Additive manufacturing (AM) has become an important tool in the product development process as it offers the possibility to produce parts of good geometrical quality within a short period of time, allowing geometrical validations and the visualisation of ideas. Yet the application of AM is often limited due to the poor mechanical properties of AM parts. In the automotive sector for example, there is a high demand for tough AM parts which have an impact strength comparable to industrially moulded thermoplasts. This paper explores the possibility to increase the impact strength of AM parts by combining a stiff, hard and brittle component (VeroWhite Plus in this instance) with a soft, elastomer-like component (TangoBlack Plus) and arranging these on a micro-scale level in form of alternating, chess-pattern voxels. While one material was responsible for maintaining a sufficient stiffness and strength of the resulting composite structure, the other material acted as an obstacle for crack propagation. Varying the edge length of the voxels, it was possible to investigate the influence of the microscopic voxel geometry on the part’s macroscopic impact strength. It was shown that the Charpy impact strength could be raised by a factor of eight (from 10.9 kJ/m2 to values between 80 kJ/m2 and 86.1 kJ/m2) compared to the single material. Above a certain voxel edge length the impact strength decreases again. The critical voxel edge length at which this decrease begins was determined. However, the increase in impact strength is accompanied by a decrease in the glass transition temperature.
Conflict of interest: Authors state no conflict of interest.
Materials and methods
Informed consent: Informed consent has been obtained from all individuals included in this study.
Ethical approval: The research related to human use has been complied with all the relevant national regulations, institutional policies and in accordance the tenets of the Helsinki Declaration, and has been approved by the authors’ institutional review board or equivalent committee.
4. Liu H-C. Near net shape forming of advanced structural ceramic devices. PhD Thesis 2004;68.Search in Google Scholar
6. Chartoff R, Flach L, Weissmann P, 1993. An experimental study of the parameters affecting curl in parts created using stereolithography. In: Proceedings of the Solid Freeform Fabrication Symposium. USA.Search in Google Scholar
7. Croccolo D, De Agostinis M, Olmi G. Experimental characterization and analytical modelling of the mechanical behaviour of fused deposition processed parts made of ABS-M30. Comput Mater Sci 2013;79:506–18.10.1016/j.commatsci.2013.06.041Search in Google Scholar
9. Kruth J-P, Mercelis P, Van Vaerenbergh J, Froyen L, Ruppel ME. Binding mechanisms in selective laser sintering and selective laser melting. Rapid Prototyp J 2005;11:26–36.10.1108/13552540510573365Search in Google Scholar
10. Sood AK, Ohdar RK, Mahapatra SS. Improving dimensional accuracy of fused deposition modelling processed part using grey Taguchi method. Mater Des 2009;30:4243–52.10.1016/j.matdes.2009.04.030Search in Google Scholar
11. Zarringhalam H, Hopkinson N, Kamperman NF, de Vlieger, JJ. Effects of processing on microstructure and properties of SLS Nylon 12. Mater Sci Eng A 2006;435–6:172–80.10.1016/j.msea.2006.07.084Search in Google Scholar
12. Swetly T, Stampfl J, Kempf G, Hucke RM. Elastic properties of additive manufacturing materials for automotive applications. In: Drstvensek I, editor. International conference on additive technologies. Vienna, 2014a: pp. 166–73.Search in Google Scholar
13. Swetly T, Stampfl J, Kempf G, Hucke RM. Capabilities of additive manufacturing technologies (AMT) in the validation of the automotive cockpit. In: RTejournal – Forum Für Rapid Technologie, 2014b: pp. 11/3957.Search in Google Scholar
