Designing for Additive Manufacturing - Product and Process Driven Design for Metals and Polymers

Additive Manufacturing (AM) has broken through to common awareness and to wider industrial utilization in the past decade. The advance of this young technology is still rapid. In spoken language additive manufacturing is referred as 3D printing for plastic material and additive manufacturing is left as an umbrella term for other materials i.e. metallic materials and ceramics. As the utilization of AM becomes more widespread, the design for additive manufacturing becomes more crucial as well as its standardization. Additive manufacturing provides new set of rules with different design freedom in comparison with subtractive manufacturing methods. This is thought to empower product driven designs. However, in the AM methods there are process driven variables that limit the designs functions to what could be manufactured. There are often extra steps after production to finalize the design. Topology optimization utilizes product driven design where material is only where it is needed to be. The design is computed without taking into account any manufacturing constrains and only the design in the final application stage is achieved. Topology optimization algorithm is explored in detail for two algorithms. Then these algorithms are compared in case study I to gain better understanding of the algorithms functions. Case study I consists of 2D and 3D algorithms where a 3D level set method algorithm was written for this purpose. The concept of designing for additive manufacturing is examined for polymeric materials in case study II with a help of topology optimization design software tailored for additive manufacturing market. The parts are manufactured with different AM methods, examined and results are explained. The results show an interesting effect of anisotropy and the manufacture methods effect in the part mechanical properties. On the other hand, process driven design and its concepts important as the manufacturing method dictates, what can and should be done economically. Metal AM process constraints are explored in case study III through accuracy studies in metal additive manufacturing at laser powder bed fusion (LPBF) technology. Accuracy and surface studies are concluded to gain a better understanding of the process and manufacturability of metal parts. The gain knowledge is explaned and examples are shown how these are utilized to make metal parts with tailored properties and with minimal post processing needs.