To take advantage of AM, designers need a good understanding of the manufacturing constraints imposed by the various AM fabrication methods. For this purpose, DFM needs to reflect the typical characteristics of AM:
Layer-by-layer material deposition compounded with direct fabrication from CAD model opens up the realm of component design. Unlike more conventional substractive and formative processes, additive methods can build a wide range of geometries.
Parts could advantageously be designed as 3D customisable puzzles with optional modules. These modules can be built separately and assembled while taking advantages of alternative technology-specific designs to minimise manufacturing difficulties and enhance functionalities.
This type of hybrid manufacturing method can be divided into two categories:
- 1) a combination of AM methods [8, 9] where, for instance, stereolithography provides substrate/mechanical structure while interconnections were achieved using direct write of conductive inks.
- 2) a mix of AM and conventional methods [10, 11] such as selected laser melting (SLM) combined with CNC machining, etc.
Using AM technologies, materials can be processed selectively. Complex material compositions can be tailored with functional property gradients or heterogeneous lattice structures differentiated by their density.
Researchers report three typical features:
- tailored nano-/micro-structures,
- textures added to surfaces of parts
- and cellular materials (materials with voids), including foams, honeycombs, and lattice structures.
A few AM processes make it possible to remanufacture and repair components at low cost and relative high speed. For instance, the LENS process is used to repair the worn area of a Ti-6Al-4 V bearing housing from a gas turbine engine. Followed up by conventional CNC machining, the repair costs amount to only 50 % of the price of new component and saves the materials required to manufacture a new bearing housing.
Get Inside Metal Additive Manufacturing:
• Understand metal AM technologies and their specific applications;
• Stay up-to-date with the latest developments in materials research for metal-based AM;
• Get tested parameters for the manufacture of actual components;
• Follow real-world case studies in re-design for AM;
• Dig deeper into the fundamentals of AM processes;
All of it distilled from academic research into bite-size posts!
1.Sheng Yang & Yaoyao Fiona Zhao, Additive manufacturing-enabled design theory and methodology: a critical review, Int J Adv Manuf Technol. DOI 10.1007/s00170-015-6994-5
2. Gibson I, Rosen DW, Stucker B (2010) Additive Manufacturing technologies: rapid prototyping to direct digital manufacturing. Springer, US
3. Watts D, Hague R (2006) Exploiting the design freedom of RM. In: Proceeding of the solid freeform fabrication Symp., Austin, TX, August 14-16, Cambridge University Press, pp 656-667
4. Hague R, Mansour S, Saleh N (2003) Design opportunities with rapid manufacturing. Assem Autom 23(4):346–356
5. Hague R,Mansour S, Saleh N (2004)Material and design considerations for rapid manufacturing. Int J Prod Res 42(22):4691–4708
6. Hague R, Campbell I, Dickens P (2003) Implications on design of rapid manufacturing. Proceedings of the Institution of Mechanical Engineers, Part C. J Mech Eng Sci 217(C1):25–30
7. Hague R (2006) Unlocking the design potential of rapid manufacturing. In: Hopkinson N, Hague R, Dickens P (eds) Rapid manufacturing: an industrial revolution for the digital age. Wiley, USA8. Perez KB, Williams CB Combining additive manufacturing and direct write for integrated electronics—a review. In: 24th International Solid Freeform Fabrication Symposium—An Additive Manufacturing Conference, SFF 2013, August 12,
2013 - August 14, 2013, Austin, TX, United states, 2013. 24th International SFF Symposium—An Additive Manufacturing Conference, SFF 2013. University of Texas at Austin (freeform), pp 962–979
9. Lopes AJ, MacDonald E, Wicker RB (2012) Integrating stereolithography and direct print technologies for 3D structural electronics fabrication. Rapid Prototyp J 18(2):129–143
10. Palmer J, Jokiel B, Nordquist C, Kast B, Atwood C, Grant E, Livingston F, Medina F, Wicker R (2006) Mesoscale RF relay enabled by integrated rapid manufacturing. Rapid Prototyp J 12(3):148–155
11. Kerbrat O, Mognol P, Hascoët JY (2011) A new DFM approach to combine machining and additive manufacturing. Comput Ind 62(7):684–692
12. Rosen DW (2007) Computer-aided design for additive manufacturing of cellular structures. Comput-Aided Des Applic 4(5):585–594
13. Choi J-W, Yamashita M, Sakakibara J, Kaji Y, Oshika T, Wicker RB (2010) Combined micro and macro additive manufacturing of a swirling flow coaxial phacoemulsifier sleeve with internal micro- vanes. Biomed Microdevices 12(5):875–886