Research On The Influence Of GTAW Process Parameters On Titanium Alloy Additive Manufacturing Forming

Gas tungsten arc welding(GTAW)additive manufacturing,using high temperature arc as the heat source,melting a filler wire,layer by layer deposition to form metal parts.The GTAW high efficiency,low cost,no splash,forming good effect.This paper focus on TC4 titanium alloy,analyzing the influence of the forming parameters on the droplet transfer in GTAW additive manufacturing.Designing the test and surface-shaped,in order to improve forming,while testing the mechanical properties of molded parts and compared with the casting and forging,in order to achieve and exceed the casting and forging.At present,domestic research on this aspect is still in the preliminary stage.Through the establishment of the mathematical relationship between process parameters and the droplet transfer,and then analyze the impact of the process parameters on the droplet transfer.Meanwhile,the influence of process parameters on droplet transfer mode and droplet quality and the influence of swing parameters on droplet transfer were analyzed.The droplet transfer process was numerically simulated by the software of fluent and the method of VOF in order to obtain the influence of process parameters on droplet transfer mode and analyze the influence of gas flow rate on droplet transfer process.It is noted that the wire feed speed is a parameter for changing the droplet transfer mode.The gas flow rate can accelerate the droplet transfer and affect the droplet shape.In order to obtain a fine droplet transfer process to provide a process parameter adjustment trend.According to the needs of the titanium alloy forming environment,we are designing the experiment machines and fixture for ourselves,and setting up the additive manufacturing forming system.Founded on the analysis of the influence of process parameters on the droplet transfer process,the influence of process parameters on the forming process was investigated by means of response surface design and orthogonal test design within the appropriate process parameters.The effects of the parameters on the forming width and the residual height are obtained.The influence of the parameters on the forming process is analysed by means of variance analysis,range analysis and trend chart.It is noted that the peak current is the main factor affecting the fusion width in the GTAW parameter,and the square of the peak current is the main factor that affects the residual height.In the speed and swing parameters,it was found that the wire feeding speed had the most significant effect on the residual height,while the deposition rate had the most significant influence on the weld width.At the same time,the multivariate nonlinear regression equation of the process parameters is obtained.A sound straight wall forming part was obtained by using the process parameters.By analyzing the mechanical properties of a series of shaped parts,the influence of process parameters on the mechanical properties was analyzed and compared with the mechanical properties of the cast and forged parts,which provided a basis for the forming of titanium alloy with good mechanical properties for the future.