Effects of Al-Si Addition on Thermomechanical Properties of Low Carbon MgO-C Materials

摘要

The 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 have been investigated.The results show that with the addition of Al-Si (1)HMOR increases dramatically,e.g.at 1400°C,it increases from 2 MPa to 20-29 MPa; (2)Residual strength ratio after thermal shock (ΔT=1200°C,air cooling 3 cycles) increases from 44％ to 73-77％.Al reacts with C and N2 to form Al4C3 and AlN; Si reacts with C to form SiC.Ultimately amount of in situ formed nonoxides increases appreciably with temperature rise and at 1300-1400°C they are well interlaced in periclase skeleton structure which would be beneficial to thermomechanical properties.