异种合金材料的超声焊接工艺及其机理研究

发布时间：2018-11-07 19:04

【摘要】：超声金属焊接的工作原理是在工件上施加压力以及高频剪切运动来实现材料间的固态连接,是一种高效、便捷的焊接加工技术。虽然超声金属焊接技术被广泛应用于工业领域,但目前对焊接接头的结合机理研究还存在不足。为了更好的运用这项技术,本文针对异种合金材料(锂电池金属极片0.1mm厚度的铝/镀镍钢片)进行超声焊接,对其结合强度和连接机理进行深入的研究。试验中,本文首先通过CETR型样品测试系统获得接头的剥离强度值,分别采用单因素变量法和正交试验法分析不同焊接工艺对接头强度的影响程度。随后,采用数字显微硬度计测量接头硬度值,获得不同焊接工艺对焊缝组织细化程度的变化规律;进一步采用分阶振幅与恒定振幅进行焊接试验,分析不同焊接模式对接头结合强度和表面形貌的影响作用。最后,利用3D激光扫描显微镜对焊缝组织进行观察并总结分析超声焊接接头的结合机理。结果表明,通过单因素分析得到三种焊接工艺参数(焊接时间、焊接振幅和焊接压强)对接头强度都有一定程度的影响,而正交分析得到焊接振幅对接头强度的影响最大。硬度测量得到焊接振幅对接头硬度的影响程度大于焊接时间,说明焊接振幅可提高金属晶粒的细化程度。采用分阶振幅可获得更高强度的焊接接头且其标准差小,减少了接头表面与工具头的粘附现象,剥离试验前的焊件表面相对平整,有效防止了较软金属产生裂痕。对焊缝微观组织形貌进行观察得到,超声焊接可破碎金属表面氧化膜且结合区未发现有严重的熔化现象,但其界面处的金属键合作用和物理冶金反应对接头的形成过程起了关键作用,是实现固相连接的基础。
[Abstract]:The working principle of ultrasonic metal welding is to apply the pressure on the workpiece and the high frequency shear motion to realize the solid state connection between the materials. It is an efficient and convenient welding technology. Although ultrasonic metal welding technology is widely used in industry, the research on bonding mechanism of welded joints is still insufficient. In order to make better use of this technology, ultrasonic welding of different alloy materials (aluminum / nickel plated steel sheet with 0.1mm thickness of metal electrode sheet of lithium battery) is carried out, and the bonding strength and bonding mechanism are studied deeply. In the experiment, the peeling strength of the joint was obtained by CETR sample testing system, and the influence of different welding processes on the joint strength was analyzed by single factor variable method and orthogonal test method respectively. Then, the hardness value of the joint was measured by digital microhardness meter, and the variation law of weld microstructure refinement was obtained by different welding processes. The effects of different welding modes on the bonding strength and surface morphology of the joints were analyzed by means of step amplitude and constant amplitude welding tests. Finally, the weld microstructure was observed by 3D laser scanning microscope and the bonding mechanism of ultrasonic welded joints was summarized and analyzed. The results show that three kinds of welding parameters (welding time, welding amplitude and welding pressure) have some influence on the joint strength by single factor analysis, while the orthogonal analysis shows that the welding amplitude has the greatest influence on the joint strength. The influence of welding amplitude on joint hardness is greater than that of welding time, which indicates that welding amplitude can improve the refinement of metal grain. A higher strength welded joint can be obtained by using the step amplitude, and its standard deviation is small, which reduces the adhesion between the joint surface and the tool head, and the surface of the welding piece is relatively flat before peeling test, which effectively prevents the crack of the soft metal. By observing the microstructure of the weld, it can be found that the oxide film on the surface of the metal can be broken by ultrasonic welding and there is no serious melting phenomenon in the bonding zone. However, the metal bond cooperation at the interface and the physical metallurgical reaction play a key role in the formation of the joint, which is the basis for the solid phase bonding.
【学位授予单位】：集美大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG453.9

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