H62黄铜超薄板微搅拌摩擦焊接热机特征与接头组织性能研究  

Thermo-mechanical Characteristics and Microstructure and Properties of Micro-stir Friction Welding of H62 Brass Ultrathin Plate

作　　者：张昌青[1] 秦卓 荣琛 师文辰 王树文 王希靖[1] ZHANG Changqing;QIN Zhuo;RONG Chen;SHI Wenchen;WANG Shuwen;WANG Xijing(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal,Lanzhou University of Technology,Lanzhou 730050)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050

出　　处：《机械工程学报》2020年第12期65-72,共8页Journal of Mechanical Engineering

基　　金：兰州理工大学有色金属先进加工与回收国家重点实验室学校技术基金资助项目(02018006)。

摘　　要：铜及铜合金的微连接可在航空技术、电子技术及能源技术等方面广泛应用,但材料的软化温度高、薄板焊缝区塑性金属减少带来的摩擦产热减少、薄板比表面积增大带来的传热速度快等问题,使得微搅拌摩擦焊接(Micro friction stir welding,μFSW)工艺过程易产生焊接缺陷而不利于接头成形。以0.6mm厚的超薄板H62黄铜为研究对象,开展对接焊接试验研究,深入研究不同工艺参数下接头的微观组织、力学性能及断口形貌,进而优化工艺参数;在此基础上,分析该工艺过程中温度、轴向力和横向力的变化规律。研究表明:工艺优化后的焊缝成形良好,接头最大抗拉强度达370MPa,约母材(Basemetal,BM)的92.5%;焊缝处的热影响区(Heataffectedzone,HAZ)、热机影响区(Thermo-mechanically affected zone,TMAZ)、焊核区(Nugget zone,NZ)存在明显的分界线,且NZ在横向和纵向上晶粒形状和尺寸存在不均匀性,NZ硬度最高约为155.4HV(约BM的119.5%),断裂失效易发生在硬度最小的位置(Advancingsideoftheweld,AS),其失效机理为韧性断裂。在μFSW过程,稳定的轴向力和横向力可提供适当的热输入量以及更好的挤压和搅拌作用,从而得到性能良好的焊缝。通过对高熔点铜及其合金超薄板的搅拌摩擦焊的基础研究,从而为微连接技术的材料推广提供技术支撑。Micro-connections of copper and copper alloys can be widely used in aviation technology,electronic technology and energy technology,but the material has a high softening temperature,a reduction in frictional heat generation due to the reduction of plastic metal in the weld zone of the sheet,and an increase in the specific surface area of the sheet The problems such as the fast heat transfer speed make the micro friction stir welding(μFSW)process easy to produce welding defects and are not conducive to joint formation.Using 0.6 mm thick ultra-thin plate H62 brass as the research object,carry out butt welding experimental research,in-depth study of the microstructure,mechanical properties and fracture morphology of the joint under different process parameters,and then optimize the process parameters;on this basis,analyze Changes in temperature,axial force and Transverse force during the process.The research shows that the weld seam is well formed after the process optimization,and the maximum tensile strength of the joint reaches 370 MPa,about 92.5%of BM;there is a clear dividing line between HAZ,TMAZ,and NZ at the weld,and NZ is horizontal and vertical.There is non-uniformity in grain shape and size.The highest NZ hardness is about 155.4 HV(approximately 119.5%of BM).Fracture failure easily occurs at the location with the smallest hardness(AS).The failure mechanism is ductile fracture.In theμFSW process,stable axial and Transverse forces can provide appropriate heat input and better extrusion and agitation to obtain a good weld.Through basic research on friction stir welding of high-melting-point copper and its alloy ultra-thin plates,it provides technical support for the promotion of materials for micro-connection technology.

关 键 词：H62黄铜 微搅拌摩擦焊 过程分析 显微组织 抗拉强度 

分 类 号：TG456[金属学及工艺—焊接]