HOFER: Texturing 3D printed alumina ceramics through templated grain growth
Channel: Chair of Structural and Functional Ceramics
Date: 2021-04-23

[Title]
Texturing 3D printed alumina ceramics through templated grain growth

[Authors]
Anna-Katharina HOFER
Irina KRALEVA
Martin SCHWENTENWEIN
Raul BERMEJO

[Event]
96th Annual meeting of the German ceramic society (DKG)
Monday, 19th April 2021

[Abstract]
Texturing the microstructure may enhance the structural and/or functional properties of polycrystalline ceramics. For instance, nacre-like alumina has been fabricated through different processing routes (e.g. tape casting), using Templated Grain Growth (TGG) as a strategy to obtain high degree “morphological” and “crystallographic” texture. However, a limitation of these methods is the rather simple geometries that can be fabricated, e.g. discs or plates.
Additive manufacturing techniques have proved successful in fabricating 3D monolithic structural and functional ceramics of complex geometries. In this work, we explore the possibility of fabricating textured microstructures using the 3D-printing based on lithography-based-ceramic-manufacturing (LCM). A commercially available α-alumina slurry was employed to fabricate the equiaxed alumina (EA) reference material. For textured alumina (TA) samples, the slurry was modified with α-alumina templates. TGG during sintering led to textured grains with preferential crystallographic orientation. Density, microstructure, and the effect of sintering time on grain growth were analysed in TA and compared to EA samples.
The use of LCM-process for template alignment together with TGG during sintering for grain growth resulted in a high degree of grain orientation in alumina, reaching a Lotgering Factor of approximately 80 %, with relatively low porosity (approx. 7 %). The alignment of templates was facilitated through the torque occurring when the slurry is distributed after every printing step as well as the immersion of the building platform into the slurry bed. This approach opens the path for 3D printing textured ceramics with complex architectures.