Abstract: Aluminum magnesium dry ramming materials were prepared through heat treatment at 1 300 ℃,1 400 ℃,1 500 ℃ and 1 600 ℃ for 3 h,using fused white corundum,fused magnesia,reactive Al₂O₃ powder as main raw materials,and TiO₂ as clinkering aid.The effects of TiO₂ content,sintering temperature on the phase composition,sintering properties,mechanical properties and microstructures of aluminum magnesium dry ramming materials were investigated.The results show that the introduction of moderate amount of TiO₂ significantly promotes the reaction sintering of aluminum magnesium dry ramming materials,the mechanical properties both at normal and elevated temperatures are improved obviously.The strengthening of sintering performance is attributed to the formation of magnesium aluminum titanium phase and cation vacancy caused by the incorporation of TiO₂ into spinel lattice.Good comprehensive properties are obtained after heat treatment at 1 600 ℃ for 3 h when the TiO₂ content is 0.5%(mass fraction).At this time,the liner change rate is 3.7%,the bulk density and the porosity is 2.76 g·cm^-3 and 26.6 % respectively,the cold crushing strength is 18.9 MPa,and the HMOR is 1.9 MPa.When the content of TiO₂ is excessive,aluminate magnesium spinel materials show a large shrinkage as a result of excessive sintering,which is not conducive to the volume stability of the materials.

Key words: TiO₂, clinkering aid, induction furnace lining, aluminum magnesium spinel, dry ramming material, reaction sintering