摘要
采用交流钨极氩弧焊(AC-TIG)方法成形多层单道5356铝合金薄壁件,研究电流方式对堆焊结构显微组织及力学性能的影响。结果表明:无脉冲电流方式成形件结合层组织呈枝晶状,基体存在大量尺寸为50~100μm的气孔和缩孔等缺陷,沉积层由尺寸为100~150μm的粗大等轴晶组成;脉冲电流试样结合层由具有明显择优取向的细小枝晶组成,气孔尺寸减小,沉积层由尺寸为50~100μm的等轴晶组成;两种电流成形试样硬度值变化规律相似,即沉积层硬度值稳定而结合层波动剧烈,脉冲电流成形试样强塑性均高于无脉冲电流,两种试样在拉应力作用下均沿切向以韧性断裂为主,断口呈典型等轴韧窝状。结果表明:采用低频交流脉冲调质堆焊工艺,可获得最佳堆焊结构件,为实际工程应用提供理论依据及技术支撑。
The multi-layer single-pass 5356 aluminum alloy thin-wall parts were formed by alternating current tungsten inert gaswelding(AC-TIG).Effect of current mode on the microstructure and mechanical properties of the formed parts during thesurfacing process was studied.The results show that under the no-pulse current mode,dendrites and lots of defects such as poresand shrinkage holes of 50-100μm appear in the combined layer,and larger equiaxed grains of 100-150μm are formed in thedeposited layer.Under the pulse current mode,fine dendrites with obvious preferential orientation and the smaller size of poresappear in the combined layer,and smaller equiaxed grains of 50-100μm are formed in the deposited layer.The hardness of thesamples formed by two kinds of current mode is similar,that is,the hardness value of the deposited layer is stable while that ofthe combined layer fluctuates violently.The strength and plasticity of pulse current specimen are higher than those of no-pulsecurrent specimen.Both tensile specimens are mainly ductile fracture along tangential direction,and the fracture is typical equal-axial dimple.The results show that the optimum welding structure can be obtained by adopting low-frequency AC pulse weldingprocess parameters,which will also provide theoretical basis and technical support for practical engineering application.
作者
赵鹏康
蒲尊严
杨笑宇
李言
李淑娟
ZHAO Pengkang;PU Zunyan;YANG Xiaoyu;LI Yan;LI Shujuan(Shaanxi Provincial Key Laboratory of Machinery Manufacturing Equipment,Xi′an University of Technology,Xi′an 710048,China;Key laboratory of the Ministry of Education for Integration of CNC Machine Tools and Machinery Manufacturing Equipment,Xi′an University of Technology,Xi′an 710048,China)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2020年第2期47-51,共5页
Ordnance Material Science and Engineering
基金
中国博士后面上基金(2017M613172)
陕西省教育厅自然科学基金(17JK0562)
校博士启动基金(102-451116012).
关键词
电弧增材
电流方式
5356铝合金
组织性能
additive manufacturing with arc
current mode
5356 aluminum alloy
microstructure and properties
