料保持高应变速率，并对材料快速加热，致使层错能很高的铝发生动态再结晶，促使其稳定流动。保持一定的焊接温度有利于金属动态软化，促进塑性流动，实现焊接。     

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.     

Friction stir welding of 25%SiC/2124Al composite with optimal mechanical properties and minimal tool wear

In this research, 8-mm-thick plates of 25%SiC/2124Al composite have been joined successfully by using an un-threaded WC–Co tool which showed minimal tool wear. Decreasing the rotational and advancing speeds is a key factor to obtain successful joints. Defect-free welds, and a joint efficiency (100UTS_joint/UTS_BaseMaterial) of up to 97%, can be achieved if a high forge force, F_z, (above some 15?kN) is reached. Proportionality between the torque, M, and F_z is observed. High F_z values, and corresponding M, lead to high values of the total energy per unit length of weld, H_tot, supplied by the tool to the workpiece. It is proposed that most of this energy is spent in plastic deformation of the high strength composite.     

7075铝合金与H68黄铜的搅拌摩擦焊组织分析

采用金相显微镜对7075铝合金与H68黄铜异种材料搅拌摩擦焊接头组织进行观察、采用X射线衍射仪（XRD）对焊接接头中相结构进行分析,并采用显微硬度计对焊接接头硬度分布进行测试.结果表明,搅拌针的旋转频率为1 100 r/min,焊接速度为80 mm/min时,焊接接头未形成金属间化合物,焊核区晶粒细化,且显微硬度值增加...     

颗粒增强汽车用铝基复合材料的搅拌摩擦焊接

对SiC颗粒增强铝基复合材料进行搅拌摩擦焊接,研究了焊接转速和焊接速度对焊接接头组织和力学性能的影响。结果表明,焊接速度为200 mm/min时,焊接转速对SiCp/Al搅拌摩擦焊接接头抗拉强度影响不大。在焊接转速1000 rpm时,随着焊接速度的增加,SiCp/Al搅拌摩擦焊接接头热影响区最低硬度提高,抗拉强度逐渐增加。焊接速度大于300 mm/min时,SiCp/Al搅拌摩擦焊接接头抗拉强度相差不大。     

CuNiCrSi铜合金搅拌摩擦焊工艺参数与组织性能分析

为了探究CuNiCrSi铜合金搅拌摩擦焊工艺参数与组织性能,采用正交试验法对工艺参数进行优化,并研究了焊缝的组织性能及材料流动性. 结果表明,焊接速度是对焊接过程影响最为显著的因素,试验得到焊接最佳工艺参数组合,在最优参数组合下焊缝的抗拉强度为491.4 MPa,达到母材抗拉强度的84.7%. 当焊接速度过大时会在焊缝的前进侧出现隧道型缺陷;材料的流动可以分为四部分;前进侧材料流动情况比返回侧复杂;焊接速度过小时表面会出现毛刺;母材区粗大的粒子为铬和硅的偏聚物,而镍无偏聚均匀地分布在材料中;焊核区晶粒随着焊接速度的增加而变小. 最优参数下焊核区晶粒虽然细小均匀,但硬度却比母材区低.     

工艺参数对铝镁搅拌摩擦焊焊缝成形质量的影响

工艺参数对铝镁异种材料搅拌摩擦焊接头质量有着重要影响,研究了焊接速度,搅拌头旋转频率,材料放置位置,搅拌头正反转及偏移等工艺参数对7075铝合金与AZ31B热挤压态镁合金异种材料搅拌摩擦焊对接接头成形质量的影响.结果表明,在搅拌针旋转频率为13 r/s,焊接速度为30 mm/min下可获得较好的焊缝成形质量;另外,要获...     

搅拌摩擦焊修复ZL210铸造铝合金组织与性能分析

鉴于铸件中存在不可避免的缺陷,以ZL210合金为研究对象,对搅拌摩擦焊修复技术进行试验研究,重点分析转速对修复接头微观形貌和力学性能的影响. 结果表明,当转速过低时,修复区容易出现孔洞缺陷;在合理的焊接参数组合下可得到无缺陷的焊核区,其由细小的等轴晶组成. 修复区的显微硬度呈“W”分布,热影响区的宽度随转速增加而增加. 另外,随着转速的增加,修复区的抗拉强度先增加后减小;当转速为1 500 r/min,修复区的抗拉强度和断后伸长率达到最大值,分别为318 MPa和11.8%. 断裂形貌表明修复后材料呈现典型的韧性断裂.     

搅拌摩擦焊工艺参数窗口的建立与接头性能

搅拌摩擦焊的工艺参数对焊缝的表面成形和接头性能有着决定性的影响.以3mm铝合金2024板材对接焊为代表,通过大量的工艺参数试验,考查了多种焊接参数组合下的焊接接头质量,并在此基础上建立了工艺参数窗口.结果表明,在转速375～475r/min,焊接速度150～235mm/min的工艺参数窗口内,接头可以获得母材80%以上的抗拉强度.通过对拉伸断口的显微分析,发现靠搅拌区上方的材料塑性较好,搅拌区底部材料抗变形能力较差,接头区沿厚度方向分层严重.     

