LAUSR

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 15 wt% 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 15 wt% titania and 4 wt% 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. MgO containing alumina-based ceramic cores were fabricated using non-toxic raw materials and without de-airing step by sol-gel method. Flexural strength, apparent porosity, leaching characteristics, and microstructural properties of the alumina cores were investigated. MgO was added to the precursor powders by different amounts of synthesized MgTi 2 O 5 powder and the optimum MgO content was investigated. Alumina core containing 4 wt% Magnesia exhibited minimum sintering shrinkage, apparent porosity of 30%, flexural strength of 40 MPa, thermal expansion coefficient of 4.3 × 10 −6  °C −1 and acceptable leaching properties.