Simulation And Experimental Study Of Laser Irradiation Temperature Field Based On Frozen Slurry 3D Printing

Ceramic materials have a series of excellent properties,such as high temperature resistance,high strength,corrosion resistance and stable physical and chemical properties.Especially in recent years,with the development of new materials and manufacturing technology,special ceramics such as functional ceramics and engineering ceramics have emerged,ande ceramic materials are widely used in aerospace,biomedical,electronic industry and other high-end fields.As soon as 3D printing technology came out,it attracted much attention from domestic and foreign scholars.Today,this technology has been maturely applied in polymer and metal fields.However,due to the unavoidable shortcomings of ceramic materials such as higher hardness,brittleness and high melting temperature,it is difficult to directly apply the methods which has mature applications in polymer and metal fields to ceramic field.In this paper,based on the analysis of the advantages and disadvantages of existing ceramic 3D printing methods,a new idea of rapid prototyping of ceramics by using freeze-fixing principle and laser scanning thermal effect is proposed.And according to the difference of laser scanning path and ceramic slurry forming mechanism,two new frozen slurry-based ceramic 3DP methods,FS-LOM and FS-LSC,are carried out.By a large number of experiments,the feasibility of laser scanning forming of ceramic materials based on frozen slurry is verified.In order to further explore the influence of laser processing parameters on the fonning results in the two forming methods,based on the heat conduct theory,a three-dimensional transient physical model of frozen ceramics irradiated by laser with Gauss distribution is established in direct-coupling analysis software for multi-physical fields named COMSOL Multiphysics.The temperature distribution nephogram of the material surface and the temperature distribution curve of the central point of the material surface along the parallel direction of the coordinate axis are obtained.Calcuated the structure size of laser scanning area,and found both the depth and width of laser curing/cutting increase with the increase of laser power or the decrease of scanning rate.Appropriate increase of power and scanning rate can improve the processing efficiency under the condition that the solidification/cutting depth is satisfied.Finally,with the theoretical guidance of simulation results,the experiment of laser scanning freezing ceramic slurry is carried out.FS-LOM experiment with CMC-Na frozen ceramic slurry with solid content of 50%and FS-LSC experiment with water glass frozen ceramic slurry were carried out respectively.By scanning electron microscopy(SEM)observed the microscopic morphology of formed samples,measured and recorded its structure size.After compered with the simulation results,the processing parameters of the two forming methods are determined.