NdFeB永磁体与SPCC钢激光点焊的显微组织特征研究  

Microstructural characteristics of laser spot welds of NdFeB permanent magnet and SPCC steel

作　　者：伊晨晖[1] 常保华[1] 都东[1] 张骅[1] 李艺红 

机构地区：[1]清华大学机械工程系先进成形制造教育部重点实验室,北京市100084 [2]太原市拓力拓科技有限公司,030032

出　　处：《焊接》2014年第4期27-30,74,共4页Welding & Joining

摘　　要：利用连续光纤激光器对烧结NdFeB永磁体与SPCC钢实施了激光搭接点焊,分析了接头的显微组织特征。结果表明:熔核内部存在结晶裂纹和多种不同类型的气孔缺陷,NdFeB内部的熔核周围存在液化裂纹;熔核中的凝固组织主要为α-Fe和富Nd相;α-Fe主要为柱状树枝晶,局部位向相近的柱状树枝晶形成柱状晶区,不同柱状晶区的位向存在明显差别;富Nd相主要分布在熔核上表面的外围,少量分布在熔核内部、熔核缩颈处的外围及部分气孔内壁。对形成上述显微组织的机理进行了初步分析。Laser lap spot welding of sintered NdFeB permanent magnets and SPCC steels was carried out by using continuous fiber laser.The microstructures of the welds show that solidification cracks and different types of porosities exist in the internal of the nuggets,and liquation cracks exist in the HAZ of NdFeB part.The microstructures of the welds are mainly composed of α-Fe and Nd-rich phase.Most of the α-Fe phases are columnar dendrites;columnar dendrites with similar orientation in local region form columnar zones,and the orientations of different columnar zones are quite different from each other.The Nd-rich phase are mainly distributed at the periphery of the top surface of nuggets,and a small amount of Nd-rich phase are distributed within the nuggets,at periphery of the necking zone of nuggets,or on the inner wall of some porosities.The reasons that lead to such microstructures are analyzed briefly.

关 键 词：激光点焊 烧结NDFEB永磁体 显微组织 

分 类 号：TG456.7[金属学及工艺—焊接]