Effect of Fe2O3 on Compressive Strength and Microstructure of Porous Acicular Mullite

Omerašević, Mia; Krsmanović, Miomir; Adamović, Nada; Wang, Chang-An; Bučevac, Dušan

doi:10.3390/ceramics8030111

Open AccessArticle

Effect of Fe₂O₃ on Compressive Strength and Microstructure of Porous Acicular Mullite

by

Mia Omerašević

¹

,

Miomir Krsmanović

¹

,

Nada Adamović

¹

,

Chang-An Wang

^2,*

and

Dušan Bučevac

^1,*

¹

Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, 11000 Belgrade, Serbia

²

State Key Lab of New Ceramic Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China

^*

Authors to whom correspondence should be addressed.

Ceramics 2025, 8(3), 111; https://doi.org/10.3390/ceramics8030111

Submission received: 9 August 2025 / Revised: 2 September 2025 / Accepted: 4 September 2025 / Published: 5 September 2025

(This article belongs to the Special Issue Ceramic Materials for Industrial Decarbonization)

Download

Browse Figures

Versions Notes

Abstract

Porous acicular mullite was fabricated at 1300 °C starting from Al₂O₃ and mixture of SiO₂ and MoO₃ obtained by previous oxidation of waste MoSi₂. It was found that the presence of MoO₃ favors formation of acicular (prism-like) mullite grains with sharp edges. The effect of addition of Fe₂O₃ (4–12 wt.%) on phase composition, compressive strength, thermal conductivity and microstructure was studied. The addition of Fe₂O₃ improved the compressive strength from approximately 25 MPa in pure mullite to about 76 MPa in samples containing 12 wt.% Fe₂O₃, while the open porosity decreased from 55.4% to 51.8%. The presence of Fe₂O₃ caused a decrease in mullite formation temperature owing to the formation of liquid phase and accelerated diffusion. The solubility of iron oxide in mullite lattice was between 8 and 12 wt.% Fe₂O₃. The incorporated iron ions also promoted the rounding of sharp edges in prismatic mullite grains, leading to a reduced specific surface area of 0.55 m²/g in the sample with 12 wt.% Fe₂O₃. The thermal conductivity of mullite increased with addition of 12 wt.% Fe₂O₃ reaching value of 1.17 W/m·K.

Keywords: porous mullite; sintering; gas filtration; compressive strength; microstructure

Share and Cite

MDPI and ACS Style

Omerašević, M.; Krsmanović, M.; Adamović, N.; Wang, C.-A.; Bučevac, D. Effect of Fe₂O₃ on Compressive Strength and Microstructure of Porous Acicular Mullite. Ceramics 2025, 8, 111. https://doi.org/10.3390/ceramics8030111

AMA Style

Omerašević M, Krsmanović M, Adamović N, Wang C-A, Bučevac D. Effect of Fe₂O₃ on Compressive Strength and Microstructure of Porous Acicular Mullite. Ceramics. 2025; 8(3):111. https://doi.org/10.3390/ceramics8030111

Chicago/Turabian Style

Omerašević, Mia, Miomir Krsmanović, Nada Adamović, Chang-An Wang, and Dušan Bučevac. 2025. "Effect of Fe₂O₃ on Compressive Strength and Microstructure of Porous Acicular Mullite" Ceramics 8, no. 3: 111. https://doi.org/10.3390/ceramics8030111

APA Style

Omerašević, M., Krsmanović, M., Adamović, N., Wang, C.-A., & Bučevac, D. (2025). Effect of Fe₂O₃ on Compressive Strength and Microstructure of Porous Acicular Mullite. Ceramics, 8(3), 111. https://doi.org/10.3390/ceramics8030111

Article Menu

Effect of Fe₂O₃ on Compressive Strength and Microstructure of Porous Acicular Mullite

Abstract

Share and Cite

Article Metrics

Article Access Statistics

Further Information

Guidelines

MDPI Initiatives

Follow MDPI