Effects of Al—Si addition on hot modulus of rupture （HMOR）,thermal shock resistance < TSR),phase composition and microstructure of low-carbon MgO - C materials were investigated.The results show that:Al and Si addition to low-carbon MgO - C materials leads to dramatic increase in MOR at elevated temperatures:it increases from 4 MPa to 11 -21 MPa at 1 200℃and from 2 MPa to 21 -29 MPa at 1 400℃.Al and Si addition to low-carbon MgO - C materials also improves TSR-.residual strength ratio after thermal shock when AT = 1 200℃is increased from 44%to 73%-77%. Al reacts with C and N2 to form Al4C3 and AlN:Si reacts with C to form SiC.Ultimately,in-situ formed nonoxides increase appreciably with temperature rising and are well interlaced in periclase skeleton structure at 1 300 -1 400℃.which is beneficial to thermomechanical properties.
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