The critical role of aggregate microstructure in thermal shock resistance and slag resistance of Al2O3–SiC–C castable

Ma, Jun; Zhao, Huizhong; Yu, Jun; Zhang, Han; Li, Yichong; Shi, Lida; Zhao, Yufan; He, Jun

doi:10.1016/j.ceramint.2022.01.022

Cited by 12 publications

(4 citation statements)

References 20 publications

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“…When the temperature difference is ΔT=450 ℃, the residual strength decreases to 1/3 of the initial strength. Ma [36] studied the thermal shock resistance of Al2O3-SiC-C refractory material by heating the sample to 1100 ℃ and water-cooled for 5 times, and the strength retention rate was less than 52%. In comparison, the high strength retention rate in this work indicates that the sample has good thermal shock stability, which can improve the service life of the crucible to withstand the temperature difference between high-temperature alloy melting and casting.…”

Section: Thermal Shock Resistancementioning

confidence: 99%

Alumina-based crucibles with enhanced thermal shock resistance via reinforcement of mullite fibers

2023

jmpd

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Crucible is the indispensable vessel in smelting of superalloy, and the service life of crucibles is quite important to the development of superalloy. In order to extend the service life of crucible for superalloy smelting, alumina-based crucibles are prepared by slip casting, and mullite fibers are used as reinforcement phase. The effect of mullite fibers on the microstructure and property of the crucibles was studied. The appropriate content of mullite fibers are beneficial to the comprehensive performance of the crucibles. The reinforcement mechanism of mullite fibers includes crack deflection, fiber extraction, and fiber bridging, through which fibers hinder the initiation and propagation of cracks in ceramics. For the crucible samples with 3 wt% of mullite fibers, the values of flexure strength are 22.47 MPa and 19.14 MPa at room temperature and high-temperature, respectively. After thermal shock for 5 times, the residual room-temperature flexural strength is 16.65 MPa and the strength retention rate is 74.1%. It is confirmed that, the 3 wt% of mullite fibers improves the thermal shock resistance of the crucible, which is beneficial for extending the service life of the crucible for superalloy melting.

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Section: Thermal Shock Resistancementioning

confidence: 99%

Alumina-based crucibles with enhanced thermal shock resistance via reinforcement of mullite fibers

2023

jmpd

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“…Chen et al 19 selected lightweight alumina aggregates to partially replace traditional tabular alumina aggregates to prepare lightweight Al 2 O 3 -MgO-C refractories, which improved the strength, thermal shock resistance, and slag corrosion resistance of the material. Ma et al 20 found that tabular corundum aggregates with dendritic pore microstructure were more conducive to improving the corrosion resistance of Al 2 O 3 -SiC-C castables.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and densification mechanism of tabular corundum aggregates: Role of molding methods

Yu,

Han,

Wei

et al. 2024

Int J Applied Ceramic Tech

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In this paper, tabular corundum aggregates were prepared using the rolling ball method and semi‐dry pressing combined with the cold isostatic pressing method, using industrial alumina raw powder as the raw material and water as the binder, respectively. Then, the influence of various molding methods on phase composition, microstructure, pore characteristics, densification, and physical properties was investigated by X‐ray diffraction, scanning electron microscopy, and Archimedes’ principle. The results revealed that tabular corundum aggregates prepared using the rolling ball method had higher bulk density and lower apparent porosity. It also rendered a relatively homogeneous grain size distribution and a high cylinder compressive strength retention rate of 68.0%. The grain size distribution and pore size distribution of tabular corundum aggregates prepared using semi‐dry pressing combined with the cold isostatic pressing method were wide, and there were a few large pores, which decreased the strength and densification. Green density was a key factor influencing the sintering; the two molding methods minimized porosity and improved the green density through collision extrusion and external force, respectively. Meanwhile, the molding process also increased the contact points between particles and the material migration channels, which had an impact on the densification mechanism of tabular corundum aggregates.

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“…It intends to greatly improve the safety of blast furnace hearth when smelting strength changes, and extend the blast furnace campaign. The higher the thermal conductivity, the faster the heat transfer when the hearth lining has a large temperature change, the smaller the temperature gradient inside the hearth lining refractory, the stronger the resistance to thermal stress, the longer the service life of the refractory, and the more extensive of the blast furnace campaign [16]. Therefore, the detection of the thermal conductivity of alumina-carbon composite bricks is of great practical significance.…”

Section: Introductionmentioning

confidence: 99%

Thermal conductivity of alumina-carbon composite brick and its related phase analysis in a dissected blast furnace

Wang

Cao

Zhang

et al. 2023

Metall. Res. Technol.

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Excellent performance of refractories in blast furnace hearth is one of the important factors to ensure longevity of blast furnaces. As an emerging refractory for application in blast furnace, alumina-carbon composite brick combines the superior properties of carbon and alumina. Firstly, the thermal conductivity of alumina-carbon composite brick was measured by the laser flash method and the new device method to verify the feasibility of the new device method for thermal conductivity measurement. Secondly, the influence of heating temperature of the heating furnace and cooling water flow on the thermal conductivity of the alumina-carbon composite brick, and the comparison of the thermal conductivity of carbon brick, alumina-carbon composite brick and corundum brick were investigated to confirm the heat transfer mechanism of alumina-carbon composite brick. High thermal conductivity and erosion resistance to slag and hot metal of the alumina-carbon composite brick are consequent from: (a) reasonable composition combination of Al2O3, C, SiO2, SiC, etc., (b) dense structure, small pore diameter, and uniform distribution of the pores, (c) the generated SiC whiskers and Al6Si2O13, which can fill in the pores and reduce the porosity. Finally, the analysis on the phase distribution of the alumina-carbon composite brick in a dissected blast furnace was performed to illustrate the relationship between the erosion resistance and the thermal conductivity of alumina-carbon composite brick.

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The critical role of aggregate microstructure in thermal shock resistance and slag resistance of Al2O3–SiC–C castable

Cited by 12 publications

References 20 publications

Alumina-based crucibles with enhanced thermal shock resistance via reinforcement of mullite fibers

Alumina-based crucibles with enhanced thermal shock resistance via reinforcement of mullite fibers

Microstructure and densification mechanism of tabular corundum aggregates: Role of molding methods

Thermal conductivity of alumina-carbon composite brick and its related phase analysis in a dissected blast furnace

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