基于田口法的高硅铝合金超高旋转速度搅拌摩擦焊接工艺优化

超高旋转速度搅拌摩擦焊借助超高旋转速度摩擦热量实现了薄板高硅铝合金的连接,这一方法大大降低了搅拌摩擦焊接的轴向力,减小了焊接变形,对焊接薄板铝合金具有独特的优势。文中以焊缝成形质量和焊接接头抗拉强度作为响应值,基于田口法对影响焊接质量的主要焊接工艺参数(旋转速度、焊接速度和下压量)进行试验设计,优化高硅铝合金超高旋转速度搅拌摩擦焊工艺。结果表明,焊接速度和下压量是显著影响因素,最优焊接工艺参数焊接速度为60 cm/min,旋转速度为14 000 r/min,下压量为1.8 mm。这一工艺条件下高硅铝合金超高旋转速度搅拌摩擦焊接接头的最大抗拉强度为129 MPa,达到母材高硅铝合金抗拉强度的97%。     

基于田口法的高硅铝合金超高旋转速度搅拌摩擦焊接工艺优化

超高旋转速度搅拌摩擦焊借助超高旋转速度摩擦热量实现了薄板高硅铝合金的连接,这一方法大大降低了搅拌摩擦焊接的轴向力,减小了焊接变形,对焊接薄板铝合金具有独特的优势。文中以焊缝成形质量和焊接接头抗拉强度作为响应值,基于田口法对影响焊接质量的主要焊接工艺参数(旋转速度、焊接速度和下压量)进行试验设计,优化高硅铝合金超高旋转速度搅拌摩擦焊工艺。结果表明,焊接速度和下压量是显著影响因素,最优焊接工艺参数焊接速度为60 cm/min,旋转速度为14 000 r/min,下压量为1.8 mm。这一工艺条件下高硅铝合金超高旋转速度搅拌摩擦焊接接头的最大抗拉强度为129 MPa,达到母材高硅铝合金抗拉强度的97%。     

2A97铝锂合金搅拌摩擦焊

文中采用不同搅拌摩擦焊接工艺参数对2A97铝锂合金的可焊性进行了研究.结果显示,接头抗拉强度和断后伸长率随搅拌头转速的提高而降低,随焊接速度的提高先增后减.在旋转频率为600 r/min,焊接速度200 mm/min时接头抗拉强度最高达到373 MPa,为母材的69%.FSW接头拉伸试验断口位置基本都发生在焊核(NZ)区.焊核区和热力影响区中沉淀相大部分溶解,只有少数存留,热力影响区沉淀相密度高于焊核区.     

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。     

机床用铝合金/不锈钢的异质搅拌摩擦焊工艺

采用不同工艺参数下的搅拌摩擦焊对接焊方法,进行了机床用6063铝合金/304L不锈钢的异质焊接试验,并进行了接头的X光无损检测以及显微组织和力学性能测试。结果表明,搅拌头旋转速度500~650 r/min、焊接速度155~185 mm/min时可获得良好的焊接接头;接头抗拉强度可达139 MPa,达到6063铝合金母材抗拉强度的67%,达到304L不锈钢母材抗拉强度的17%。搅拌头旋转速度优选550 r/min、焊接速度优选180 mm/min。     

7075铝合金搅拌摩擦焊接头组织与力学性能研究

利用搅拌摩擦焊方法对7075铝合金板进行焊接,探讨了焊接速度和搅拌头旋转速度等焊接工艺参数对焊缝成形及接头力学性能的影响,并对焊接接头的显微组织进行了分析.结果表明:采用搅拌摩擦焊焊接7075铝合金时,焊接接头具有较好抗拉性能.当旋转速度为750r/min、焊接速度为95 mm/min时,焊接接头的强度最高,达到母材抗拉强度(487 MPa)的97.4％,并且其伸长率也较高(为3.1％);当旋转速度为950 r/min、焊接速度为150 mm/min时焊接接头的伸长率最好,为4.7％.总体上看,焊接接头的伸长率和母材相比较低.     

基于正交试验的2024-T4铝合金超声辅助搅拌摩擦焊的研究

采用正交试验研究了超声辅助搅拌摩擦焊工艺参数对1.8 mm厚的2024-T4铝合金板接头组织与力学性能的影响。结果表明:焊接速度对接头抗拉强度的影响最大,而旋转速度和超声频率的作用依次减弱;采用最优参数焊接,即当转速为1600 r/min、焊速为240 mm/min、频率为25 k Hz时,其接头的抗拉强度可达397 MPa,比搅拌摩擦焊强度提高了6%。通过对比焊缝宏观及微观纹理、力学性能、金相组织和显微硬度等,均发现超声搅拌摩擦焊焊缝性能要优于搅拌摩擦焊。     

AZ91D薄板搅拌摩擦焊

实现了厚度为2.2 mm铸造镁合金AZ91D薄板的搅拌摩擦焊和钨极氩弧焊,分析了搅拌摩擦焊工艺参数对焊接接头成形的影响和接头组织变化,考察了搅拌摩擦焊接头的力学性能.在搅拌头旋转速度为1 380 r/min时得到了比较理想的焊接接头,而1 960 r/min的转速过大.接头不同区域所受的机械力和热量不同,显微组织明显不同.搅拌区晶粒细小,显微硬度和强度都有所提高.搅拌摩擦焊接头力学性能与热输入有关;与氩弧焊接头相比,搅拌摩擦焊接接头的性能更好.     

