Additive Manufacturing of Functionally Graded Ceramic Materials by Stereolithography

Abstract

An additive manufacturing technology is applied to obtain functionally graded ceramic parts. This technology, based on digital light processing/ stereolithography, is developed within the scope of the CerAMfacturing European research project. A three-dimensional (3-D) hemi-maxillary bone-like structure is 3-D printed using custom aluminum oxide polymeric mixtures. The powders and mixtures are fully analyzed in terms of rheological behavior in order to ensure proper material handling during the printing process. The possibility to print functionally graded materials using the Admaflex technology is explained in this document. Field-emission scanning electron microscopy (FESEM) show that the sintered aluminum oxide ceramic part has a porosity lower than 1% and no remainder of the original layered structure is found after analysis.

3Y-TZP DLP Additive Manufacturing: Solvent-free Slurry Development and Characterization

“…It is important to note that the three studies that achieved these characteristics used solvent-based slurries. Another interesting point is that the zirconia powders used in the related literature have a specific surface area between 6 and 9 m 2 /g, as seen by the labels in Figure 1, consistent with the protocol for the development of photocurable ceramic suspensions created by Gonzalez et al 30 which suggests that the specific surface area should be around 7 m 2 /g. Other related works that used alumina 26,31 or piezoelectric material 17 also follow this trend.…”

“…HDDA has been used in association with other monomers such as ethoxylated pentaerythritol tetraacrylate (EPTA) 19,20 , polyethylene glycol diacrylate PEGDA 17 , ethoxylated pentaerythritol tetraacrylate (PPTTA) [21][22][23] , and 1,1,1-Trimethylol propane triacrylate (TMPTA) 4, 24,25 , or as a single monomer [26][27][28] . Moreover, an appropriate photoinitiator must be chosen to initiate the photopolymerization reactions, considering mainly its compatibility with the adopted monomers and the relationship between its light absorption spectrum and the wavelength emitted by the light source 29,30 . Lastly, the hydrophilic character of the ceramic particles requires the use of suitable dispersants to promote efficient dispersion in non-polar resins 31 .…”

Obtenção de cerâmicas de alumina com porosidade graduada processadas pelas técnicas de colagem de barbotina e freeze casting

“…Atualmente, também vêm sendo estudados materiais com porosidade graduada, nos quais a porosidade se altera ao longo de uma das dimensões do material [45][46][47][48]. Estes materiais são denominados materiais com gradiente funcional (MGF), pois apresentam propriedade e/ou composição que variam dentro do volume do material [49][50][51][52]. Esses materiais começaram a ser estudados há mais de 40 anos, a fim de solucionar problemas de aplicação de engenharia [53].…”

“…A produção de MGFs porosos pode ser feita utilizando diferentes técnicas, como por exemplo, coprensagem, tape casting, freeze casting e colagem de barbotina. Os materiais produzidos podem apresentar porosidade em quantidades variáveis, tendo poros com formatos e tamanhos diferentes, o que pode gerar um gradiente de dureza, densidade, condutividade térmica, ou módulo de elasticidade na extensão do material [45][46][47][48][49][50][51][52][53][54][55][56], o que permite um vasto espectro de possibilidades de aplicação. Assim, o objetivo desse trabalho foi produzir cerâmicas de alumina com gradiente de porosidade obtidas por dois processos: colagem de barbotina sequencial utilizando hidróxido de alumínio como agente porogênico e processo de freeze casting, utilizando congelamentos sequenciais.…”

Rheology and processing of UV‐curable textured alumina inks for additive manufacturing

“…Conventional alumina parts can be 3D printed by a variety of techniques including powder bed binder jetting, direct ink write, and sterolithography 15 . Commercial stereolithography systems by Lithoz (Lithoz GmbH, Vienna, Austria), 3DCeram (3DCeram SAS, Limoges, France), and Admatec (Admatec Europe BV, Alkmaar, Netherlands) have demonstrated production of >99% dense alumina parts with a feature resolution down to 200 µm 16,17,18,19 . Addition of a controllable texturing mechanism to the printer could enable simultaneous shape and microstructure control on demand.…”