Al₂O₃弥散铜/T2铜真空扩散焊研究

【作者】 梁欢；

【导师】 陈健；

【作者基本信息】 江苏科技大学 ， 材料加工工程， 2011， 硕士

【摘要】 Al₂O₃弥散强化铜软化温度高达930℃,抗拉强度可达600MPa以上,电导率最高可达86.49%IACS,使用寿命为铬锆铜合金电极的4～10倍。以Al₂O₃弥散强化铜合金替代铬锆铜电极,与T2铜用扩散焊方法连接在一起制成复合构件,不仅能提高工效,而且能节约大量能源。本文采用真空扩散连接工艺,对Al₂O₃弥散强化铜/T2铜的连接进行了试验研究。用金相显微镜和扫描电镜分析了Al₂O₃弥散强化铜/T2铜扩散界面组织结构,研究了工艺参数对界面结合状态和组织结构的影响。观察接头界面组织可分为靠近T2铜侧的I区和焊缝中心区的II区以及靠近Al₂O₃弥散铜侧的III区。加热温度越高,Al₂O₃弥散铜/T2铜接头界面过渡区的宽度越大,界面过渡区组织越粗化。采用能谱分析界面结构成份组成以及元素分布情况,结果表明,接头界面I区为Cu（Ti）固溶体和少量Cu-Ti化合物,II区主要为Cu-Ti化合物,III区为Cu（Ti）固溶体和Cu-Ti化合物以及极少量Ti-Al化合物。界面区Al₂O₃弥散铜侧和T2铜侧Ti元素都有聚集。通过正交结果判断各因素对Al₂O₃弥散铜/T2铜固相扩散连接接头拉伸强度影响的主次关系为:扩散温度>压力>保温时间,即扩散温度是最重要的影响因素,其次是压力,影响最小的因素是保温时间。正交试验结果表明:最优的工艺参数方案是5号:焊接温度为550℃,保温时间为3h,压强为25MPa,观察在此参数下的Al₂O₃弥散铜/T2铜接头微观组织形貌,连接界面连续性非常好,基本不存在孔洞,接头冶金结合也最好,所得组织致密均匀。本文对Al₂O₃弥散强化铜/T2铜扩散连接界面结构、界面反应机理、界面断裂等进行了研究,该研究工作为Al₂O₃弥散强化铜/T2铜的推广应用提供了试验依据和理论基础,为Al₂O₃弥散强化铜/T2铜扩散连接提供了研究思路。更多还原

【Abstract】 Softening temperature of Al₂O₃ dispersion-strengthen copper is up to 930℃, it’s tensile strength is up to 600MPa and good conductivity of 86.49%IACS. The lifetime of Al₂O₃ dispersion-strengthen copper is 4 to 10 times more than CuCrZr alloy electrode. Using Al₂O₃ dispersion-strengthened copper alloy to replace the CrZrCu alloy electrode to make composite components with T2 copper, through diffusion welding process, can improve working efficiency and save alot of energy.In this paper, Al₂O₃ dispersion-strengthen copper/T2 copper was bonded together by vacuum diffusion bonding technology. The microstructure feature of the joint interface was investigated by optical microscope and scanning electron microscope. The influence of diffusion bonding parameters on interface combining state and microstructure of Al₂O₃ dispersion-strengthen copper/T2 copper interface was studied. The jiont consists of three parts: I area is near T2 copper; II area is in the seam center; III area is near Al₂O₃ dispersion-strengthen copper. With the increase of heating temperatuer the transition zone width of the Al₂O₃ dispersion-strengthen copper/T2 copper interface broadened and the The Grain Growth in transition zone. Ti aggregated at the edge of Al₂O₃ dispersion-strengthen copper and T2 copper in the brazing process, and it’s much more obvious at the Al₂O₃ dispersion-strengthen copper side.The most influential factor on the adhensive strength of the joint was difussion temparature,followed by pressure and holding time, analysised by orthorhombic-experiment method.and the means of orthogonal result show that the optimized paramenters for the joint were gained as fellows: diffusion temperature was 550℃, holding time was 3 h, pulse pressure was25MPa. The jointstrength under the optimum condition was 166.9MPa. The microstructure feature of the Al₂O₃ dispersion-strengthen copper/T2 copper joint interface was investigated by optical microscope and scanning electron microscope in the optimized paramenters and the joint interface bounding well.There is no Confucianism and crack.Compositions in I district of the joint interface were the Cu（Ti）solid solution and a small amount of Cu-Ti compounds, Cu-Ti compounds in II district mainly, Cu（Ti）solid solution, Cu-Ti compounds and a very small amount of Ti-O compounds in III district The microstructuer, interface formation mechanism and interface fracture of Al₂O₃ dispersion-strengthen copper/T2 copper diffusion bonding joint were sdudied in the paper. The studies can provide experiental basis and theoryfoundation for the wide application of Al₂O₃ dispersion-strengthen copper/T2 copper.更多还原