共查询到19条相似文献,搜索用时 234 毫秒
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《中国有色金属学报》2017,(6)
采用电阻点焊对铝合金与低碳钢进行焊接,分析了接合界面区反应层形貌及分布等显微组织特征。结果表明:在接合界面上观察到反应物层的生成,其厚度随位置的变化而变化;界面反应物是由靠近铝合金侧的反应物为FeAl_3和靠近钢侧反应物为Fe_2Al_5构成;FeAl_3的生成归结于其生成自由能较低,而Fe_2Al_5的生长主要因其结构上在c轴方向存有大量Al原子空位而造成的各向异性扩散。 相似文献
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Sn-58Bi无Pb焊料与化学镀Ni-P层之间的界面反应 总被引:1,自引:1,他引:1
研究了Sn-58Bi共晶焊料与Cu的界面反应以及在Cu基体上化学镀Ni-P层的界面反应.焊接温度为180℃,焊接后时效温度范围为60-120℃,时间为5-30d.利用SEM,EDAX,XRD对反应产物进行了鉴定.结果表明,焊料与Cu的界面反应产物为Cu6Sn5,与化学镀Ni-P层的界面反应产物为Ni3Sn4,在Ni3Sn4与Ni-P层之间存在一层富P层.在同样条件下,Cu6Sn5的生长速度要快于Ni3Sn4的速度.化学镀Ni-P层中P含量较高时进一步抑制Ni/Sn界面反应生成Ni3Sn4的速度.界面金属间化合物层生长动力学符合x=(kt)^1/2关系,表明界面反应由扩散机制控制.由实验结果计算,Cu6sn5的表观激活能为90.87kJ/mol;Ni3Sn4的表观激活能则与化学镀Ni-P层中P含量有关,当镀层P含量为9%与16%(原子分数)时,其表观激活能分别是101.43kJ/mol与117.31kJ/mol. 相似文献
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针对铝/钢难以焊接这一课题,研发了基于复合电极的电阻点焊新工艺,并对铝合金A6061与低碳钢Q235进行了点焊. 介绍了复合电极的设计、制造流程,观察分析了结合界面区反应层形貌及分布等微观组织特点,探讨了焊接电流对熔核尺寸和接头抗剪载荷的影响. 在结合界面上观察到了反应层的生成,其厚度随位置的变化而变化. 焊接接头熔核直径与抗剪载荷随焊接电流的增加而增大. 结果表明,在铝合金与低碳钢的电阻点焊中,镶嵌式复合电极的使用能够起到抑制界面反应层在焊点中央区域生长的效果. 相似文献
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Dissimilar joints of copper to aluminium were produced by high power ultrasonic welding (USW). The interfacial reaction between copper and 6061 aluminium alloy as a function of welding time was studied. The intermetallic compound (IMC) layer is mainly composed of CuAl2 and Cu9Al4. The thickness of the IMC layer increases with the welding time. For a relatively long welding time (0·7 s) in USW, the dendritic solidification microstructure was observed in local regions, owing to the occurrence of the eutectic reaction, α-Al+θ→L, in the welding process. The lap shear load (or strength) of the joints first increases and then decreases with increasing welding time, and the failure of the joints occurred dominantly at the interface. This is mainly attributed to the development of IMC layer at the interface. 相似文献
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Ranfeng Qiu Chihiro Iwamoto Shinobu Satonaka 《Journal of Materials Processing Technology》2009,209(8):4186-4193
We joined aluminum alloy A5052 to cold-rolled steel SPCC (Steel Plate Cold Commercial) and austenitic stainless steel SUS304 using resistance spot welding with a cover plate. The interfacial microstructure was observed using transmission electron microscopy. A thick two-layered reaction layer contains Fe2Al5 and FeAl3 and a thin serration reaction layer contains Fe2Al5 and FeAl3 were observed at the A5052/SPCC and A5052/SUS304 interface, respectively. Mechanical property analysis suggested that the reaction layer has no effect on the tensile shear strength of the A5052/SUS304 joint and that the tensile shear strength of the A5052/SPCC joint is influenced by the reaction layer formed at its interface. 相似文献
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以ER4043铝硅焊丝为填充金属,研究了Q235钢螺柱与7A52铝合金板CMT焊接工艺,在焊接电流115~135 A,电弧电压14.5~16.5 V,焊接速度0.3 m/min条件下,焊接过程稳定,焊缝成形连续美观.结果表明,7A52铝合金侧熔合区界面为熔焊特征,铝母材发生熔合,熔合良好;钢螺柱侧熔合区为钎焊特征,界面存在反应层,由靠近钢螺柱的Fe2Al5层和靠近焊缝侧的FeAl3层组成,整体反应层厚度由根趾向焊趾方向逐渐减小.焊趾部位出现富镍区,主要由Al3Ni的共晶组织及少量Al3Ni2组成.与无镀镍层焊缝比较表明,镀镍层在焊接过程的行为降低了界面反应层厚度,且通过形成富镍区,降低了接头的脆性,使接头抗剪切强度提高了15%~19%,最高达到146.9 MPa,满足了高强铝合金螺柱焊接的质量要求. 相似文献
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SiCp/2024 matrix composites reinforced with SiC particles and 2219 aluminum alloy were joined via centered electron beam welding and deflection beam welding, respectively, and the microstructures and mechanical properties of these joints were investigated. The results revealed that SiC particle segregation was more likely during centered electron beam welding (than during deflection beam welding), and strong interface reactions led to the formation of many Al4C3 brittle intermetallic compounds. Moreover, the tensile strength of the joints was 104 MPa. The interface reaction was restrained via deflection electron beam welding, and only a few Al4C3 intermetallic compounds formed at the top of the joint and heat affected zone of SiCp/Al. Quasi-cleavage fracture occurred at the interface reaction layer of the base metal. Both methods yielded a hardness transition zone near the SiCp/2024 fusion zone,and the brittle intermetallic Al4C3compounds formed in this zone resulted in high hardness. 相似文献
