Investigation On Deposition Anisotropy And Path Planning Of Wire And Arc Additive Manufacturing

Wire and arc additive manufacturing(WAAM)attracts more and more attention because of its advantages of high deposition efficiency and low cost when depositing large and complex metal parts.However,wire and arc additive manufacturing has some disadvantages such as low deposition precision,lack of path planning suiting for WAAM and corresponding slicing software,which seriously limits its application.So this paper chose WAAM based on TIG as the research object and chose TC4 titanium alloy as deposition material.Firstly,the basic process and path planning were studied.And then the development of corresponding slicing software was finished.Finally,the component was deposited using developed slicing software.The research of this paper is of great significance to promote the development and application of WAAM.The research work mainly includes the following aspects:(1)Research on the basic deposition process.Firstly,the effect of process para meters on geometrical morphology of single weld pass was researched by control variate method.The range of process parameters of single weld pass stable deposited was obtained by trial-and-error method.Based on this,the influence of different orientatio n relationship between the wire feeding direction and depositing direction on the geometrical morphology was studied.To solve depositing anisotropy problem,this paper creatively proposed the method of rotating welding torch and wire feeding screw.And then,the effect of rotation angle of welding torch on depositing anisotropy was studied and the best rotation angle was obtained.The geometrical morphology,tensile mechanical properties,macroscopic grain structure and microstructure of the deposited components under the best rotation angle were all isotropic.(2)Research on the effect of path planning on geometrical morphology and properties.Firstly,the characteristics of WAAM,such as unstable height of position of arcing and arc-extinguishing,edge effect and side collapse,were introduced and the reasons of these problems were analyzed.For the cross position of typical frame structure,the path of arc overlap was put forward and finally “?” section frame structure with good surface was obtained.For the planar structure,five path planning methods were proposed,which were long-edge depositing,short-edge depositing,contour spiral depositing,partition depositing and interlayer long-edge and long-edge alternate permutation.The effect of path planning methods on the dimensional accuracy,residual stress,mechanical properties and microstructure were studied.The experimental results showed that the part deposited by short-edge was best.(3)Research on slicing software implementation.Firstly,the design requirements of slicing software which matches with process demand and equipment of WAAM were introduced.And then,the function of each sub-module of developed slicing software was introduced.The slicing algorithm of thin-walled rotary part matching process requirements of WAAM was put forward with the MATLAB programming and the thin–walled hemisphere part was deposited.Finally,a part was deposited by the developed software and the reason of low dimensional accuracy of deposited part was analyzed.The current software defects in the path planning module were pointed out.