基于转移脉冲火花放电通道的金属悬垂结构无支撑熔丝增材成形研究

Research on the Machining of Unsupported Fused Wire Additive for Metal Suspension Structures Based on Transfer Pulse Spark Discharge Channel

针对电弧熔丝增材制造过程中高水平热输入带来的成形过程不稳定、微观组织不精细以及拉伸强度较低等问题,提出了一种以脉冲火花放电通道为热源的新型金属增材制造方法,此法火花放电通道形成在エ具电极与金属丝材之间,之后膨胀并转移至工具电极和成形件之间,有效降低了成形过程中的热输入。通过将该法应用于悬垂结构的无支撑成形,以倾斜角为45°的单元杆为研究对象,研究了放电电流、脉冲宽度、脉冲间隔、送丝速度和扫描速度对成形精度和形貌的影响,进而成功实现了倾斜角为0°~90°细长杆及体心立方点阵结构的无支撑增材制造。

To address the problems of the unstable forming process,coarse microstructures and low tensile strength caused by high-level heat input in wire arc additive manufacturing,a new metal additive manufacturing method that uses a pulse spark discharge channel as a heat source was proposed.In this method when a pulse voltage is formed,the arc plasma is initially ignited between the tungsten electrode and the filler wire and then gradually transferred to the gap between the tungsten electrode and the deposited layer,which effectively reduces the heat input during the forming process.By applying this method to the unsupported forming of suspended metal structures,the effects of discharge current,pulse width,pulse interval,wire feeding speed and scanning speed on the forming accuracy and morphology of unit rods with a tilt angle of 45°were studied.Subsequently,the unsupported metal additive manufacturing of slender rods with angles of 0°~90°and body-centered cubic lattice structures was successfully achieved.