摘要
三维金属波导元件(包含接收信号孔、本振信号孔和耦合孔)是下一代射电望远镜的关键器件。超声增材为制备该波导元件提供了一种全新的方法,而紫铜薄片的有效焊接是该方法中最关键的工艺之一。当前对紫铜超声波的研究主要集中在焊接参数优化上,鲜有关于紫铜超声波焊接再结晶的研究。本工作采用电子背散射衍射(EBSD)技术观察紫铜超声波点焊的微观组织结构以及织构变化,研究紫铜超声波点焊的再结晶过程。结果表明:超声波焊接作用下紫铜焊接界面处的平均尺寸从20μm减小到1~2μm,说明超声波焊接细化了界面处晶粒;原始紫铜基体内主要包含具有大角度晶界(HAGBs)的粗大晶粒,而紫铜焊接接头界面处则出现了大量的小角度晶界(LAGBs)、亚晶和细小的等轴晶粒;原始紫铜中主要存在着铜型织构{112}〈111〉以及立方织构{001}〈100〉,而超声焊接后试样的织构主要有剪切织构{111}〈143〉、{111}〈110〉与{221}〈122〉,其中在焊接界面处存在大量重新生成的细小立方织构{100}〈001〉和剪切织构{111}〈110〉;在应变较小区域,通常发生不连续动态再结晶DDRX,此时再结晶形核方式为晶界弓出形核方式,而在应变较大区域则以连续动态再结晶CDRX为主,再结晶形核方式与亚晶相关。
Three-dimensional metal waveguide element which includes received signal holes,local vibration signal holes and coupling holes is the key device of the next generation radio telescope.Ultrasonic augmentation provides a new method for fabricating the waveguide element,and the effective welding of copper sheet is one of the most important processes in this method.Previous studies on ultrasonic welding of red copper mainly focused on the optimal welding process,and few researches on recrystallization of copper ultrasonic welding were carried out.In this paper,Electron Backscattered Diffraction(EBSD)technique was used to observe the microstructure and texture changes of ultrasonic spot welding of copper,and the recrystallization process of ultrasonic spot welding of copper was studied.The results show:The average size at the interface of copper is reduced from 20μm to 1-2μm under the action of ultrasonic welding,which indicates that the grain size at the interface is refined by ultrasonic welding.There are mainly copper texture{112}〈111〉and cubic texture cube{001}〈100〉in the original red copper.After ultra-sonic welding,there are mainly shear textures{111}〈143〉,{111}〈110〉and{221}〈122〉,in which a large number of regenerated fine cuboidal textures{100}〈001〉and shear textures{111}〈110〉exist at the welding interface.In the region with the small strain,discontinuous dynamic recrystallization DDRX usually occurs.The recrystallization nucleation mode is the grain boundary nucleation mode,while in the larger strain region,the continuous dynamic recrystallization CDRX is dominant.The crystalline nucleation form is related to the subgrain.
作者
肖乾坤
朱政强
李铭锋
XIAO Qiankun;ZHU Zhengqiang;LI Mingfeng(College of Mechanical and Electrical Engineering,Nanchang University,Nanchang 330031,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2020年第10期10157-10161,共5页
Materials Reports
基金
国家自然科学基金(51365039)
国家自然科学基金委员会-中国科学院天文联合基金(U1731118)。
关键词
紫铜
超声波焊接
EBSD
再结晶
织构
copper
ultrasonic welding
electron backscattered diffraction(EBSD)
recrystallization
texture
