Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as b...Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition increasing, the bulk density of the specimen treated at 220℃ tends to decrease and the apparent porosity increases, the strength of the specimens treated at 1100℃ and 1450℃ increases markedly, the bulk density tends to increase, apparent porosity and linear shrinkage decrease. The HMOR at 1400℃ is enhanced from 1.0 MPa to 3.5 MPa with 3% aluminium. Aluminium is served as sintering agent and anti-oxidant and it will react with CO and CO2 forming Al2O3 , which is helpful to enhance the strength, densify the structure and improve the overall properties.展开更多
Al2O3-SiC-C castables for iron trough with fused magnesia powder （0, 3%, 6%, 9% and 12%） were prepared with brown fused corundum particles （5-3mm, 3-1mm, ≤1mm）, white fused corundum powder （≤0.088mm）, SiC part...Al2O3-SiC-C castables for iron trough with fused magnesia powder （0, 3%, 6%, 9% and 12%） were prepared with brown fused corundum particles （5-3mm, 3-1mm, ≤1mm）, white fused corundum powder （≤0.088mm）, SiC particle （≤1mm） and powder （ ≤0.088mm）, fused magnesia powder （ ≤0. 088mm）, reactive α-Al2O3 micropowder, ultrafine SiO2 , Si powder and sphere pitch as main starting materials and calcium aluminate cement as binder. The specimens were fired at 1100℃ and 1450℃ for 3 h after vibrating moulding, curing, demoulding and drying at 110℃ for 24 h. Bulk density, apparent porosity, linear change rate, modulus of rupture, resistance to blast furnace slag, oxidation resistance, phase composition and microstructure of the specimens were analyzed. The results show that： （1） With fused magnesia addition increasing, apparent porosity increases, while bulk density, modulus of rupture and oxidation resistance decline, slag resistance varies slightly; （2） The main crystal phases in the specimens fired at 1450℃ for 3 h are 3C-SiC, 6H-SiC, corundum, periclase, reaction-synthesized spinel and mullite; the quantity of the formed spinel and mullite increases with the increase of fuzed magnesite addition; （3） Along the corroded side, spinel layer with about 80μm thickness forms at the co- rundum particles boundary.展开更多
文摘Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition increasing, the bulk density of the specimen treated at 220℃ tends to decrease and the apparent porosity increases, the strength of the specimens treated at 1100℃ and 1450℃ increases markedly, the bulk density tends to increase, apparent porosity and linear shrinkage decrease. The HMOR at 1400℃ is enhanced from 1.0 MPa to 3.5 MPa with 3% aluminium. Aluminium is served as sintering agent and anti-oxidant and it will react with CO and CO2 forming Al2O3 , which is helpful to enhance the strength, densify the structure and improve the overall properties.
文摘Al2O3-SiC-C castables for iron trough with fused magnesia powder （0, 3%, 6%, 9% and 12%） were prepared with brown fused corundum particles （5-3mm, 3-1mm, ≤1mm）, white fused corundum powder （≤0.088mm）, SiC particle （≤1mm） and powder （ ≤0.088mm）, fused magnesia powder （ ≤0. 088mm）, reactive α-Al2O3 micropowder, ultrafine SiO2 , Si powder and sphere pitch as main starting materials and calcium aluminate cement as binder. The specimens were fired at 1100℃ and 1450℃ for 3 h after vibrating moulding, curing, demoulding and drying at 110℃ for 24 h. Bulk density, apparent porosity, linear change rate, modulus of rupture, resistance to blast furnace slag, oxidation resistance, phase composition and microstructure of the specimens were analyzed. The results show that： （1） With fused magnesia addition increasing, apparent porosity increases, while bulk density, modulus of rupture and oxidation resistance decline, slag resistance varies slightly; （2） The main crystal phases in the specimens fired at 1450℃ for 3 h are 3C-SiC, 6H-SiC, corundum, periclase, reaction-synthesized spinel and mullite; the quantity of the formed spinel and mullite increases with the increase of fuzed magnesite addition; （3） Along the corroded side, spinel layer with about 80μm thickness forms at the co- rundum particles boundary.