84 mm厚6082铝合金型材搅拌摩擦焊双面焊工艺研究

采用搅拌摩擦焊双面焊工艺,对84 mm大厚板6082-T4铝合金型材对接接头进行了焊接,获得表面成形美观、光亮、无隧道孔和未熔合缺陷的焊接接头。应用光学显微镜、显微硬度仪及电子拉伸试验机等对搅拌摩擦焊接头组织与性能进行研究。试验结果表明,在焊接旋转速度为400 r/min,焊接速度为150 mm/min的工艺参数条件下,接头的抗拉强度达到217 MPa;接头断裂位置开始于焊缝前进侧热影响区与热力影响区的结合处;接头显微硬度最低值出现在双面焊重合区,为HV54。     

搅拌摩擦焊工艺对AZ31合金组织性能的影响

研究了焊接速度、搅拌头转速对AZ31合金搅拌摩擦焊接头显微组织和力学性能的影响,分析了焊接工艺参数的作用机理。结果表明,焊接速度过低(250 mm/min)或者搅拌头转速过高(650、700 r/min),焊核区的条带区中都会产生孔洞缺陷。随着焊接速度的增加,焊核区和热影响区的晶粒尺寸都呈现逐渐减小的趋势,合金的抗拉强度和断后伸长率都表现为先升高后降低的趋势。随着搅拌头转速的增加,焊核区和热影响区的晶粒尺寸都呈现逐渐增加的趋势,合金的抗拉强度和断后伸长率呈现先增加后减小的趋势。AZ31合金适宜的搅拌摩擦焊工艺为焊接速度400 r/min、搅拌头转速550 r/min,此时搅拌摩擦焊接头的抗拉强度和断后伸长率分别为202 MPa和5.0%,断裂位置位于后退侧热影响区。     

Influences of process parameters on tensile strength of friction stir welded cast A319 aluminium alloy joints

Fusion welding of cast A319 (Al-Si-Cu) alloy will lead to many problems including porosity, micro-fissuring, and hot cracking. Friction Stir Welding (FSW) can be used to weld A319 alloy without these defects. In this investigation, an attempt has been made to study the effect of FSW process parameters on the tensile strength of A319 alloy welded joints. Joints were made using different combinations of tool rotation speed, welding speed, and axial force, each at four levels. The quality of weld zone was analyzed using macrostructure and microstructure analysis. Tensile strength of the joints were evaluated and correlated with the weld zone microstructure. The joint fabricated with a 1200 rpm tool rotation speed, 40 mm/min welding speed, and 4 kN axial force showed superior tensile strength compared with the other joints.     

Optimisation of friction stir welding process parameters to weld cast aluminium alloy A413 – an experimental approach

Abstract

A413 is a high strength eutectic aluminium silicon cast alloy used in the food, chemical, marine, electrical and automotive industries. Fusion welding of these cast alloys can lead to problems such as porosity, microfissuring and hot cracking, etc. However, friction stir welding can be used to weld these cast alloys effectively, without defects. In this investigation, an attempt was made to optimise the friction stir welding process parameters for joining the cast aluminium alloy A413. Joints were made using four levels each of tool rotation speed, welding speed and axial force. The quality of the weld zone was analysed using macrostructure and microstructure analysis. Tensile strength of the joints were evaluated and correlated with the weld zone hardness and microstructure. The joint fabricated using a tool rotation speed of 900 rev min^?1, a welding speed of 75 mm min^?1 and an axial force of 3 kN showed the best tensile strength.     

Multi-objective optimization of friction stir welding parameters using desirability approach to join Al/SiCp metal matrix composites

Silicon carbide particulate (SiC_p) reinforced cast aluminium (Al) based metal matrix composites (MMCs) have gained wide acceptance in the fabrication of light weight structures requiring high specific strength, high temperature capability and good wear resistance. Friction stir welding (FSW) process parameters play major role in deciding the performance of welded joints. The ultimate tensile strength, notch tensile strength and weld nugget hardness of friction stir butt welded joints of cast Al/SiC_p MMCs (AA6061 with 20% (volume fraction) of SiC_p) were investigated. The relationships between the FSW process parameters (rotational speed, welding speed and axial force) and the responses (ultimate tensile strength, notch tensile strength and weld nugget hardness) were established. The optimal welding parameters to maximize the mechanical properties were identified by using desirability approach. From this investigation, it is found that the joints fabricated with the tool rotational speed of 1370 r/min, welding speed of 88.9 mm/min, and axial force of 9.6 kN yield the maximum ultimate tensile strength, notch tensile strength and hardness of 265 MPa, 201 MPa and HV114, respectively.     

