To develop low-cost additive manufacturing for metal parts, a methodology, namely, pneumatic extruding direct-writing deposition (PEDWD), is investigated in this paper. The deposition system mainly consists of a pressure and valve controller, temperature controller, three degree-of-freedom motion platform and computer system. By adopting the pressure of compressed nitrogen, molten metal was extruded on demand and deposited onto a substrate to form metal parts along the programmed track. A throttle channel was introduced into the structure design of the nozzle, and the effect of the throttle channel on the flow of the molten metal was investigated theoretically and experimentally. A Comparison of the theoretical analysis results and the experimental results shows good agreement. The experimental measurement results suggest that the throttle channel decreases the flow of molten metal by approximately 28%. How the two key processing parameters, the velocity of the substrate and the distance between the substrate and the nozzle, affect the deposition processing of PEDWD was investigated. Based on the experimental results, when the two parameters vary in a certain range, they both affect the outflow of the molten metal and the cross-sectional size and shape of the deposited metal line. Finally, thin-walled and three-dimensional metal parts were fabricated successfully by PEDWD, and their morphological characteristics were investigated.

为了开发金属零件的低成本增材制造，本文研究了一种方法，即气动挤压直写沉积（PEDWD）。沉积系统主要由压力和阀门控制器、温度控制器、三自由度运动平台和计算机系统组成。通过采用压缩氮气的压力，熔融金属被按需挤出并沉积在基板上，沿着程序轨迹形成金属零件。在喷嘴结构设计中引入节流通道，从理论上和实验上研究了节流通道对金属液流动的影响。理论分析结果与实验结果的比较显示出良好的一致性。实验测量结果表明节流通道使熔融金属的流量减少了大约 28%。研究了基板速度和基板与喷嘴之间的距离这两个关键工艺参数如何影响 PEDWD 的沉积工艺。根据实验结果，当这两个参数在一定范围内变化时，它们都会影响金属液的流出量和熔敷金属线的横截面尺寸和形状。最后，通过PEDWD成功地制备了薄壁和三维金属零件，并对其形态特征进行了研究。对 PEDWD 沉积过程的影响进行了研究。根据实验结果，当这两个参数在一定范围内变化时，它们都会影响金属液的流出量和熔敷金属线的横截面尺寸和形状。最后，通过PEDWD成功地制备了薄壁和三维金属零件，并对其形态特征进行了研究。对 PEDWD 沉积过程的影响进行了研究。根据实验结果，当这两个参数在一定范围内变化时，它们都会影响金属液的流出量和熔敷金属线的横截面尺寸和形状。最后，通过PEDWD成功地制备了薄壁和三维金属零件，并对其形态特征进行了研究。