| Additive Manufacturing (AM) is a layer by layer manufacturing approach for building parts. Additive manufacturing as a technology provides immense design freedom, especially in the field of medical implant design. Revolutionary technologies such as Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) have the potential to customize metal implants to an individual patient. To take advantage of this technology it is important to develop rules that can transform concepts to real world designs. There are many applications that can potentially use additively manufactured cellular structures, but there is a need to provide design guidelines for manufacturability of such structures. This thesis explores the opportunities and challenges in manufacturing high porosity cellular structures, and provides a measure of manufacturability of different cellular structures and design guidelines to improve manufacturability. Cellular structures are defined as structures made from repeating a certain unit cell to form a block, and the characteristic length of each cell is in the range of 0.1 mm to 10 mm. The additive manufacturing technique considered in this work is laser powder bed fusion process (DMLS). This research studies and tests the effect of unit cell type, unit cell size, volume fraction, and orientation on the manufacturability of the cellular structures using experimental builds. Based on these parameters the manufacturability of each cellular structure is evaluated and design guidelines are provided to design and manufacture high porosity cellular structures. |
