5083铝合金搅拌摩擦焊接头组织及力学性能研究

采用搅拌摩擦焊焊接5083铝合金,光学显微镜OM、透射电镜TEM对焊接接头进行金相分析,拉伸试验和硬度试验对焊接接头力学性能进行分析.结果表明,焊接接头焊核区为晶粒细小的等轴晶组织,热力影响区晶粒细小且沿剪切方向拉长,热影响区晶粒明显长大.其接头的力学性能显著优于传统的熔化焊,抗拉强度约为母材的90％,塑性与母材相当;...     

6061-T6铝合金薄板的搅拌摩擦焊接

采用搅拌摩擦焊(FSW)技术对1 mm厚6061-T6铝合金薄板进行了对接.研究了焊接工艺参数的范围,实验测试了焊接接头的强度、硬度和延伸率,利用金相显微镜、扫描电镜和透射电镜分析了接头的微观组织.结果表明:对于1 mm厚度6061-T6铝合金,FSW的最优工艺参数为旋转速度1 800 r·min^-1,焊接速度1000 mm·min^-1;在此参数下,接头的硬度值达到母材的80%左右,抗拉强度达到母材的103%,延伸率达到母材的54%;接头的力学性能与微观结构相符.     

搅拌头转速对6063铝合金双面搅拌摩擦焊接头组织与性能的影响

采用光学显微镜和拉伸试验机,研究了搅拌头转速对6063-T4铝合金挤压材双面搅拌摩擦焊接头显微组织与力学性能的影响.结果表明,随着搅拌头转速的增加,焊接接头的热输入量增大,焊核区和热影响区的晶粒尺寸增大,焊接接头的强度逐渐下降.搅拌头转速为1000rpm时,焊接接头的强度最高,抗拉强度为132.2MPa,屈服强度为78...     

挤压态6060-T5和铸态6061铝合金异种搅拌摩擦焊接头组织及力学性能研究

采用搅拌摩擦焊焊接挤压态6060-T5和铸态6061铝合金板材,在不同的焊接工艺下,对焊接接头的微观组织及力学性能进行研究。结果表明：焊接速度过快会在焊接表面形成少许毛刺,影响表面质量,但焊接接头均没有明显缺陷,焊核区微观组织还能得到显著细化。焊接接头硬度略低于同种铝合金焊接接头硬度,且受两种材料混合影响,焊核区硬度值波动较大。接头抗拉强度随着焊接速度的增大而提高,且均保留了较好的拉伸变形能力,断裂方式是韧-脆混合型。     

搅拌摩擦修复6061-T4铝合金裂纹的 组织和性能

采用搅拌摩擦方法对预制裂纹的6061-T4铝合金板进行修复,研究了表面裂纹和贯穿裂纹2种类型试样修复区的微观金相组织和抗拉性能及硬度分布.结果表明: 2种预制裂纹试样在合适的焊接工艺参数下,经搅拌摩擦修复后裂纹都能愈合.修复区晶粒由于动态再结晶,晶粒细化形成细小的等轴晶粒,裂纹修复后的试样抗拉强度能达到母材强度的78 %,表面裂纹试样的伸长率达到16.1 %、贯穿裂纹试样伸长率达到14.2 %,为韧性断裂;裂纹修复区的显微硬度的分布曲线基本呈现“W”形.      

