采用非夹层液相扩散焊连接铝基复合材料

采用真空扩散焊焊接铝基复合材料ＳｉＣｗ／６０６１Ａｌ通过系列试验研究了焊接工艺参数对接头强度的影响。结果表明：该材料扩散焊时,焊接温度是影响接头强度的主要工艺参数,当焊接温度介于基体铝合金液－固两相温度区间时,接合面上出现了液态基体金属,可获得较高的接头强度。     

铝基复合材料SiCW/6061Al的激光焊接

采用脉冲激光焊接工艺研究铝基复合材料SiCw/6061Al的焊接性,着重探讨激光输出功率（P）、脉冲频率（f) 对接头性能的影响,借助X射线衍射、扫描电镜、透射电镜等手段分析接头组织。研究发现,焊缝中存在的界面反应物、气孔缺陷,是导致该种材料焊接性显著降低的主要因素。进一步研究表明,在激光焊接条件下铝基复合材料界面反应是不可避免的,反应物沿热流方向生成,具有一定的方向性,激光输出功率是影响SiC-Al界面反应的主要因素,同时提高脉冲频率将对界面反应有一定的抑制作用;焊缝中气孔随激光脉冲频率的增大而减少直至消失。在此基础上,通过制定合理的焊接工艺,获得了成形良好的铝基复合材料激光焊焊缝。     

Microstructure and Strength of Laser Welds of Sub-micron Particulate-reinforced Aluminum Martix Composite Al2O3p/6061Al

The microstructure of laser welds of sub-micron particulate-reinforced aluminum matrix composite Al2O3p/6061Al and the weldability of the material were studied.Experimental results indicated that because of the huge specific surface area of the reinforcement,the interfacial reaction between the matrix and the reinforcement was restrained intensively at elevated temperature and pulsed laser beam.The main factor affecting the weldability of the composite was the reinforcement segregation in the weld resulting from the push of the liquid/solid interface during the solidification of the molten pool.The laser pulse frequency directly affected the reinforcement segregation and the reinforcement distribution in the weld,so that the weldability of the composite could be improved by increasing the laser pulse frequency.On the bases of this,a satisfactory welded joint of sub-micron particulate-reinforced aluminum matrix composite Al2Op/6061Al was obtained by using appropriate welding parameters.     

Microstructure and Strength of Laser Welds of Sub-micron Particulate-reinforced Aluminum Matrix Composite Al_2O_(3p)/6061Al

The special microstrUctUre of sub--micronaluminum matrix composites makes it dimcultto obtain a sa1isfactory welded joint l l--3]. Up tonow, there is no report abollt the systCm1c studyon the we1dability of the composites.T'he microstructure of laser welds of sub-mi-cron particulate-reintbrced aluminum matrixcomposite Al=O,/606lAl was analyzed bymeans of X--ray diffrac1ion, SFM and TEM, thewelding mechanism of the composite was stu-died, and the approach to improve the propertiesof the we…     

AGE STRENGTHENING OF DIFFUSION WELDED JOINT OF Al_2O_(3p)/6061Al COMPOSITE

1.IntroductionAluminummatrixcompositehascometobeusedforvariouskindsofstructUreowingtoitsexcellentpropertiessuchashighspecificstrength,highspecificmodule,highwearability,andbecomeemphasisanddirectionofresearchinnewmaterialsscience.ButthespecialcompositionsOfaluminummatrixcompositealsodetendnethecharacteristicthatitishardtobesubjecttosecondalworking,especiallytheweldingtechnologyproblemisamajorfactorhinderingitfurthertodevelOP.Thestudyondiffusionweldingtechnologyforaluminummatrixcompositeshowe…     

Diffusion bonding mechanism and microstructure of welded joint of aluminium matrix composite Al_2O_(3p),/6061

1INTRODUCTI0NAluminiummatrixcomp0site,thankstoitsoutstandingphysicalandmechanicalperfor-mance,hasattractedgreatattenti0nsfrommate-rialscientistsbothathomeandabroad.Especial-lytheparticlereinforcedaluminiummatrixcom-posites,c0st-effective,isotr0pical,wear-resis-tantandflexiblewithfunctionaldesign,havewideapplicationsinaerospaceandaviationstruc-turalcomponents.t.[1~6].Thestudy0nthewe1dabilityofaluminiummatrixcomp0sitesandweldingtechniqueisfarfromenough,comparedwiththeremarkableachievementson…     

铝基复合材料扩散焊接接合区微连接行为

以铝基合材料Al2O3p/6061Al为对象,对该种材料扩散焊接接合区微连接行为进行了探索性的研究,分析了接头微观组织及力学性能。研究表明,扩散焊接温度对接合区的微连接行为有显著影响,当焊接温度低于铝基复合材料固相线温度时,增强相-基体、增强相-增强相之间微连接属弱连接;当焊接温度介于该种材料液、固两相温度区间时,接头区域出现液态基体金属,增强相-基体之间可以实现较好结合,同时液态金属对增强相-增强相接触部位进行渗透,使增强相-增强相接触转化为增强相-基体-增强相结合,在此基础上发现在铝基复合材料液、固两相温度区有“临界温度”存在,为成功实现该种材料扩散连接奠定理论基础。     

