Research On 3D Printer Control System Based On Micro-flow Extrusion Forming Process

Ceramic materials are widely used in medical dental prosthetics,aerospace and other fields due to its high hardness and corrosion resistance.However,traditional ceramic manufacturing processes can no longer meet the market demand for mass production and personalized customization at this stage.With the popularization of new manufacturing processing technology,additive manufacturing(AM)technology has played its own advantages in the field of processing and manufacturing of complex ceramic parts,among which micro-flow extrusion process has been widely concerned by domestic and foreign research teams due to its simple forming principle and low equipment cost.However,for the control system of micro-flow extrusion 3D printer,there are still shortcomings in the study of extrusion printing forming control strategy,such as the unreasonable matching between the scanning speed of the forming platform and the extrusion speed of the slurry,and the unstable extrusion pressure of the slurry.Aiming at the micro-flow extrusion forming process,this paper studied the print forming control strategy and developed a 3D printer control system based on STM32.The main research work of this paper is as follows:(1)According to the analysis of the forming principle of micro-flow extrusion process,the overall structural framework of the micro-flow extrusion 3D printer control system was designed.In order to achieve the goal of smooth printing and forming of ceramic slurry with high solid content,the selection principles of software modules and hardware modules of the control systems were proposed,and the data processing flow of printing process was studied and analyzed.(2)The inflection point transition model of the forming platform at the junction of the scanning path was established,and the matching algorithm for the scanning speed of forming platform of 3D printing equipment and the extrusion speed of slurry was proposed.The space motion laws of forming platform of the 3D printing equipment was analyzed,the scanning path is connected by multiple straight segments with different lengths,according to the difference of the connecting corners of the scanning path,the inflection point transition model was established.Taking the scanning speed curve of the forming platform as a reference,the matching method of scanning speed and extrusion speed was studied,the scanning speed and the extrusion feed speed was matched by the speed matching factor,and the correctness and reliability of the speed matching algorithm were verified through related experiments.(3)A prediction method of slurry extrusion pressure was designed,and a slurry extrusion pressure stabilization controller suitable for micro-flow extrusion was constructed.Based on the analysis of the extrusion rheological characteristics of ceramic slurry in the process of micro-flow extrusion printing,a prediction model of slurry extrusion pressure was established,and a prediction method for obtaining the pressure curve by simulating the actual slurry extrusion process and obtaining the reference pressure by multi-segment straight line fitting was proposed.Based on the traditional PID control principle,a pressure stabilization controller suitable for micro-flow extrusion process was designed,the feasibility and accuracy of the slurry extrusion pressure prediction method and pressure stabilization control strategy were verified by the printing and forming experiments of the ceramic blank sample.