焊后时效对6061-T6铝合金搅拌摩擦焊接头的影响

对4组6061-T6铝合金搅拌摩擦焊接头进行焊后人工时效处理,采用OM,SEM等分析了时效处理工艺对接头的组织和力学性能的影响规律和机制。研究表明:焊缝截面形貌呈现典型的3个区,时效处理后,焊缝区晶粒形貌无显著变化,晶界较自然时效清晰,晶内析出相也明显增多;接头强度和显微硬度随人工时效处理时间的延长而提高,提高幅度随保温时间逐渐减小;时效处理为8 h时接头力学性能优良,接头抗拉强度均达到265 MPa以上,约为母材的93.0%;焊核区硬度达到90 HV,约为母材的90%。时效处理中,焊接过程中固溶在基体中的第二相粒子析出,形成弥散强化效应,大幅提高接头的强度和硬度。随着时效时间的延长,析出粒子逐渐较少,强化效应逐渐减弱;接头最薄弱的区均位于后退侧的热机械影响区,其最低硬度值约为母材的75%。拉伸断口均与拉伸方向成约45°角,断口平整,呈典型的切断断口形貌,与自然时效接头的断口形貌相比,时效处理后接头的断口韧窝大而浅,塑性稍有降低。     

2519铝合金搅拌摩擦焊焊缝组织与性能

2519是第三代新型高强装甲铝合金,开发与之配食的成熟焊接技术。特别是厚板焊接技术,是其实现工程应用的前提。本文采用搅拌摩擦焊工艺对2519合金厚板进行了实验研究,实现了25mm厚的2519铝合金焊接。并对焊缝组织进行了组织、力学性能、抗应力腐蚀性能测试,结果表明：抗拉强度达到300MPa以上,延伸率达到8—10％。     

搅拌摩擦加工参数对5083铝合金组织性能的影响

采用搅拌摩擦加工方法对不同焊接参数下的退火态5083铝合金的组织和性能进行研究.通过显微硬度实验研究了硬度在前进侧和后退侧以及加工区上下部分的分布规律;通过金相观察研究了加工区表面带状纹理和腐蚀后观察到的弧纹之间的关系.对母材和加工区用扫描电镜观察了析出相的形貌、尺寸及分布规律.结果表明:高硬度区宽度随着轴肩直径的增大而增大,随着转速和焊速之比(ω/ν)的增加而增大,硬度在前进侧(AS)和后退侧(RS)的分布是不均匀的;从母材到加工区硬度逐渐上升,RS侧的上升速度约为AS侧的一半.     

焊接旋转速度对搅拌摩擦焊接头性能的影响

以地铁侧墙产品(板厚3.5mm)为实验对象,考察在相同搅拌头、焊接速度、下压量的前提下,改变搅拌头的旋转速度对接头力学性能的影响.通过对焊后试件进行外观、低倍、拉伸、弯曲、硬度检测的实验数据进行对比,结果表明,在旋转速度为1400r/min时,其接头力学性能最佳.     

对搅拌摩擦焊T型2014-T651航空铝合金的微观组织的研究

在这篇文章中,对搅拌摩擦焊(FSW)T型2014-T651铝合金的微观组织进行了研究。通过光学显微镜(OM),X射线衍射(XRD)和In-situXRD对材料的微观组织进行了观察,并且采用了适当热处理参数进行了对比。结果表明,搅拌区(SZ)由于发生了再结晶受热处理影响最为敏感,热处理后SZ区域所有晶粒尺寸增大,并且织构有序化明显。热处理后第二相在SZ区域沿晶界析出,然而在BM/TMAZ/HAZ区域均匀析出。     

Microstructure of the Joint of 1565chM Alloy Sheets Fabricated by Friction Stir Welding

The microstructure in the joints of a non-heat-treatable aluminum–magnesium 1565chM alloy sheets fabricated by friction stir welding is studied. The structure near the interface between the base metal and a welded joint is examined. Friction stir welding results in a gradient structure with ultrafine grains at the center of the welded joint. The structure in the welded joint forms by the mechanism resulting in the formation of a layered ultrafine structure due to plastic deformation by shear and rotation of structural fragments. Layers are assumed to form due to the balance between the strain hardening and the softening caused by frictional heating and heat released during deformation. An analogy between the microstructure in the joint fabricated by friction stir welding and the microstructure formed by sliding friction is drawn.     

