微纳增材制造微圆柱结构的形貌分析与工艺优化研究

针对目前亚像素微扫描的LCD式光固化3D打印技术在微纳结构增材制造中存在的典型打印瑕疵，通过优化打印工艺和分析打印结构，以提高打印成型质量和生产效率。首先，通过对打印材料后处理工艺研究，设计单因素试验并打印平板模型，分析后固化时长对零件硬度、粗糙度及形貌影响规律。其次，结合打印工艺参数，设计正交试验并打印圆柱阵列模型，分析打印层厚、曝光时间、振动次数对微圆柱成型的影响规律。结果表明：后固化时间在5～10 min时，后固化效果最优，此时表面粗糙度Ra值约为29 nm，邵氏硬度在88 HD左右。打印工艺参数对微圆柱直径尺寸影响大小排序为：曝光时间>打印层厚>振动次数。在均衡打印质量和打印效率的前提下，打印参数优化后，打印直径50 μm，高度210 μm的微圆柱结构应采用打印层厚10 μm，曝光时间2 500 ms，振动次数64 x的打印工艺参数。

Morphology Analysis and Process Optimization of Micro-cylinder Structure in Micro-nano Additive Manufacturing

In view of the typical printing defects existing in the micro-nano structure additive manufacturing of sub-pixel microscanning LCD photocuring 3D printing technology, it is devoted to optimize the printing process and analyzed the printing structure to improve the printing quality and production efficiency. Firstly, the post-treatment time is determined by designing the single factor test and printing model, and the influence of post-curing time on the hardness, roughness and morphology of parts is analyzed. Secondly, combined with the printing process parameters, the orthogonal test and printing cylinder array model are designed to analyze the influence of printing layer thickness, exposure time and vibration times on the forming of micro-cylinder. The results show that the best curing effect is obtained when the curing time is 5~10 min, and the surface roughness Ra is about 29 nm and shore hardness is about 88 HD. The influence order of printing process parameters on the diameter of micro-cylinder is exposure time, print layer thickness and number of vibrations. Under the premise of balanced printing quality and printing efficiency with optimized printing parameters, the micro cylinder with diameter of 50 μm and height of 210 μm can be well printed under the print layer thickness of 10 μm, the exposure time of 2 500 s and the number of vibrations is 64 x.