Manufacturing complex Al₂O₃ceramic structures using consumer-grade fused deposition modelling printers

Abstract

<jats:sec> <jats:title content-type="abstract-subheading">Purpose</jats:title> <jats:p>This study aims to fabricate complex ceramic tetrahedron structures, which are challenging to produce by more conventional methods such as injection molding. To achieve this aim, thermoplastic-ceramic composite filaments were developed and printed with unmodified, consumer-grade, fused deposition modelling (FDM) printers instead.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Design/methodology/approach</jats:title> <jats:p>Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> ceramic powder was mixed with ethylene vinyl acetate polymer as a binder (50 Vol.- per cent) to form a filament with a constant diameter of 1.75 mm. After the printing and thermal treatment stages, the shrinkage and mechanical properties of cuboid and tetrahedron structures were investigated.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Findings</jats:title> <jats:p>The shrinkage of the parts was found to be anisotropic, depending on the orientation of the printing pattern, with an increase of 2.4 per cent in the (vertical) printing direction compared to the (horizontal) printing layer direction. The alignment of the ceramic particle orientations introduced by FDM printing was identified as a potential cause of the anisotropy. This study further demonstrates that using a powder bed during the thermal debinding process yields sintered structures that can withstand twice the compressive force.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Originality/value</jats:title> <jats:p>Ceramic FDM had previously been used primarily for simple scaffold structures. In this study, the applicability of ceramic FDM was extended from simple scaffolds to more complex geometries such as hollow tetrahedra. The structures produced in this study contain dense parts printed from multiple contiguous layers, as compared to the open structures usually found in scaffolds. The mechanical properties of the complex ceramic parts made by using this FDM technique were also subjected to investigation.</jats:p> </jats:sec>

Bending Properties of Lightweight Copper Specimens with Different Infill Patterns Produced by Material Extrusion Additive Manufacturing, Solvent Debinding and Sintering

“…The material with a liquid-like consistency is pushed through a die and then selectively deposited, layer-by-layer, to shape a threedimensional object [15]. MEX allows the production of complex-shaped parts not only from thermoplastics [20], fiber-filled composites [21], and low melting point (~450 • C) metallic alloys [22], but also from high-melting-point (>1000 • C) metallic alloys [15,[23][24][25][26][27][28][29][30], such as copper [31], ceramics [15,[32][33][34][35][36][37][38][39], and hard metals and cermets [40][41][42]. Highly-filled thermoplastic filaments are used as the feedstock material to obtain metallic, ceramic and cermet parts.…”

Influence of the Infill Orientation on the Properties of Zirconia Parts Produced by Fused Filament Fabrication

“…The feedstock is a multicomponent polymer system highly filled with powder of the desired ceramic material [ 9 , 11 , 12 , 13 ]. Once the so-called green parts are shaped by FFF, the polymer components are removed in the debinding stage by a catalytic reaction [ 14 ], dissolution in a solvent [ 12 , 15 , 16 ] and/or thermal decomposition [ 9 , 17 , 18 , 19 ]. Finally, the parts are sintered to obtain nearly dense components.…”

“…Finally, the parts are sintered to obtain nearly dense components. Some advantages of this technology include the simplicity and the low cost of the equipment required to shape the parts [ 20 ], the possibility to produce lightweight structures with closed geometry [ 19 , 20 , 21 ], the possibility to combine this technology with a well-established process like ceramic injection molding [ 22 ], and the ability to combine various materials in one part by the use of various nozzles [ 23 , 24 , 25 ]. Nevertheless, the use of filaments as feed materials requires tight dimensional tolerances of the filaments to ensure proper feeding [ 8 , 26 , 27 ], which increases its price [ 28 ].…”

Quest for improving service life of asphalt roads

“…Artificial aggregates in the imprinted channels could be hollow tetrahedrons or dolos and tetrapods fabricated with 3D printing, e.g. as complex Al 2 O 3 ceramic structures [22], or with other techniques, still to come. This imprinted channel system should then be covered with a thin waterproof, probably reinforced, black surface layer that is exposed to solar radiation.…”

“…This paper gives examples of selected efforts and research initiatives in that direction during the last decades based on own experience and involvement in projects within the road engineering/sealing components lab at Swiss Federal Laboratories for Material Science and Technology (Empa) [3,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]27] and both the highway/railways engineering and building materials group at Swedish Royal Institute of Technology (KTH) [24][25][26][27][28]. Some of these activities are closely linked to the work within different international technical committees of the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (Rilem), e.g.…”