Effect of Process Parameters on Microstructure and Mechanical Properties in Friction Stir Welding of Aluminum Alloy

Friction stir welding process is a promising solid state joining process with the potential to join low melting point materials, particularly aluminum alloys. The most attractive reason for this is the avoidance of solidification defects formed during conventional fusion welding processes. Tool rotational speed and the welding speed play a major role in deciding the weld quality. In the present work an effort has been made to study the effect of the tool rotational speed and welding speed on mechanical and metallurgical properties of friction stir welded joints of aluminum alloy AA6082-T651. The micro hardness profiles obtained on welded zone indicate uniform distribution of grains in the stir zone. The maximum tensile strength obtained is 263 MPa which is about 85% of that of base metal. Scanning electron microscope was used to show the fractured surfaces of tensile tested specimens.     

镁合金搅拌摩擦焊接技术

对5mm厚镁合金AZ31B板材的摩擦焊接技术进行了试验研究，结果表明：适合其板材的搅拌摩擦焊接的搅拌头，材料为W6MoSCr4V2高速钢，结构为凹面圆台形，根部直径5．5mm，端部直径为2．5mm，轴肩尺寸为12mm，长度为4．7mm。镁合金搅拌摩擦焊接头的抗拉强度可达母材的90％，延伸率可达母材的50％。搅拌摩擦焊接头焊合区为动态再结晶组织，在接头前进边焊合区与母材有明显的分界线，返回边过渡区有金属微熔的迹象。     

Microstructure and Fatigue Properties of a Friction Stir Lap Welded Magnesium Alloy

Friction stir welding (FSW), being an enabling solid-state joining technology, can be suitably applied for the assembly of lightweight magnesium (Mg) alloys. In this investigation, friction stir lap welded (FSLWed) joints of AZ31B-H24 Mg alloy were characterized in terms of the welding defects, microstructure, hardness, and fatigue properties at various combinations of tool rotational rates and welding speeds. It was observed that the hardness decreased from the base metal (BM) to the stir zone (SZ) across the heat-affected zone (HAZ) and thermomechanically affected zone (TMAZ). The lowest value of hardness appeared in the SZ. With increasing tool rotational rate or decreasing welding speed, the average hardness in the SZ decreased owing to increasing grain size, and a Hall–Petch-type relationship was established. Fatigue fracture of the lap welds always occurred at the interface between the SZ and TMAZ on the advancing side where a larger hooking defect was present (in comparison with the retreating side). The welding parameters had a significant influence on the hook height and the subsequent fatigue life. A relatively “cold” weld, conducted at a rotational rate of 1000 rpm and welding speed of 20 mm/s, gave rise to almost complete elimination of the hooking defect, thus considerably (over two orders of magnitude) improving the fatigue life. Fatigue crack propagation was basically characterized by the formation of fatigue striations concomitantly with secondary cracks.     

稀土镁合金搅拌摩擦焊接接头组织及性能分析

成功实现了7 mm厚Mg-Gd-Y系镁合金板的搅拌摩擦焊接,用光学电子显微镜、扫描电子显微镜等手段对焊接接头进行分析。实验结果表明:接头表面光滑,没有裂纹。显微组织特征显示接头有明显分区,各区域晶粒度存在差异。在旋转速度为800 r·min-1,焊接速度为100 mm·min-1时,可以获得较好的焊接性能,抗拉强度达到母材的87%,断后伸长率达到母材的84%。焊缝显微硬度的最低值出现在前进侧机械热影响区,断口表现为准解理断裂特征,断口剖面局部可见镁与稀土元素Gd和Y形成的形状规则、颗粒细小的第二相粒子。     

The Microstructure,Texture and Mechanical Properties of Friction Stir Welded Aluminum Alloy

Russian Journal of Non-Ferrous Metals - The microstructure and texture of 7075-T6 FSW weld with optimal parameters are investigated using optical microscopy, electron back scatter diffraction and...     

