Speaker
Description
Texturing the microstructure may enhance the structural and/or functional properties of polycrystalline ceramics. For instance, nacre-like textured alumina obtained through tape casting using Templated Grain Growth (TGG) has been established 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 feasibility of fabricating textured microstructures using 3D-printing based on lithography-based-ceramic-manufacturing (LCM) technology. A commercially available α-alumina slurry was employed to fabricate the equiaxed alumina (EA) reference material. For textured alumina (TA), the slurry was modified with α-alumina templates. The alignment of templates during the printing process was facilitated through shear forces, occurring through slurry distribution after every printing step. TGG during sintering led to textured grains with preferential crystallographic orientation. Density, microstructure and Ball-on-Three-Ball bending strength were analysed in TA and compared to EA samples.
The use of LCM-process for template alignment together with TGG during sintering resulted in a high degree of grain orientation in alumina, reaching a Lotgering Factor of approximately 0.80, with relatively low porosity (approx. 7 %). The evaluated characteristic strength (σ0) was 640 MPa and 570 MPa for TA and EA samples, respectively. This successful approach opens the path for 3D printing textured ceramics with complex architectures.
| Speaker Country | Österreich |
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