Fig. 1 Variation in the viscosity of the alumina slurries with 20, 25 and 30 vol% initial solid loadings with shear rate

Fig. 2 Microstructures of the sintered Al2O3 preform with 30 vol% initial solid loading and the Al-Mg-Si/Al2O3 composite. a-d Horizontal sections at different locations away from the bottom rod; e Vertical section of the entire perform; f Vertical section of the Al-Mg-Si/Al2O3 composite (in the upper part); g XRD pattern of the Al-Mg-Si/Al2O3 composite

Fig. 3 Influence of initial solid loading on the wavelength (λ) a, wall thickness (δ) b of the alumina scaffolds at different locations

Fig. 4 SEM image of the Al-Mg-Si/Al2O3 composite with 25 vol% initial solid loading at the intermediate height a, the magnified image of the framed area in a b, and the elemental mapping graphs of elements Mg c, Al d, Si e, O f corresponding to b

Fig. 5 Variations in compressive stress with strain for the sintered Al2O3 preforms a, the Al-Mg-Si/Al2O3 composites b with different initial solid loadings

Fig. 6 Optical micrographs showing the lamellar structures in the different regions of the Al-Mg-Si/Al2O3 composite with 25 vol% initial solid loading: a upper part; b middle part; c lower part

Fig. 7 Fractographs of the Al-Mg-Si/Al2O3 composites with different Al2O3 loadings: a 20 vol% (upper part); b 25 vol% (upper part); c 30 vol% (upper part); d 30 vol% (lower part)