铝锂合金搅拌摩擦焊接热循环

搅拌摩擦焊接过程中，焊件上任一位置于搅拌头行走到该位置所在垂直于焊缝直线的瞬间，热循环温度达到最大值，并随着搅拌头远离而迅速降低。焊缝起点受搅拌头扎入行为的影响，而焊缝终点受搅拌头提起行为的影响，二者经受的热循环温度低于焊缝其它部位。然而焊缝起点和终点间的材料经受稳定的热循环作用。焊缝中心经受的焊接热循环温度最高，为415℃。焊缝两侧材料经受不同的热循环作用，前进侧略高于后退侧7～12℃。     

搅拌摩擦焊用钨铼合金的研究进展

搅拌摩擦焊接技术是一种环保、低成本的固相连接技术,已经在航空航天、轨道交通和新能源汽车等领域得到广泛应用。对于高熔点合金材料如钛合金和不锈钢的搅拌摩擦焊接而言,搅拌头材料成了主要制约因素。钨铼（W-Re）合金凭借其高熔点、高硬度和强抗腐蚀性等优点,已成为研究和应用最热的搅拌摩擦焊接高熔点合金的搅拌头材料。本文综述了近年来在搅拌摩擦焊工艺中以W-Re合金作为搅拌头材料的制备方法、复合强化技术和应用场景的研究进展。此外,还展望了拓宽W-Re合金在搅拌摩擦焊领域应用的前景,包括降低W-Re合金的生产成本和提高其服役寿命等方面,旨在推动W-Re合金搅拌头材料在搅拌摩擦焊领域的进一步应用和发展。     

Mechanical Properties,Microstructure and Crystallographic Texture of Magnesium AZ91-D Alloy Welded by Friction Stir Welding (FSW)

The objective of the study was to characterize the properties of a magnesium alloy welded by friction stir welding. The results led to a better understanding of the relationship between this process and the microstructure and anisotropic properties of alloy materials. Welding principally leads to a large reduction in grain size in welded zones due to the phenomenon of dynamic recrystallization. The most remarkable observation was that crystallographic textures appeared from a base metal without texture in two zones: the thermo-mechanically affected and stir-welded zones. The latter zone has the peculiarity of possessing a marked texture with two components on the basal plane and the pyramidal plane. These characteristics disappeared in the thermo-mechanically affected zone (TMAZ), which had only one component following the basal plane. These modifications have been explained by the nature of the plastic deformation in these zones, which occurs at a moderate temperature in the TMAZ and high temperature in the SWZ.     

Friction Stir Welded AZ31 Magnesium Alloy: Microstructure, Texture, and Tensile Properties

This study was aimed at characterizing the microstructure, texture and tensile properties of a friction stir welded AZ31B-H24 Mg alloy with varying tool rotational rates and welding speeds. Friction stir welding (FSW) resulted in the presence of recrystallized grains and the relevant drop in hardness in the stir zone (SZ). The base alloy contained a strong crystallographic texture with basal planes (0002) largely parallel to the rolling sheet surface and $ \langle {11\bar{2}0} \rangle $ directions aligned in the rolling direction (RD). After FSW the basal planes in the SZ were slightly tilted toward the TD determined from the sheet normal direction (or top surface) and also slightly inclined toward the RD determined from the transverse direction (or cross section) due to the intense shear plastic flow near the pin surface. The prismatic planes $ (10\bar{1}0) $ and pyramidal planes $ (10\bar{1}1) $ formed fiber textures. After FSW both the strength and ductility of the AZ31B-H24 Mg alloy decreased with a joint efficiency in-between about 75 and 82 pct due to the changes in both grain structure and texture, which also weakened the strain rate dependence of tensile properties. The welding speed and rotational rate exhibited a stronger effect on the YS than the UTS. Despite the lower ductility, strain-hardening exponent and hardening capacity, a higher YS was obtained at a higher welding speed and lower rotational rate mainly due to the smaller recrystallized grains in the SZ arising from the lower heat input.