Diffusion welding process and joint''''s microstructure behavior of SiC_w/6061Al composite

The rules such as process parameters affecting joint properties and the evolution principle of weld's microstructure have been researched by adopting diffusion welding process to connect SiCw/6061Al composite. Experimental results show that there exists a critical temperature region between solid and liquid phase line of SiCw/6061 Al composite, and the region will shrink with the increasing of welding pressure. When diffusion welding occurred under the critical temperature region, welding joint exhibits bad property of bonding, and the matrix and the reinforcement can't bond effectively. When diffusion welding occurred in the critical temperature region, the strength of welding joint changes widely with the variation of welding temperature. When welding temperature varies in 10癈, the strength of welding joint will change obviously. Only when welding temperature is higher than the critical temperature region, stable joint properties can be obtained. Simultaneously the matrix and the reinforcement has bet     

Al2O3p/6061Al复合材料焊接工艺参数的优化及接头组织

通过与基体铝合金的对比试验研究了颗粒增强铝基复合材料Ａｌ２Ｏ３ｐ／６０６１Ａｌ扩散焊各主要工艺参数对接头强度的影响规律,探讨了接头区域微观组织状态对接头强度的影响。结果表明：焊接温度是影响接头强度的主要工艺参数,接头区域存在氧化物及增强相偏聚等缺陷,是造成该种材料焊接性差的主要原因,在此基础上成功实现了颗粒增强铝基复合材料Ａｌ２Ｏ３ｐ／６０６１Ａｌ的扩散连接。     

亚微米级Al2O3p/6061Al铝基复合材料扩散焊接工艺

以亚微米级Al2O3p/6061 Al铝基复合材料为对象,研究了直接扩散焊与采用中间层扩散焊两种工艺焊接铝基复合材料的特点、机理,分析了中间层对接头强度的影响规律.结果表明,在铝基复合材料液、固温度区间,存在"临界温度区域",在此温度区域进行直接扩散焊接时,通过液相基体金属的浸润,使得在扩散接合面中增强相-增强相接触转化为增强相-基体-增强相的有机结合,获得高质量焊接接头;进一步研究发现,在扩散接合面上采用合适的基体中间层同样可以将增强相-增强相接触转化为增强相-基体-增强相的有机结合,同时增大"临界温度区域"范围,接头性能更加稳定,接头变形量进一步减小(＜2%).     

低真空条件下铝基复合材料扩散焊接工艺

以Al2O3p/6061Al铝基复台材科为对象．研究了在低真空条件下的直接扩散焊接和6061Al铝箔作为中间层的扩散焊接工艺。分析了焊接温度．保温时间与不同焊接工艺所得接头微观组织及强度的关系。同时．分析了低真空度和夹具对接头性能的影响。试验结果表明．两种焊接工艺所得接头强度随温度变化的规律以600℃和640℃为界分为三个阶段．并且随保温时间的延长有所提高。在较高的温度下．压力和液态金属的作用促使氧化膜破碎,有利于接头强度的提高。     

STUDY ON DIFFUSION WELDING OF ALUMINIUN MATRIX COMPOSITE

1.IntroductionAluminummatrixcomposite,thankstoitsexcellentcomprehensivepropertiessuchashighspecificstrength,highspecificmodule,resistancetoelevatedtemperature,resistancetoradiationandgooddimensionalstability,hasattractedgreatattentionfIDmmaterialscientistsbothhomeandaboard.Asoneofsubstitutesofconventionalmetals,alundniummatrixcompositeshavebeenwidelyaPPliedinthefieldsofaerospace,aviationandautomobile~lufacturingindustries,andbecomesmainsubjectinresearchanddevelopmentofmetalmatrixcomPOsites.A…     

Study on diffusion welding parameters of particle-reinforced aluminium matrix composite Al2O3p/6061Al

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Predicting effects of diffusion welding parameters on welded joint properties by artificial neural network

1　ＩＮＴＲＯＤＵＣＴＩＯＮＭｅｔａｌｍａｔｒｉｘｃｏｍｐｏｓｉｔｅｓ (ＭＭＣｓ) ,ｄｕｅｔｏｔｈｅｉｒｏｕｔｓｔａｎｄｉｎｇｐｒｏｐｅｒｔｉｅｓｓｕｃｈａｓｈｉｇｈｓｐｅｃｉｆｉｃｓｔｒｅｎｇｔｈ ,ｓｐｅｃｉｆｉｃｍｏｄｕｌｕｓ ,ｓｉｚｅｓｔａｂｉｌｉｔｙ ,ｈｉｇｈ ｔｅｍｐｅｒａｔｕｒｅ ｒｅｓｉｓｔａｎｔａｎｄｃｏｓｍｉｃ ｒａｙｒｅｓｉｓｔａｎｔ ,ａｒｅｗｉｄｅｌｙｕｓｅｄｉｎａｅｒｏｓｐａｃｅ ,ａｖｉａｔｉｏｎａｎｄｅｌｅｃｔｒｏｎｆｉｅｌｄｓ ,ａｎｄｂｅｃｏｍｅｔｈｅｍａｊｏｒｄｅｖｅｌ…     

