Preparation of in-situ Ti3Si(Al)C2 reaction bonded low carbon Al2O3–C refractories and its abnormal thermal shock behavior

In view of the requirements of low carbon and guaranteed service performance of functional refractories in the steel continuous casting process, in-situ Ti3Si(Al)C2 reaction bonded low carbon Al2O3–C refractories were prepared by reactive melt infiltration (RMI). The microstructure, mechanical properties, especially the thermal shock resistance of obtained refractories were investigated. The results showed that Ti3Si(Al)C2 in-situ formed in Al2O3–C refractories, leading to refractories comparable or superior mechanical properties compared to commercial ones. With the increase of infiltration temperature from 1450 °C to 1550 °C, the amount of Ti3Si(Al)C2 increased and the cold modulus of rupture (CMOR) of obtained refractories was enhanced. Particularly, the increased CMOR from 49.9 MPa to 62.7 MPa before and after thermal shock indicated its excellent thermal shock resistance. This abnormal phenomenon can be attributed to the inherent properties of Ti3Si(Al)C2. Meanwhile, it may be also related to the crack healing behavior in obtained refractories at high temperatures.