6061铝合金FSW接头与MIG焊接头对比试验

采用搅拌摩擦焊(FSW)和MIG焊分别对6061铝合金板进行了焊接试验,测试了焊接接头的强度,观察了焊接接头的金相组织,并进行了接头的硬度分布测试.结果表明,搅拌摩擦焊接头抗拉强度高达212.05 MPa,是母材抗拉强度的86％,比MIG焊的接头强度略高.焊接接头软化区宽度比MIG焊接头软化宽度窄.6061铝合金母材为典型的轧制组织,焊核区为细小的等轴晶组织,MIG焊接头焊缝为柱状晶组织.     

ZL114A铸铝搅拌摩擦焊接头性能

研究了采用不同焊接参数时ZL114A铸铝搅拌摩擦焊接头的金相组织、硬度分布及力学性能。结果表明，ZL114A铸铝的搅拌摩擦焊焊接性良好。焊核区的微观组织是无方向性的、细小的等轴晶粒。细化的硅粒子均匀布满整个焊核区。与粗大的树枝状母材相比，焊核晶粒细小、均匀而致密，没有观察到气孔等缺陷。焊缝区硬度分布较母材稳定，变化范围小。随着焊速增加，硅粒子所占体积比逐渐下降。热一机械影响区晶粒被拉长。接头的力学性能与焊接参数的匹配有关系。采用高焊速及转速与焊速比在3左右，获得的接头抗拉强度可达到母材的91％。焊后经T6热处理，可与同炉热处理母材等强。     

Optimizing friction stir welding parameters to maximize tensile strength of AA2219 aluminum alloy joints

AA2219 aluminium alloy (Al-Cu-Mn alloy) has gathered wide acceptance in the fabrication of lightweight structures requiring a high strength-to-weight ratio and good corrosion resistance. In contrast to the fusion welding processes that are routinely used for joining structural aluminium alloys, the friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force etc., and the tool pin profile play a major role in determining the joint strength. An attempt has been made here to develop a mathematical model to predict the tensile strength of friction stir welded AA2219 aluminium alloy by incorporating FSW process parameters. A central composite design with four factors and five levels has been used to minimize the number of experimental conditions. The response surface method (RSM) has been used to develop the model. The developed mathematical model has been optimized using the Hooke and Jeeves search technique to maximize the tensile strength of the friction stir welded AA2219 aluminium alloy joints.     

DH36钢水下摩擦塞焊工艺及力学性能

文中通过工艺试验研究了DH36钢水下摩擦塞焊工艺窗口及焊接接头的显微组织和力学性能。结果表明,在焊接转速较低时,焊接接头根部容易形成“未结合”焊接缺陷,提高焊接转速可有效避免缺陷的形成;焊接转速为7500r/min、轴向压力在30~45kN范围是较适宜的焊接工艺参数;焊接接头焊缝组织主要为板条马氏体和贝氏体,焊接热影响区的组织主要为贝氏体;焊接接头的拉伸性能和冲击性能均随焊接转速的提高有不同程度升高,但随轴向压力的变化不具有明显规律性;在较优的焊接工艺参数下（焊接转速7500r/min、轴向压力40kN）焊接接头屈服强度为370MPa,抗拉强度为530MPa,断后伸长率为22.5%,结合线处0℃冲击吸收功为42.5J。     

Influence of Processing Parameters on Induced Energy, Mechanical and Corrosion Properties of FSW Butt Joint of 7475 AA

Friction stir welding (FSW), a promising solid state joining process invented at TWI in 1991, was used to join 9?mm thick 7475 aluminum alloy which is considered essentially unweldable by fusion processes. In the present work, the process parameters such as tool rotational speed were varied from 300 to 1000?rpm for a travel speed of 50?mm/min and the influence of process parameters in terms of energy input on microstructure, hardness, tensile strength, and the corrosion property of 7475 aluminum joints was evaluated and analyzed. The maximum tensile strength of FSW joints was obtained at rotational speed of 400?rpm and traverse speed of 50?mm/min (59.2?kJ) which attributed maximum stirred zone area and maximum hardness. The maximum corrosion resistance properties of weld in 3.5% NaCl solution, however, were obtained at rotational speed of 1000?rpm and traverse speed of 50?mm/min. Furthermore, for a given weld, stirred zone showed improved corrosion properties than TMAZ.