基于扫描线的增材制造表面形状偏差形成机理研究

增材制造（AM）通过一定方式沿着既定扫描线形成每一层的实体，以逐层打印的方式得到零件。但其生产过程中材料具有一定流动性，喷射速度、打印温度、构型方向等众多工艺因素都会影响实际扫描线赋型实体，造成的偏差沿构造方向逐层叠加，最终造成零件的表面形状偏差。直接分析几何偏差成因对AM零件整体的影响无法从机理角度准确地展开研究。因此，本项目将从AM零件表面形状偏差形成机理的角度出发，利用AM零件成型特点，分析和研究在给定工艺参数条件下的扫描线赋型规律；构建扫描线中的“轮廓线”、“填充线”与零件“已完成表面”、“过渡表面”的几何及其偏差坐标系的映射关系；在考虑增材制造中“误差复映”现象的情况下，实现表面几何偏差叠加计算方法。该研究将解决通过工艺参数对增材制造表面几何偏差难以预估的问题，为AM零件制造过程中的质量保证和设计过程中提供面向制造的评估反馈提供使能技术，为进一步推动增材制造技术发展做出贡献。

Additive Manufacturing forms each layer along a given scanning toolpath, producing parts by layer-upon-layer method. Since the material in additive manufacturing has fluidity, factors such as jet speed, printing temperature, printing orientation will affect the actual scanning line and its forming entity, making the deviation increasing along the printing orientation and resulting in the surface shape deviation. Direct analysis of the geometrical deviation influence on the additive manufacturing parts could not be accurately carried out from the perspective of mechanism. Therefore, this project proposes to analyze the influence of different factors on the surface shape deviation of additive manufacturing part from the perspective of scanning toolpath. A process based method of surface geometric deviation description is proposed, in which the mapping relation between "contour line", "filling line" and geometrical deviation coordinate system of "finished surface", "transition surface" is constructed. Then, considering the "error remapping" phenomenon in additive manufacturing, a superposition method to analyze surface geometrical deviation is proposed to study the formation mechanism of surface shape deviation of additive manufacturing part. This study could be used for providing tools for quality insurance and quality assessment. Consequently, enable the DFM for additive manufacturing and contribute to the application and development of additive manufacturing.