Arc-Ing Wire VPPA Welding Technolegy And Research

As an important method of thermoforming,welding has become more and more widely used in manufacturing processes in all walks of life.Therefore,how to improve welding production efficiency and welding quality and reduce energy consumption has become a research hotspot in the welding session.Hybrid welding plays an increasingly important role in controlling the welding process with its unique energy action characteristics.It shows unique advantages in its respective fields: control of heat input,increase of welding efficiency,and increase of penetration depth.The arcing wire VPPA welding technology used in the present study,compared with the traditional VPPA welding method,incorporated a variable polarity plasma arc controlled by the power source between the tungsten electrode and the bypass wire,which stabilized the droplet transition,increased the fuse efficiency,and improved the welding speed.In this hybrid welding method,the polarity of MIG and VPPA arc can be controlled independently,so that the welding parameters can be controlled in a wider range,and the thermal and mass decoupling in the welding process can be realized.As a new welding process method,the arc hot wire-VPPA welding technology is still in a blank state.Therefore,the present study has focused on research in heat transfer,mass transfer,welding heat input and fuse efficiency,and additive manufacturing.Firstly,based on the concept of heat and mass decoupling control of the welding process,the mutual matching coupling between two variable polarity arcs is the research content,and a set of coupling and matching control system board of variable polarity pulsed MIG and variable polarity plasma arc was designed.The control system board realizes the stable cooperation between the two arc waveforms and achieves a smooth arc start,achieving a good transition state of the droplets;and then under the concept of heat transfer and mass transfer decoupling,the welding arcs under two conditions were studied.The effects of the welding arcs under two conditions on the weld morphology(melting width,penetration depth,and residual height)were studied.It was found that the effect of the heat transfer process on the weld width and depth of penetration was much greater than that of the mass transfer process.On the contrary,the influence of the mass transfer process on the residual height is much greater than the effect of the heat transfer process on the residual height of the weld.Secondly,from the aspect of energy consumption and welding wire melting efficiency,the polar MIG and variable polarity plasmas that constitute the VPPA welding process of the electric arc heating wire and the energy consumption were analyzed under the same process with the same amount of fuses and similar weld morphology.It was found that the addition of the coupling arc can accelerate the melting of the welding wire and improve the quality of the weld.At the same time,this composite welding process meets the characteristics of low energy consumption,good shaping,and excellent overall energy efficiency ratio;The study on the melting efficiency of the welding wire in this welding process found that the composite arc can accelerate the melting of the welding wire and improve the efficiency of the fuse.Moreover,the MIG arc fuse function is higher than that of the plasma arc,and at the same tiem the best parameter range of energy matching was found.Finally,based on the controllable heat and mass input characteristics of this process,an additive-formed single-wall test was conducted,and the additive-molded sample was modeled using a quadratic universal rotation combination method,and the molding size was predicted,it was found that the model has higher prediction accuracy.The process parameters affecting the width and height of the sample were analyzed.It was found that the plasma current,wire feed speed,and welding speed had a major effect on the layer height,and there was an interaction between the plasma current and the welding speed on the layer height.The plasma current,variable polarity MIG current,and welding speed played a major role in the melt width.The accuracy of the model prediction was verified.The results showed that the model predicting the accuracy of the molding dimension is high,and the established model is effective and reliable.The additive width and width stability control scheme for additive material was designed,and the minimum variance value was obtained by adjusting the difference in the difference,so that the melting width of the additive sample was approximately the same,which was the best control scheme.