Shape and Performance Controlled Advanced Design for Additive Manufacturing: A Review of Slicing and Path Planning

Additive manufacturing (AM) brings out a revolution of how the products are designed and manufactured. To obtain desired components, advanced design for additive manufacturing (ADfAM) is widely emphasized in geometry, material, and function design. 3D slicing and path planning, which are the critical steps of ADfAM, directly determine manufacturing process variables, shape, and performance of printed parts. For widely used planar slicing, the contradiction between accuracy and build time has attracted considerable attention and efforts, leading to various novel and optimization methods. Nevertheless, curved surfaces and slopes along the build direction constrain the surfaces to be smooth due to the inherent staircase effect of AM. Meanwhile, there is significant anisotropy of the printed piece making it sensitive to any shear (or bending) stress. Moreover, support structures for the overhang part are necessary when building along one direction, resulting in time-consuming and cost-expensive process. Due to the rapid development of 3D slicing and path planning, and various newly proposed methods, there is a lack of comprehensive knowledge. Notwithstanding, there are fewer literature reviews concerning planar slicing and filling strategy. Less attention has been paid to non-planar slicing, path planning on curved surfaces, and multi-degree of freedom (DOF) AM equipment, as well as printing under pressure. Hence, it is significant to get a comprehensive understanding of current status and challenges. Then, with suitable technologies, the printed parts with improved surface quality, minimum support structures, and better isotropy could be acquired. Finally, the recommendation for the future development of slicing and path planning is also provided.