Strong and tough Al2O3–MgO–C refractories with dispersed aluminosilicate reinforcement

Abstract

Resin–bonded Al2O3–MgO–C refractories were fabricated with dispersed aluminosilicate reinforcement. The reinforced systems were strong and tough to thermal shock failures over the standard components without reinforcement. MOR measurements showed that the shocked refractories with reinforcement were failed with a maximum strength of 20 MPa, indicating 200% increase of their load bearing capacity. Toughness and fracture surface energy improvements predicted that the shocked systems reinforced with aluminosilicate particulates exhibit three times enhanced resistance to mutual crack growth over the standard. All these beneficial properties indicate a satisfactory thermal shock performance, which is credited to the effective operation of dispersion strengthening\\viscoelastic bridging effects offered by a flaw–tolerant microstructure formed in all parts of the refractory oxidized layer fortified with dispersed aluminosilicate reinforcement. Additionally, implications of these results to microstructure design of various classes of carbon containing refractories in MgO–C\\Al2O3–C systems formulated with carbon\\ceramic reinforcements are proposed.