The Research Of The Micro-structure Additive Manufacturing Based On Stereolithography

Stereolithography is an additive manufacturing method with high precision and manufacturing speed.To obtain 3D structures,the photo polymer is solidified under the light with specific wavelength in a layer-by-layer way.According to the principle,factors which determine the accuracy of stereolithography include the slicing method,the optical system and the photo polymer.Therefore,it has been a key point to analyze the methodology of improving the precision of stereolithography in additive manufacturing engineering.Present researches mainly focus on the effect of the optical system and the precision of resin solidification on the accuracy of the overall model.But on the basis of the principle of light curing,the forming precision is limited by the molding size,and the larger the forming area,the lower the forming precision.There's a lack of deep research of additive manufacturing in a large area with specific precision.This article adopts the combination of theoretical analysis,mathematical modeling and experiments to analyze the effect laws of additive manufacturing of microstructures with high precision up to 15?m using stereolithography,and realizes the manufacturing of large models up to 10×15×15mm~3 at the same time.The specific contents of the research include the following aspects:The high resolution imaging characteristics of the light path were studied.and a stitching technology to expand the fabrication area with precision maintained was put forward.Influences of light path parameters on precision was analyzed.The model of optical system was constructed and simulating analyzed through the optical simulation software Zemax.In the optical system,the device selection and the construction of the system was completed,and the system was verified experimentally to meet the technical requirements,laying a foundation for the subsequent manufacturing of models in large area.The control system was constructed based on the hardware.The coherent control and setup of the projection system and the moving system was accomplished.Meanwhile for the stitching method,the patterns segmentation was completed based on pixels' density of different patterns preprocessing.To improve the molding rate of the curing model and the printing quality,a real-time monitoring system was introduced,and the contour of finished model was detected.The research of stereolithography was carried out experimentally,investigating the influence factors of horizontal precision and vertical precision.Proper reaction parameters were determined subsequently,such as the cure depth,the light intensity,and the exposure time.Meanwhile the problems existing in the experiments were analyzed and solved by establishing mathematical models,which improves the quality of the stitching.Finally a precision of the whole system up to ±5.5?m,a fabrication area of 10×15×15mm~3 were achieved,which satisfies the technical requirements.The experiment to fabricate assembly at one time was performed,and problems in the process was analyzed,followed by corresponding solutions putting forward.