急冷NiSi合金箔快速凝固连接接头组织分析  

Analysis of joint microstructure of melt-spun Ni-Si alloy foils by rapid solidification joining process

作　　者：翟秋亚[1] 张兴[1] 徐锦锋[1] 

机构地区：[1]西安理工大学材料科学与工程学院,西安710048

出　　处：《焊接学报》2007年第9期99-102,共4页Transactions of The China Welding Institution

基　　金：陕西省自然科学基金资助项目(2006E120);陕西省教育厅科学研究计划(06JK220)资助项目

摘　　要：应用微型电容储能焊机对厚度约35～45肿的急冷Ni-8．24％Si合金箔带进行了点焊连接，观察了接头组织，计算了熔核冷却速率，分析了点焊接头组织特征及其形成机理。结果表明，应用电容储能、瞬间放电所产生的高能量可以实现急冷合金箔带的连接，获得了直径102μm、高度48肿、形状比较规则的扁球状熔核。焊接时间短，接头冷却速率大，达到7．82×10^6K／s。熔核组织具有明显的快速凝固特征，由均匀细小的等轴晶组成，晶粒直径约0．5—3．0μm；熔合区宽度极小，仅2～3μm；与熔合区毗邻的箔带无组织粗化迹象。点焊接头组织与急冷箔带组织具有良好的匹配性。The spot welding characteristics of melt-spun Ni8.24%Si alloy foils with 35-45 μm in thickness were investigated using a mini-type capacitor discharge welding machine.The cooling rate of the nugget was calculated.The joint microstructure and its forming mechanism were also analyzed.The results indicate that the compact energy and instant discharge from capacitance can realize spot welding of rapidly solidified Ni-8.24%Si alloy foils,and a regular oblate spheroid nugget with 102 μm in diameter and 48 μm in thickness is formed.Owing to the momentary welding time hold in welding process,the cooling rate of the joint reaches to 7.82×106 K/s.Thus the microstructure of nugget is characterized by rapid solidification,which consists of fine and homogeneous equiaxed grains with the sizes of 0.5-3.0 μm.The bonding zone is rather narrow and its width is only 2.0-3.0 μm.Even more,there is not microstructural coarsening in base alloy near the nugget.Therefore,the microstructure of welded joint is extraordinary consistent with the microstructure of base alloy.

关 键 词：急冷合金箔 储能焊 组织形态 微型熔核 

分 类 号：TG115.28[金属学及工艺—物理冶金]