Journal of Sol-Gel Science and Technology https://doi.org/10.1007/s10971-020-05300-4 ORIGINAL PAPER: SOL-GEL, HYBRIDS AND SOLUTION CHEMISTRIES The effect of MgO addition on the properties of alumina-based ceramic cores prepared via sol–gel process Shaghayegh Shabani 1 ● Rahim Naghizadeh 1 ● Mohsen Fallah Vostakola 1 ● Farhad Golestanifard 1 Received: 1 November 2019 / Accepted: 17 April 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Alumina-based ceramic cores with MgO addition were prepared using sol–gel process. Prior to magnesia addition, the suitable amount of titania content was determined in the previous research, where it was found that the body with 15wt% titania had the most suitable properties. The effect of magnesia addition on mechanical, physical, thermal, chemical, and microstructural properties of the cores was investigated through adding MgTi 2 O 5 and sintering the bodies at two temperatures (1400 and 1500 °C) for two different soaking times (1 and 2 h). According to the results of flexural strength test, apparent porosity measurement, leaching test, and microstructural properties of the sintered bodies, the body which contained 15wt% titania and 4wt% magnesia had the least sintering shrinkage (~2%), suitable apparent porosity (~30%), acceptable flexural strength (40 MPa), good thermal expansion coefficient (~4.3 × 10 -6 °C -1 ), and also exhibited a suitable leaching behavior. Graphical Abstract Silica sol Al2O3 TiO2/MgO Suspension Mixing and Ball milling Casting Drying Sintering Initiator (NH4Cl) Gelation De-molding Characterization Rheology XRD SEM Mechanical properties Thermal properties Leachability … Keywords Alumina ● Ceramic cores ● Sol–gel ● Tialite stabilization * Rahim Naghizadeh rnaghizadeh@iust.ac.ir 1 School of Metallurgy and Materials Engineering, Iran University of Science & Technology (IUST), Narmak, Tehran, Iran 1234567890();,: 1234567890();,: