Materials
·
2022
·Vol. 15
·期 3
·793
·
IF 3.748
Hai Tang,Yuhao Zhou,Wenjie Yuan
To investigate the action mechanism of titanium, the effects of different Ti-bearing compounds, including CaTiO3, MgTiO3, and nano-TiO2, on the properties of alumina–magnesia castables were studied. By analyzing the phase compositions, microstructures, and physical and mechanical properties of the castables, it was demonstrated that an intermediate product, CaTiO3, was first generated. This was then consumed by solid-solution reactions, and titanium was involved in the liquid formation as the temperature increased. The solid-solution reaction of CA6(CaAl12O19) was more prominent due to the incorporation of more titanium in the crystal lattice of CA6instead of spinel (MgAl2O4). Moreover, the liquid formation was strongly promoted when more titanium accompanied the calcium, which finally accelerated the densification and improved the strengths of alumina–magnesia castables. On the whole, castables with CaTiO3addition presented higher bulk density and excellent strength after the heat treatment. Besides, the castables with 2 wt.% CaTiO3contents were estimated to possess greater thermal shock resistance.Keywords:Ti-bearing compounds;CA6;spinel;castables
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Yichong Li,Huizhong Zhao,Han Zhang,Jun Yu,Wei Wang,Jiulin Xu
Ferrotitanium slag (FTS) is the waste product that has gained attention as a potential calcium hexaaluminate (CA 6 ) resource in recent years. In this study, the phase distribution of FTS and CA 6 aggregate was compared, and its effect on the cryolite resistance of castables was further studied. Scanning electron microscopy and least-squares refinement program were used to characterize the phase distribution and crystallographic parameters of ferrotitanium slag. Computational and experimental results demonstrate that ferrotitanium slag contains denser and larger hibonite crystals compared to synthetic calcium hexaaluminate. Ti element exists in the hibonite crystal in the form of coupled substitution or direct substitution of Al 3+ . Performance evaluation in refractory castables also confirms the resulting improvement in corrosion resistance.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Mengke Qiao,Xiangcheng Li,Pingan Chen,Yingli Zhu,Boquan Zhu
The effect of nano-zirconia addition on the microstructure and properties of corundum castables was studied using corundum, kyanite, alumina powder, gel powder, and nano-ZrO 2 as raw materials. The results showed that adding 1.2(wt)% nano-ZrO 2 could reduce the median pore diameter of the castables from 480 to 200 nm at 110 °C. After the castables were heated at 1100 °C, the cold modulus of rupture increased by 29.95%, to 24.71 MPa, and the cold compressive strength increased by 50.32%, to 116.37 MPa. The hot modulus of rupture increased by 114.95%, to 3.59 MPa after being treatment at 1500 °C, the high surface energy of nano-ZrO 2 can increase the interface energy and bonding strength between adjacent particles.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yichong Li,Huizhong Zhao,Yang Yang,Zecheng Feng,Han Zhang,Jun Yu,Yanli Liu,Li Feng
Calcium alumino-titanate (CAT) is widely used as a refractory raw material in China. It is obtained by the recycling of non-ferrous metallurgical solid waste and is often used in high-temperature oxidizing environments. The main crystal phase of CAT is the Ca(Al,Ti) 12 O 19 , which is unstable under high temperature oxidizing environments and preferentially forms a new phase system. In this study, CAT raw materials were prefired in air to facilitate the reconstructing process from Ca(Al,Ti) 12 O 19 to CaAl 12 O 19 in air. Herein, the effects of the prefiring of CAT raw materials on the mechanical properties and thermal conductivity of tundish permanent lining castables were studied and mechanism of restructuring-sintering of CAT aggregates in this process was proposed based on it. The results showed that the use of prefired CAT raw materials reduced the bulk density and mechanical strength of the castable samples after baking at 110 °C for 24 h. After firing at 1400 °C for 3 h, these samples showed greater volume shrinkage and higher mechanical strength than those prepared using CAT raw materials. The use of prefired CAT raw materials reduced the formation of anorthite in the castable matrix, thereby reducing the pores formed by liquid–phase transfer in the matrix; however, it resulted in castables with higher thermal conductivity than those prepared using unfired CAT raw materials.
研究领域:
材料科学
·
冶金工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Chuang Jie,Hao Liu,Zhoufu Wang,Xitang Wang,Yan Ma
To improve the energy-saving capacity of magnesia refractory castables for working lining of high-temperature kilns, this study presents the researches on microstructure and properties of lightweight magnesia refractory castables with porous matrix fabricated by direct foaming method. The results show that formation of closed-pores in the matrix significantly enhanced high-temperature thermal insulation performance of castables with minor changes of slag corrosion resistance . The thermal conductivity of the lightweight magnesia castables at 1000 °C was below 1.2 W/m·K, which is 47.8% lower than that of the referenced magnesia castable. The increasing content of SDS (foaming agent, over 0.02 wt%) led to increments of size and number of large-sized pores, resulting in the significantly decreased density and mechanical performances. The slag resistance mechanism reveals that, in addition to intergranular penetration, the accumulation of slag and penetration between adjacent pores were the major ways of slag mass transfer in lightweight magnesia castables. In conclusion, controlling the size (below 53.2 μm), number and distribution of closed-pores in the matrix is effective to realize the coupling of high thermal insulation, mechanical properties and slag resistance for lightweight magnesia castables used in the metallurgical field.
研究领域:
材料科学
·
耐火材料
·
无机非金属材料
·
高温工程材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）