Comparison of 2A12 aluminium alloy joint by ultrasonic assisted friction stir welding and friction stir welding

Ultrasonic assisted friction stir welding （UAFSW） is a recent modification of conventional friction stir welding, which adds ultrasonic energy directly into the friction stir welding area by the pin. In this study, 2A12 aluminum alloy was welded by this process and conventional, respectively. The tensile tests, microstructure and fracture surface of FSW joint and UAFSW joint were analyzed. The research results show that the surface forming texture of ultrasonic assisted friction stir welding joint, compared with conventional, is finer and more uniform, showing metallic matte color. The grains are much finer in weld nugget zone, thermo-mechanically affected zone and heat-affected zone; S-phase particles size is much smaller and distribution is more homogeneous in the matrix. The tensile strength of UAFSW joint is 94. 13% of base metal, and the elongation is 11.77%. The tensile strength of FSW joint is 83.15% of base metal, and the elongation is 8.81%. The tests results reveal that ultrasonic vibration can improve the tensile strength and the elongation of welded joints.     

搅拌摩擦焊应用及焊接设备简介

介绍了搅拌摩擦焊的工艺过程，分析了搅拌摩擦焊焊缝及焊接过程的优缺点。对搅拌摩擦焊的应用和常用搅拌摩擦焊设备作了简要的描述。     

基于不旋转轴肩的铝镁异种材料搅拌摩擦焊

焊具是搅拌摩擦焊的核心,对焊接质量起至关重要的作用. 利用不旋转轴肩焊接系统对6061-T6铝和AZ31B镁合金进行连接,重点分析传统和不旋转轴肩焊接系统下接头成形和力学性能等. 结果表明,与传统工艺相比,采用不旋转轴肩工艺的接头表面成形更加光滑,焊核区以典型铝镁混合的叠层结构为主,且铝镁冶金结合界面呈弯曲状,有效地增强了铝镁异种材料的机械咬合效果;焊缝区金属间化合物层明显减小,其主要是由不旋转轴肩增强焊核区材料的搅拌效果并起到“热沉”的作用所致. 采用不旋转轴肩的接头最大抗拉强度为137 MPa,较传统工艺提高了28%.     

异种材料及复合热源搅拌摩擦焊

在对接和搭接方式中,异种材料搅拌摩擦焊相较于同种材料分别具有一些额外的焊接参数,并且对搅拌头材料也有更苛刻的使用要求。总结近年来异种材料搅拌摩擦焊的研究现状,介绍异种材料搅拌摩擦焊过程中脆性金属间化合物的生成及其对焊接接头的力学性能产生的影响。从金属流动机理和数值模拟方面,研究金属间化合物的生成和成长规律,给出针对金属间化合物可能的解决方法。针对高熔点焊材,介绍复合热源搅拌摩擦焊技术、常用的辅助热源以及复合热源搅拌摩擦焊在异种材料搅拌摩擦焊方面的优点和研究的不足之处。     

SiCp/6061Al复合材料等离子弧焊工艺参数对焊缝组织及性能的影响

采用等离子弧焊接工艺研究铝基复合材料SiCp/6061Al的焊接性,借助X射线衍射、扫描电镜等手段分析接头组织,着重探讨了在填加和不填加合金化填充材料Ti的情况下,焊接电流、焊接速度对焊缝显微组织及焊接接头力学性能的影响机理,研究表明,在未填加材料Ti时,焊接工艺参数的改变并不能抑制有害相Al4C3的生成,只能改变其尺寸和数量;在填加填充材料Ti时,焊缝熔池中增强相的种类及分布是影响焊接接头性能的主要因素;适当调整焊接工艺参数有利于焊缝中心形成完全以新生颗粒TiC,TiN和AlN为增强相的完全原位反应区;同时减小新旧增强相共存区域的宽度,并消除增强相SiC颗粒的偏聚现象,从而提高了焊接接头的力学性能.     

高密度聚丙烯板半自动化机器人搅拌摩擦焊接参数优化

采用搅拌摩擦焊可进行热塑性材料的连接,通过搅拌头和工件间摩擦产生的焦耳热得以实现。相对于搅拌摩擦焊接的热塑性塑料,传统工具会在所焊接试样的背面产生一道焊缝,该焊缝会在根部形成缺陷,从而降低整个试件的抗拉强度。选用的高密度聚乙烯板具有高透明度,能够实时分析其在焊接过程中产生的形态变化。设置焊接参数为:探头自身旋转速度800~1 200 r/min,横向行进速度40~200 mm/min,轴向力1~5 k N。此外,还分别选用高度为5 mm的方形、柱形及具有一定角度的探头对试样进行焊接,最终通过检验焊缝处抗拉强度和观察微观结构来评估焊缝质量。     

Process parameters optimization for friction stir welding of RDE-40 aluminium alloy using Taguchi technique

Taguchi approach was applied to determine the most influential control factors which will yield better tensile strength of the joints of friction stir welded RDE-40 aluminium alloy. In order to evaluate the effect of process parameters such as tool rotational speed, traverse speed and axial force on tensile strength of friction stir welded RDE-40 aluminium alloy, Taguchi parametric design and optimization approach was used. Through the Taguchi parametric design approach, the optimum levels of process parameters were determined. The results indicate that the rotational speed, welding speed and axial force are the significant parameters in deciding the tensile strength of the joint. The predicted optimal value of tensile strength of friction stir welded RDE-40 aluminium alloy is 303 MPa. The results were confirmed by further experiments.     

紫铜的搅拌摩擦焊接头性能测试与组织分析

对T2紫铜的搅拌摩擦焊技术进行了实验研究,对其基本工艺、接头组织和性能等进行了初步分析.实验结果表明,用搅拌摩擦焊方法焊接6mm厚的T2紫铜板,当焊接规范合适时,可得到成形美观、内部无缺陷、几乎不变形的平板对接接头;搅拌摩擦焊接头的抗拉强度可达母材的90%;搅拌摩擦焊接头的电阻率与母材基本相同.