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基于铝合金和镀锌钢在熔点上的差异,以ER4043(AlSi5)为填充材料,采用大光斑Nd:YAG激光+MIG电弧复合热源焊接工艺实现两者的熔-钎焊接,研究熔钎焊接头组织和性能。铝合金/镀锌钢板熔钎焊接头分为熔焊接头和钎焊缝两部分,熔焊缝组织由α(Al)等轴晶和晶界上短棒状的Al-Si共晶组织组成,焊趾处的富锌区为α-Al-Zn固溶体和Al-Zn共晶组织。钎焊缝为Fe-Al金属间化合物层,厚度为2~4μm,金属间化合物包括FeAl2、Fe2Al5和Fe4Al13,其中FeAl2和Fe2Al5位于近钢侧的紧密层,而Fe4Al13则呈舌状或锯齿状向熔焊缝内生长。接头抗拉强度随着焊接电流和激光功率的增大呈先增大后减小的趋势,最高可达247.3 MPa。拉伸断裂位置一般位于熔焊缝的熔合区,为以韧性断裂为主的混合断裂。接头内硬度的最大值位于钎焊缝处,然后分别沿着两侧钢板和铝合金熔焊缝逐步降低。 相似文献
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铬青铜与双相不锈钢电子束焊接头组织及形成 总被引:3,自引:0,他引:3
对QCr0.8与1Cr21Ni5Ti的2 mm厚平板试件进行了等厚对中电子束焊接;采用光学显微镜、扫描电镜能谱分析方法对接头区显微组织及成分进行了研究,确定了显微组织构成;根据电子束焊接的特点,建立了QCr0.8与1Cr21Ni5Ti等厚对中电子束焊接接头形成的物理模型,并对接头不均匀组织的形成机制进行了探讨.结果表明:QCr0.8/1Cr21Ni5Ti等厚对中电子束焊接接头显微组织形貌为组织及化学成分极不均匀的Cu(Fe) (α ε)的铸态混合组织,其宏观组织可分为3个区域:显微组织结构相同,均为以Cu(Fe)为主,内有一定数量不均匀弥散分布的α ε相混合组织的焊缝左上部组织区及焊缝底部组织区;以α ε相为主,内有少量弥散分布的Cu(Fe)颗粒混合组织的焊缝中部组织区;接头组织的形成是由接头金属熔化及匙孔形成阶段,接头凝固的初期阶段(析出γ ε相,并形成3个区域),接头凝固的中期阶段(γ ε相结晶完成),接头凝固的后期阶段(形成Cu(Fe)相,焊缝完全变为固态),接头凝固的最终阶段(元素扩散及γ→α相变,形成最终组织)联合作用的结果. 相似文献
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《稀有金属材料与工程》2015,(Z1)
向手工自蔓延焊接燃烧体系中添加Fe O、CaF_2、CaCO_3作为造渣剂,系统研究添加剂对焊渣性质和焊接性能的影响。结果表明,添加剂导致焊条的燃烧速度和反应的绝热燃烧温度降低,其中CaCO_3的作用最为明显。添加剂降低了焊渣的密度和凝固温度,扩大了焊渣的凝固温度范围,促进了焊渣和金属熔池的分离及熔池中气体的排出。每根燃烧型焊条中Fe O、CaF_2、CaCO_3的适宜添加量分别为(0.6~0.8)g、(0.2~0.4)g、(0.4~0.6)g。获得了微观结构为玻璃基体上分布少量富Cu和Fe晶体颗粒的玻璃态焊接熔渣,脱渣性能良好。焊缝合金为以α-Cu固溶体为基体、弥散分布富Fe第二相的纯净金属组织,基本无非金属夹杂,抗拉强度达410 MPa,具有良好的力学性能。 相似文献
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介绍了一种用于战场及野外应急抢修的新型焊接方法-手工自蔓延焊接,以低碳钢为焊接母材,对燃烧型焊条焊药中的高热剂组成、对燃烧速度及焊接质量的影响进行了探讨.结果表明,由Fe2O3 Al系铝热剂和CuO Al系铝热剂组成的高热剂,当CuO Al系含量不低于50%时,焊条燃烧产生足够的热量,实现试板的牢固连接,并达到单面焊双面成形的效果;随CuO Al系含量增加,焊条燃烧速度加快,焊缝抗拉强度降低,CuO Al系含量为50%和60%的焊条,焊条燃烧速度适中,焊接可控性好,且焊缝抗拉强度达420 MPa以上.金相分析表明,富铁第二相的析出对焊缝金属起到强化作用. 相似文献
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The corrosion resistance of a weld has a great impact on the service life of the joint. Changes in welding parameters can cause changes to the heat input, which affect the formation of the weld bead and the precipitation of the second phase, which determines the corrosion resistance of the weld. In this paper, the effect of a change in the welding speed on 2195 aluminium–lithium (Al–Li) alloy joints welded by laser and metal inert gas (laser-MIG) hybrid welding using Al–Si welding wire was studied. The macrostructure and microstructure of the weld were characterized by optical microscopy, X-ray diffraction, and scanning electron microscopy. The results show that the predominant precipitates in the laser-MIG hybrid welded Al–Li alloy were the θ (Al2Cu) and T (Al–Li–Si) phases. As the welding speed increased from 11.5 mm/s to 16.5 mm/s, the heat input decreased, and the amount of the precipitated phase increased. Intergranular corrosion and electrochemical experiments were carried out on the weld seam, and the corrosion resistance was tested. With increasing welding speed, the corrosion resistance of the weld decreased. The high potential of the precipitated phase decreased the corrosion resistance of the weld joint. 相似文献
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等离子弧焊接SiCp/Al基复合材料焊缝“原位”合金化分析 总被引:11,自引:2,他引:11