铝/铜异种金属电阻热辅助超声波缝焊工艺特性

1060纯铝箔作为中间层,通过电阻热辅助超声波缝焊的方式实现1 mm厚度6061铝合金和T2紫铜异种金属焊接,分析了焊接过程中电阻热对铝/铜焊接接头焊缝成形、界面形貌、温度场以及力学性能的影响. 结果表明,采用单独超声波缝焊焊接铝/铜异种金属时,因产生的焊接能量较小,接头连接界面处仅局部区域位置形成连接,接头拉剪强度为45 MPa. 但在电阻热辅助超声波缝焊过程中,电阻热的加入能够有效预热工件,令待焊材料表面发生软化,在高频振动作用下,接头连接界面处形成有效连接. 同时,引入电阻热提高了铝/铜界面处温度,由单独超声波缝焊的140 ℃增加至190 ℃,界面处原子扩散距离增加,获得焊接接头的拉剪强度增加至75 MPa,相对前者接头拉剪强度提高67%.     

Be/Al/Be激光焊接接头显微组织分析

铝为过渡材料,运用激光焊接技术实现了铍与铍激光熔焊连接.采用扫描电镜(SEM)、金相显微镜(OM)、微控电子万能试验压力机及微区X射线衍射仪(XRD)对焊接接头的显微组织、剪切断口形貌、力学性能及相结构进行了试验研究.结果表明,Be/Al/Be激光焊接接头为铝与铍形成类似复合材料的双相组织,接头抗剪强度介于铝和铍的抗剪强度之间,随着焊缝组织铍含量增加,接头抗剪强度呈上升趋势、焊接接头断裂形式由塑性断裂向脆性断裂转变、断口形貌由韧窝断口向准解理断口过渡,焊缝中的金属化合物是导致焊缝失效断裂的主要原因.     

Influence of In Situ Reaction on the Microstructure of SiC<Subscript>p</Subscript>/AlSi7Mg Welded by Nd:YAG Laser with Ti Filler

The effect of in situ reaction on the microstructure of Nd:YAG laser welded joints of aluminum matrix composite SiC_p/AlSi7Mg was studied. Results showed that the laser welding with Ti filler improved the tensile strength of welded joints. Moreover, the laser welding with in situ reaction effectively restrained the pernicious Al₄C₃ forming reaction in the interface between aluminum matrix and reinforcement particles. Simultaneously, the reaction-formed TiC phase distributed uniformly in the weld. This permitted SiC_p/AlSi7Mg composite to be successfully welded by Nd:YAG laser.     

2219-T651铝合金激光摆动焊接接头微观组织和力学性能

采用激光摆动焊接技术对2219-T651铝合金进行了不同摆动幅度和频率下的焊接试验,研究了摆动工艺参数、焊缝气孔率和宏观成形、接头组织和性能之间的内在联系.结果表明,与无摆动焊接相比,激光摆动焊接可以降低焊缝气孔率,尤其随着摆动幅度的增加,当摆动幅度为2.5 mm时,气孔率降至1.66%.与母材相比,热影响区和熔化区发生软化.靠近焊缝的热影响区,由于沉淀强化作用的变弱,硬度逐渐降低,直至出现“平台”.而由α(Al)基体以及枝晶间和晶界α(Al)+θ(Al₂Cu)共晶相组成的熔化区,因铜的偏析导致固溶强化效果被削弱,表现出最低的硬度.此外,部分摆动参数下焊缝晶粒尺寸有所细化,这引起了其硬度的略微升高.当摆动频率为150 Hz和摆动幅度为2.5 mm时,接头的抗拉强度高达318 MPa,约为母材抗拉强度的69.4%,接头抗拉强度与断口孔洞面积占比呈线性负相关关系,焊缝气孔率是影响焊态接头抗拉强度的主要因素.     

铝合金振动焊接过程非线性时间序列模型分析

针对7系列超硬铝在传统熔焊过程中易出现热裂纹、气孔和焊接接头软化等问题,研究振动焊接工艺过程中,焊接工艺参数变化与焊接接头强度间的非线性关系机理,建立基于焊接过程工艺参数测量数据的7075超硬铝振动焊接接头强度非线性时间序列预测模型. 文中在7075超硬铝振动焊接过程参数测量数据的基础上,建立了焊接过程参数时间序列,并在此基础上研究建立了焊接过程系统相空间重构参数及确定性检验方法. 根据重构相空间的相点演化轨迹与焊接接头强度参数间的非线性关系,建立相空间相点演化轨迹的人工神经网络拟合模型,对焊接接头的断后伸长率、抗拉强度、硬度、焊缝余高、晶枝最大粗度、晶粒数量等物理参数进行计算. 根据建立的模型进行的一系列焊接接头强度试验显示. 结果表明,该模型的预测结果可以满足工程需要,具有工程实用价值.     

Study on behavior of reinforcement in molten pool for submicron composite Al_2O_3p/6061 Al during laser welding

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