基于脉冲等离子焊接快速成形工艺研究

摘要

The technology of rapid prototyping based on pulsed plasma arc welding （PAW） is used for impro- ving the accuracy of the deposited part, and a system of rapid prototyping based on welding robot is developed. The influences of PAW parameters such as peak current, duty cycle, welding speed and wire feed rate on the ratio of width to height of the deposited track cross-section are investigated. Two models including overlapping model between deposited tracks and an ideal model for calculating interlaminar height are established. The effect of the ratio of width to height on the accuracy and quantity of formed parts is investigated. The results show that the large ratio of width to height can improve accuracy and quality of rapid prototyping parts, and a- void the generation of the voids. The appropriate interlaminar height and heat input can enhance the shaping accuracy of thin wall part.%为了提高快速成形零件的成形精度,采用脉冲等离子焊接快速成形方法,利用所建立的机器人快速成形系统,研究了峰值电流、焊接速度、占空比、送丝速度等工艺参数对成形轨迹宽高比的影响规律,并建立了快速成形轨迹间搭接模型以及层间高度的计算模型,分析了单道成形轨迹的宽高比对多道搭接表面平整度的影响规律.结果表明,选择宽高比较大的成形轨迹进行快速成形,有利于提高成形件的表面平整度,降低孔洞等缺陷的产生.合适的层间高度参数以及热输入量的控制能够有效地提高薄壁结构件的成形精度.