14. Swetly T, Stampfl J, Kempf G, Hucke RM. Capabilities of additive manufacturing technologies (AMT) in the validation at BMW. In: Rapid.Tech Anwendertagung Für Neue Technologien. Messe Erfurt, 2014c.Search in Google Scholar
15. DIN EN ISO 179-1: Kunststoffe – Bestimmung der Schlageigenschaften – Teil 1: Nicht-Instrumentierte Schlagzähigkeitsprüfung, n.d.Search in Google Scholar
17. Kolednik O, Predan J, Fischer FD, Fratzl P. Bioinspired design criteria for damage-resistant materials with periodically varying microstructure. Adv Funct Mater 2011;21:3634–41.10.1002/adfm.201100443Search in Google Scholar
20. Bechtle S, Fett T, Rizzi G, Habelitz S, Klocke A, Schneider GA. Crack arrest within teeth at the dentinoenamel junction caused by elastic modulus mismatch. Biomaterials 2010;31:4238–47.10.1016/j.biomaterials.2010.01.127Search in Google Scholar PubMed
21. Gronau G, Krishnaji ST, Kinahan ME, Giesa T, Wong JY, Kaplan DL, et al. A review of combined experimental and computational procedures for assessing biopolymer structure – process – property relationships. Biomaterials 2012;33:8240–55.10.1016/j.biomaterials.2012.06.054Search in Google Scholar PubMed PubMed Central
24. Yang W, Sherman VR, Gludovatz B, Mackey M, Zimmermann EA, Chang EH, et al. Protective role of arapaima gigas fish scales: structure and mechanical behavior. Acta Biomater 2014;10:3599–614.10.1016/j.actbio.2014.04.009Search in Google Scholar PubMed
25. Wang DL, Lau J, Soane NV, Rosario MJ, Boyce PM. Mechanical Behavior of Co-Continuous Polymer Composites. In: Proulx T, editor. Experimental and applied mechanics. Vol 6, Conference Proceedings of the Society for Experimental Mechanics Series. New York: Springer, 2011: pp. 801–4.Search in Google Scholar
26. Sen D, Buehler MJ. Atomistically-informed mesoscale model of deformation and failure of bioinspired hierarchical silica nanocomposites. Int J Appl Mech 2010;02:699–717.10.1142/S175882511000072XSearch in Google Scholar
27. Sen D, Buehler MJ. Structural hierarchies define toughness and defect-tolerance despite simple and mechanically inferior brittle building blocks. Sci Rep 2011;1:35.10.1038/srep00035Search in Google Scholar PubMed PubMed Central
28. Dimas LS, Bratzel GH, Eylon I, Buehler MJ. Tough composites inspired by mineralized natural materials: computation, 3D printing, and testing. Adv Funct Mater 2013;23:4629–38.10.1002/adfm.201300215Search in Google Scholar
29. Fratzl P, Gupta HS, Fischer FD, Kolednik O. Hindered crack propagation in materials with periodically varying Young’s modulus – Lessons from biological materials. Adv Mater 2007;19:2657–61.10.1002/adma.200602394Search in Google Scholar
30. DIN EN ISO 53504: Prüfung von Kautschuk und Elastomeren – Bestimmung von Reißfestigkeit, Zugfestigkeit, Bruchdehnung und Spannungswert im zugversuch, n.d.Search in Google Scholar
31. Rodrigues SA Jr, Ferracane JL, Della Bona A. Flexural strength and Weibull analysis of a microhybrid and a nanofill composite evaluated by 3- and 4-point bending tests. Dent Mater 2008;24: 426–31.10.1016/j.dental.2007.05.013Search in Google Scholar PubMed
34. Swetly T. Capabilites of the application of Additive Manufacturing in the validation of the automotive instrument panel and centre console. Doctoral thesis. Vienna University of Technology 2016.Search in Google Scholar
35. Warkentin M. Beeinflussung von Materialeigenschaften 3D-gedruckter Bauteile durch gezielte Kombination von Materialien unterschiedlicher Eigenschaften. Bachelor Thesis. University of Applied Sciences Landshut 2015.Search in Google Scholar
36. Willing M. Parametrische Steuerung von Materialeigenschaften additiv produzierter Strukturbauteile. Diploma Thesis. University of Technology Dresden 2014.Search in Google Scholar
©2016 Walter de Gruyter GmbH, Berlin/Boston