铜铝接头锻接扩散焊.pdf

摘 要 I论文题目：铜铝接头锻接扩散焊 论文题目：铜铝接头锻接扩散焊 专 业：材料加工工程 专 业：材料加工工程 研 究 生：洪丽玲 研 究 生：洪丽玲 指导教师：辛选荣 副教授 指导教师：辛选荣 副教授 摘 要 摘 要 铜与铝在人们日常生活中有着极为广泛的应用，在工业生产中有着极为重要的地位，铜与铝在高压电器中的配合应用不仅是必然的也是经济的，铜与铝的焊接在异种金属焊接中具有相当重要的地位本文借鉴真空扩散焊工艺原理，提出了一种新型的焊接工艺—锻接扩散焊该工艺克服了真空扩散焊焊接周期长，成本高，技术含量高，对普通工业和民用产品不合算的缺点。

通过试验验证了锻接扩散焊的可行性，对于提高实际生产率和开辟焊接领域新工艺具有重大应用价值和理论意义 本文试验用材料为 T2 铜与 2A50 铝合金，直径为 Φ34mm试验时，先对工件进行表面处理，包括打磨和酸洗，然后将工件放在夹具上进行冷压，将压合后的工件随同夹具一起放入 520～530℃的普通箱式电阻炉中保温 90min，然后取出热压一次，再次放入箱式电阻炉中扩散 90min，最后取出空冷利用扫描电镜(SEM)、能谱分析(EDS)、显微硬度、X 射线衍射(XRD)、拉伸性能测试、导电性能测试等测试方法对试验获得的铜/铝接头进行研究试验结果表明，在锻接扩散焊接头界面存在明显的扩散区，扩散区宽度大约为 2mm，焊缝由铜侧结合面，中间焊缝，铝侧结合面三部分组成在铜基体与焊缝之间出现了光亮带，形成了致密的新相化合物层接头导电性能良好，符合实际生产要求，接头强度满足使用要求 对比中的真空扩散焊必须在真空炉中进行，受炉膛及其压力的限制，只能焊接较小截面的工件，一次加热抽真空仅能焊一个工件而本文这一锻接扩散焊过程没有严格的设备要求，焊件尺寸不受炉膛及其压力的限制，焊接压力仅为冷压焊的十几分之一，可焊接尺寸较大，形状复杂的工件，焊接成本较低，焊接质量良好。

由上述过程可知锻接扩散焊接可分为三个阶段：第一阶段冷压预制；第二阶段加热锻焊；第三阶段体积扩散，微孔和界面消失首先通过第一阶段的冷压使待焊表面微观凸起部位发生塑性变形，氧化膜破碎；使表面微观凹陷部位空气排出，两表面接触，形成无杂质表面其次通过第二阶段在加热的过程中通过夹具摘要 II给工件施加压力，使接触面积不断增大，使空气不再进入然后热压使待焊表面晶粒破碎、孔洞消除、新生表面形成、扩散加速最后的第三阶段为体积扩散，微孔和界面消失事实上第一阶段仅仅是预制，这一阶段并未产生冶金结合；第二阶段建成了牢固的冶金结合，但这时的接头组织和成分与母材相差较大，接头强度并不高，必须继续保温扩散一段时间，以完成第三阶段，使扩散层达到一定深度，获得高质量的接头 关 键 词：关 键 词：铜，铝合金，锻接扩散焊，夹具，显微组织 论文类型：论文类型：应用基础研究 摘要 IIISubject: Blacksmith Diffusion Welding of Cu/Al Joint Specialty: Material Processing Engineering Name: Hong Li-Ling Supervisor: Xin Xuan-Rong Associate Professor ABSTRACT The copper and the aluminum have extremely widespread application in people’s daily life, has the great important position in the industry production, copper and aluminum coordinate application in high-handed wiring is not only inevitable is also the economy, the welding technology of them plays an important role in heterogeneity welding. This article will offer a new welding technology-blacksmith diffusion welding which referenced vacuum diffusion welding principle. It can get over the disadvantage brought by vacuum diffusion welding like long period, high cost, high-tech contents and not economical for common industry using. The feasibility of the new procedure is proved by experiment, and it has important application value a great theoretical significance. T2 copper and A250 aluminum alloy are used in the experiment. The diameter is Φ34mm. Surface disposal including polish and acid wash is done at first. Then, the work piece need to be cold pressed on the clamp, and put in normal box resistance furnace with the clamp for heat preservation for 90min, the temperature is 520～530℃. Next, it is heat pressed then diffused in the furnace for 90min.air cooling is the last process. The microstructure was researched by means of various test methods, such as SEM, EDS, micro-hardness test, XRD, tensile test, electric-conductivity measure and so on. The result make it clear that diffusion section exist on the blacksmith diffusion welding joint surface, the wide is about 2mm. Weld is constituted with copper side diffused section, middle weld line and aluminum side section. A bright belt is found between copper part and welding line. This is the compact new compound bed. The welding has a good electric capability and strength satisfy the use requirement. In the contrast vacuum diffusion welding must carry on the vacuum furnace, the hearth and the pressure limit, can only welding the small cross section the work piece, a heating pulls out the vacuum only to be able to welding a work piece. But this article this blacksmith diffusion welding the process not strict equipment request, the weldment size the hearth and the pressure limit, the welding pressure is only not the 摘要 IVcold pressure welding several 1, may weld the size to be big, the shape complex work piece, the welding cost is low, the welding quality is good Blacksmith diffusion welding can divide into three stages by the above process: First stage cold-press prefabrication; second stage heating blacksmith welding; Third stage volume diffusion, microporous and interface disappeared. First causes through the first stage’s cold-press the superficial to be welded microscopic bulge spot to have the plastic deformation, the oxide film is broken up. Causes the superficial microscopic hollow spot air to discharge, two surface contacts, form the non-impurity surface. Next brings the pressure through the second stage in the heating process through the fixture to the work piece, causes the contacted area to increase unceasingly, make the air no longer to enter. Then the hot-pressing causes the superficial to be welded crystal grain to be broken, the hole eliminates, the neonatal surface to form, the welding acceleration. The final third stage is the vo。