采用等离子弧焊焊接SiCp/Al基复合材料,以Ar+N2为离子气,并以Ti作为合金化填充材料,研究了焊缝“原位”合金化元素Ti对焊缝显微组织的影响。结果表明,采用焊缝原位合金化方法焊接SiC颗粒增强铝基复合材料(sicp/A1MMCs),可以有效抑制焊缝中针状脆性相Al4C3的形成,并且由于耶的加入,改善了增强相和Al基体之间的润湿性,形成了稳定的熔池,得到以均匀分布的TiN、AlN等为增强相的新型铝基复合材料焊缝,焊接性能得到有效提高。同时还研究了Ti的添加量对焊缝显微组织的影响,结果发现,随着耶含量的增加,焊缝中还生成如Ti5Si3等新的增强相。焊缝“原位”合金化等离子弧焊接是焊接SiCp/Al基复合材料的一种新方法。 相似文献
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《Science & Technology of Welding & Joining》2013,18(8):702-708
AbstractAlthough Ti–6Al–4V alloys show reasonable weldability characteristics, the joint properties are greatly influenced by the welding processes. Microstructures and tensile and impact properties of welded Ti–6Al–4V alloy were evaluated for high vacuum electron beam welding, CO2 laser beam welding and gas tungsten arc welding. The resultant tensile and impact properties of the welded joints are correlated with the weld metal microstructure and hardness. The results indicate that the electron beam welding is more suitable for Ti–6Al–4V sheet welding and the welding seam without defects can be obtained. The full penetration butt welds are obtained by gas tungsten arc welding process, but they have many drawbacks such as wide weld seam, big deformation and coarse grains. Laser beam welding has many advantages such as the narrowest weld seam, the least deformation and the finest grains, but it should be studied again for the reasons of unstable welding technologies and strict condition. 相似文献
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基于自蔓延高温合成技术(SHS技术)和湿法电弧焊原理,研究了一种用于水下金属结构应急维修的新型焊接方法—水下湿法手工自蔓延焊接技术.通过焊条结构设计、焊药设计等,研制了水下燃烧型焊条,进行了焊接试验,对接头组织和性能进行了分析.结果表明,该技术可在无电、无气、无其它设备的条件下实现水下金属构件的湿法焊接,单面焊双面成形,接头抗拉强度达267 MPa,冲击吸收能量13.8 J;SEM和EDS分析表明,焊缝金属为以α-Cu固溶体为基体、有大量块状富铁第二相析出的高铁铜合金,熔合区的成分和组织与焊缝第二相基本相同,焊缝合金与熔融母材交互结晶,形成了梯度熔焊连接;拉伸断裂发生在焊缝或熔合区,断口有大量韧窝,属韧性断裂. 相似文献
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采用Al-Mg及Al—Si两种焊丝分别对SiCp/6061Al复合材料进行了MIG焊及脉冲MIG焊,利用光学显微镜、电子显微镜及MTS-810试验机对焊缝的组织及性能进行了分析。结果表明,采用Al—Mg焊丝焊接时,无论是MIG焊还是脉冲MIG焊,熔池中Al-SiC间的界面反应程度均较大,生成了较多的针状Al4C3,且Al4C3的尺寸较大。采用Al-Si焊丝时,MIG焊熔池中的界面反应程度显著降低,仅生成了少量尺寸较小的针状Al4C3;而采用Al—Si焊丝的脉冲MIG焊焊缝中没有发现针状Al4C3。同时,利用Al—Si焊丝可有效地防止焊缝熄弧处的宏观结晶裂纹。力学性能试验表明,采用同样焊丝时,脉冲MIG焊接头的强度及伸长率比MIG焊接头的高,而用Al-Si焊丝焊接的接头强度比用Al—Mg焊丝焊接的接头强度高。 相似文献
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铝合金/镀锌钢板脉冲MIG电弧熔-钎焊接头组织与性能 总被引:1,自引:0,他引:1
采用数字化脉冲MIG焊机,以ER4043焊丝为填充材料.实现了6013-T4铝合金薄板与镀锌钢板的熔-钎焊接,研究了焊接热输入对接头组织和性能的影响,结果表明,在熔-钎焊接头熔化焊缝焊趾处存在主要由Zn-Al共晶体、富A1的α固溶体和Fe3Al组成的富Zn区:钎焊界面上的Fe-Al金属间化合物层厚度在1.05-4.50μm之间.且随焊接热输入的增加而增大.Fe-Al金属间化合物呈"锯齿"或"舌"状向焊缝内生长,主要为FeAl2,Fe2Al5和Fe4Al13.随着焊接热输入的增大,熔-钎焊接头的抗拉强度先增大而后减小.在850 J/cm的热输入下达到229 MPa,拉伸后在铝合金焊接热影响区发生断裂,为塑韧性断裂;当焊接热输入较小时接头在钎焊界面断裂,属于脆性断裂. 相似文献
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Shouzheng Wei Yajiang Li Juan Wang Kun Liu 《Journal of Materials Engineering and Performance》2014,23(4):1451-1457
Welding of titanium alloy TA15 to aluminum alloy Al 2024 was conducted by pulsed current gas tungsten arc welding using AlSi12 filler metal. Formation process of phases near the Ti/Al interface was discussed. Titanium and aluminum were partially fusion welded in the upper part while brazed together in the middle and bottom parts of the joint. In the upper part of the joint, intermetallics Ti3Al + Ti5Si3, TiAl + Ti5Si3, and TiAl3 were formed as three layers orderly from the titanium side to the weld metal. In the middle and bottom parts of the joint, intermetallics Ti5Si3 and TiAl3 were formed as two layers near the Ti/Al interface. 相似文献