锌铝合金熔融三维直写成形尺寸建模与组织分析OA北大核心CSTPCD

In order to realize the control of shape and performance of metal melting 3D direct writing process,modeling and microstructure analysis of three-dimension direct writing for zinc-aluminum alloy were carried out.Firstly,based on the minimum control unit test of zinc-aluminum alloy melt direct writing,the trace width was fitted by multiple nonlinear regression method.Forming characteristic parameter w was used as response variable in the regression analysis,and the forming parameters D and H were used as the predictive variables.Secondly,the single-track forming dimension parameter model under different process parameters was established,and the fitting degree of the model was verified.Finally,multi-phases flow model was adapted to build the coupled calculative models for direct writing deposition and solidification.Typical solidification microstructures in the forming process were analyzed.By introducing remelting preparation time tr,the process parameters with good bonding effect between layers in forming were predicted and calculated.The results show that in the single-track forming dimension parameter model,the nozzle diameter D is the first factor affecting the width of the forming channel,followed by the height of the nozzle from the forming bottom plate H.When the trace width is approximately equal to the width of the solidification layer,it is the best time to form the next layer.