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分别采用电子束对中焊、偏束焊技术,研究了Si C颗粒增强铝基复合材料Si Cp/2024与2219铝合金的接头组织及力学性能.结果表明,对中焊时接头易出现Si C增强相的偏聚,同时发生严重的界面反应,生成大量脆性相Al4C3,接头抗拉强度最高为104 MPa.采用偏束焊工艺可以很好地抑制界面反应,通常只在焊缝上部与Si Cp/Al热影响区上部生成少量脆性相Al4C3,接头抗拉强度最高可达131 MPa.试件均断裂在母材界面反应层上,且为明显的脆性断裂.不同工艺下接头横截面硬度分布存在突变区,该区域在Si Cp/2024熔合区附近,该处脆性相Al4C3的生成导致硬度升高. 相似文献
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Don-Hyun Choi Byung-Wook Ahn Chang-Yong Lee Yun-Mo Yeon Keun Song Seung-Boo Jung 《Intermetallics》2011,19(2):125-130
The spot welding of Al plate to Mg plate was produced by friction stir spot welding using various tool rotation speed and duration time of the tool to investigate the effects of the welding parameters on the reaction of Al and Mg alloy. The interface microstructure and phase were investigated using optical microscopy, scanning electron microscopy and X-ray diffraction. The mechanical properties of the joints are evaluated using tensile test. Experimental results show that intermetallic compounds were formed in the interface of the Al and Mg alloys. The thickness of intermetallic compounds layer increases with increasing tool rotation speed and duration time, and has a significant effect on the strengths of the joints. Heavy thickness of intermetallic compounds layer seriously deteriorates the mechanical properties of the joints. The intermetallic compounds layer mainly contains Al3Mg2 and Al12Mg17 相似文献
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用Ag-Cu-Ti钎料钎焊SiCw/Al2O3复合陶瓷和金属时,陶瓷与钎料发生化学反应,在陶瓷表面形成由TiO、TiC等物相组成的反应层。采用有限元法,对SiCw/Al2O3复合陶瓷/反应层界面的热应力进行了计算。结果表明,复合陶瓷/反应层界面的残余应力变化急剧,最大拉应力位于晶须、基体和反应层交界处;晶须内部及其表面存在较高的双向压应力,Al2O3基体主要承受垂直于界面的拉应力;SiC晶须/反应层界面及其附近的反应产物TiC内具有较高的平行于界面的拉应力,当连接界面承受剪力作用时,SiC晶须/反应层界面和TiC处极易破坏。借助TEM和SEM观察了复合陶瓷/反应层界面区的精细结构和剪切断口形貌,并利用计算结果对观察到的现象进行了分析。 相似文献
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《Science & Technology of Welding & Joining》2013,18(2):124-130
AbstractFriction welding was carried out between TiNi alloy and austenitic stainless steel with and without a Ni interlayer. When TiNi alloy was welded to stainless steel without the Ni interlayer, a large amount of brittle Fe2Ti intermetallic compound was formed at the weld interface. The formation of this brittle compound led to degradation of the joint strength. The Ni interlayer changed the microstructures at the weld interface and improved the joint strength. A fracture occurred at the interface between Ni and TiNi. The interface between Ni and TiNi was free from Fe2Ti and consisted of mainly TiNi3 and TiNi. After TiNi3 was formed as the reaction layer, a eutectic reaction occurred between the TiNi3 and TiNi base alloy. A reaction layer with a eutectic structure tends to form at the periphery, where the temperature would be higher than that of the central region. 相似文献
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《Science & Technology of Welding & Joining》2013,18(4):293-300
AbstractFibre laser–cold metal transfer hybrid welding was introduced to join AA 6061 aluminium alloy with AISI 304 stainless steel using Al–12Si filler wire. Interface properties and microstructure of welded joints were observed by optical microscope, scanning electron microscope, energy dispersive spectrometry and X-ray diffraction techniques. A serrated intermetallic compound (IMC) layer was found at the interface between fusion zone and stainless steel. The morphology of IMC layer was uniform from the top to the bottom, and its average thickness was 3 μm. The IMC layer consisted of two layers: Al8(Fe,Cr)2Si layer close to fusion zone and (Al,Si)13Fe4 layer close to stainless steel. The joint fractured at the IMC layer and presented a tensile strength of 165 MPa. The formation of the IMC layer was closely related with the thermodynamic and kinetic behaviours of the interface and fast cooling rate of hybrid welding. 相似文献