电弧热丝变极性等离子弧增材制造成型尺寸预测

电弧热丝变极性等离子弧(arcing-VPPA)对传热与传质的可靠控制使其在电弧增材制造方面拥有独特的优点。针对单道多层铝合金堆砌试样,利用二次通用旋转组合方法针对性地设计了单壁墙试验样本,通过多次回归方程建立了单壁墙成型尺寸与工艺参数之间关系的数学模型。结果表明,模型能够较好地预测单壁墙的熔敷尺寸,真实值与拟合值基本一致。同时发现,等离子电流、行走速度、送丝速度对层高的影响较为明显,且等离子电流与焊接速度对层高的影响存在交互作用;而对熔宽影响较明显的是等离子电流、变极性脉冲MIG电流以及焊接速度。同时分析了增材成型熔宽尺寸稳定性控制策略,发现等离子电流以等差数列排序的控制方案在增材宽度的稳定性控制上具有明显优势。

Forming size Prediction of additive manufacturing by Arc- heated wire VPPA welding

The ability of arcing wire VPPA to reliable control heat and mass transfer let it have unique advantages in arc additive manufacturing. In this paper, single channel multi-layered aluminum alloy specimens were assembled based on the quadratic general rotary unitized design method, and the mathematical model of single side wall forming dimensions and process parameters was established by multiple regression equations. This model can accurately predict the cladding size of single channel multi-layered aluminum alloy specimen. It was found that the plasma current, travelling speed, and wire feeding speed have significant effect on the layer height, and there is an interaction between the plasma current and travelling speed. For the melting width, the plasma current, variable polarity pulse MIG current and travelling speed have main effect. The width stability control strategy of this process was discussed based on the above results. It is found that the control scheme of the plasma current in the arithmetic progression has obvious advantages in the width stability control.