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Research On Process Of Low Alloy Steel Structures By Wire And Arc Additive Manufacturing

Posted on:2020-05-19Degree:MasterType:Thesis
Country:ChinaCandidate:S W ChengFull Text:PDF
GTID:2481306452971409Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
In the modern equipment manufacturing,the demand for large size,light weight,integration and high efficiency of parts and components is more and more intense.However the traditional manufacturing process is greatly affected by factors such as high equipment requirements,high energy consumption,serious material waste,and mold design which reduced structural development efficiency.Based on the dispersion-deposition principle,the technology of wire and arc additive manufacturing(WAAM)used arc as the heat source to melt the welding wire and deposited metal to build three-dimensional solid mold component up layer by layer along the specific path.Compared with the traditional steel structure manufacturing process,it not only has the advantages of low production cost,low material waste,short manufacturing cycle,etc.,but also can process the manufacture of complex cavity structure and hollow closed structure.Therefore,it is of great scientific significance and engineering value to study the basic process and theory of WAAM technology and explore its engineering application feasibility in the manufacture of structural parts.In this paper,the welding wire of ER70-G(GB standard)model is used as the additive raw material,combine the industrial robot with the digital arc welding power source to process the three-dimensional additive manufacturing of the truss structure parts.The research on the forming process of WAAM lays the foundation for obtaining the reasonable process parameters and the dimensions of the additive layer,planning the additive path of the corresponding structural parts and analyzing the actual additive parts to optimize the additive forming strategy.Firstly,assume that the cross-section contour of the single-layer single-channel additive layer is a circular arc curve by theoretical analysis.The comparison between the actual contour curve and the arc curve obtained by scanning the single-layer single-track additive layer under different process parameters is verified.Assumption.A mathematical model of single-channel multi-layer arc additive superposition is established by comparing the theoretical model of the additive layer and the actual contour.Therefore,the process parameters matching the additive speed and the wire feed speed can be obtained for the actual arc additive manufacturing for different additive wall thicknesses.Secondly,based on the theoretical inter-lane lap joint model,a reasonable additive path planning is carried out for the truss column structural members,and then the arc additive process experiment is carried out under the optimized robot motion trajectory,and the actual structure and theoretical model size are compared by using the three-dimensional scanner.Differences,the results show that the optimized additive path can improve the additive efficiency,reduce the number of lap joints,and improve the dimensional accuracy of the lap joint forming.The final arc additive is used to form a complete truss column structure sample,which meets the structural dimensions and has a suitable machining allowance.Finally,by formulating the additive forming path,substrate and torch attitude of the truss hollow annular structure,a small proportion of truss hollow sealing annular structural parts is formed.The arc process parameters of each layer in the upper ring diameter increasing process were obtained by using the established additive layer inter layer superposition model,and the forming size and surface quality were well controlled.The influence law of the substrate reverse deformation method on the deformation degree of the hollow ring structure is discussed.
Keywords/Search Tags:wire and arc additive manufacturing, contour model, path planning, truss structure
PDF Full Text Request
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