JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Hongxing Zhan,Hailu Wang,Huayun Sun,Yuanbing Li,Shujing Li,Zhen Cai
Mullite-corundum ceramics with various mullite crystal structures were prepared by incorporating Fe 2 O 3 into the ceramic powder. The impact of the Fe 2 O 3 content on the morphological evolution and formation mechanism of mullite crystals, as well as the thermal shock resistance and enhancement mechanism of the ceramic, were investigated. The results show that Fe 2 O 3 facilitates the formation of a low-viscosity liquid phase and enhances the dissolution-precipitation mass transfer rate at the liquid/solid interface, forming an iron-containing mullite solid solution, inducing lattice distortion, and accelerating the c-axis growth of mullite crystals. With increasing Fe 2 O 3 content, the mullite crystals changed from short columnar to elongated structures, and the grains were gradually interwoven with each other to form a network structure. The intergranular fracture mode of the sample was transformed into a mixed mode of transgranular and intergranular fractures. The maximum flexural strength was 83.60 MPa, with a retention rate of 94.65%, indicating improved strength and thermal shock stability.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qian Ma,Anze Shui,Hulei Yu
The thermal shock behaviors of the multiple crack system based on aluminum titanate (Al 2 TiO 5 , AT) flexible ceramics are investigated. Two (fine/coarse-grained) systems are employed in this study to observe the influence of the grain size and microcrack size on the thermal shock behaviors of AT flexible ceramics. The findings reveal that these two systems exhibit markedly different adversarial strategies against high-temperature thermal shock. The coarse-grained system disperses the thermal stress by introducing new cracks and making stress evenly dispersed, while the fine-grained one can only concentrate thermal stress on limited microcracks. This is because almost all the grain boundaries in the coarse-grained system could serve as crack source sites, while that was only approximately 1/3 in the fine-grained one. Consequently, as the thermal shock temperature increases, the strain of the coarse-grained system first increases and then decreases, while its strength shows double peaks and double valleys. As for the fine-grained one, the strain decreases with the temperature increase, while its strength first increases and then decreases. Therefore, it can be concluded that the mechanical properties of AT flexible ceramics are closely related to microcracks' size and stress state. And, the conclusion that there exists a favorable state of internal stress and a favorable influence of microcracks that is beneficial to the mechanical performance of AT flexible ceramics could be drawn.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Fengrui Zhai,Shuang Li,Jialin Sun,Zhongzhou Yi
h -BN-SiC ceramic composites with different SiC contents were fabricated by spark plasma sintering . The results indicate that the addition of hard SiC particles has a remarkable effect on the densification, microstructure, mechanical properties and thermal shock resistance of the composites. Compared with pure h -BN ceramic, the relative density and mechanical properties of h -BN-SiC ceramic composites were improved obviously. The optimal properties of h -BN-SiC ceramic composites were obtained at SiC content of 25%, and the relative density, flexural strength and fracture toughness reached 97.8%, 289.2 MPa and 3.45 MPa m 1/2 , respectively. Moreover, the relationship of fracture toughness and fracture mode was discussed. The thermal shock test results showed that the h -BN-SiC ceramic composite with the SiC content of 25% exhibited excellent thermal shock resistance, presenting critical temperature difference up to 900 °C. The high temperature oxidation of h -BN and SiC on material surface led to the formation of borosilicate glass phase, which could heal the surface microcracks and then improve the thermal shock resistance.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Yongqiang Chen,Mao Chen,Beibei Tang,Guoqi Liu,Hongxia Li,Hailong Wang,Bingbing Fan
A uniform, dense, and well-bonded mullite/Y 2 Si 2 O 7 /ZrO 2 (MYZ) composite barrier coating was synthesized using a spraying technique followed by a two-step sintering process. The microstructure, phase composition, and thermal shock resistance of the MYZ coating were systematically investigated. The sintering process comprised two stages. In the initial stage (25–1350°C), granular mullite grains transformed into columnar crystals with progressive growth. Concurrently, a eutectic composite of mullite and Y 2 Si 2 O 7 formed and dispersed within the grain boundaries, significantly enhancing the coating's density and adhesion. In the subsequent stage (∼1400°C), ZrO 2 reacted with the eutectic composite to produce yttria-stabilized zirconia (YSZ) in situ. The YSZ phase exhibited excellent interfacial compatibility with the substrate, markedly improving the coating's high-temperature stability. As a result, the coating achieved high hardness and a coefficient of thermal expansion matching that of the SiC substrate. Remarkably, the MYZ coating withstood 20 thermal cycles between 25°C and 1200°C without noticeable interfacial damage.
研究领域:
材料科学
·
高温材料
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涂层技术
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Ceramic Engineering and Science
·
2020
·Vol. 2
·期 2
·101-109
·
IF 0
Anzhe Wang,Hailong Liao,Tao Zhang,Minqi Jiang,Fuxiao Guo,Yongzheng Wang
Reliable evaluation of the thermal shock behavior of sharp leading edges (SLEs) was hampered by a lack of available experimental method in past decades. Herein, a novel water spraying method was utilized to investigate the shape effect of ZrB 2 -SiC-Graphite SLEs during thermal shock. Experimental results indicated that the critical failure temperature of ZrB 2 -SiC-Graphite SLEs was most sensitive to the wedge angle, which could lead to a dramatic attenuation by about 35% from 12° to 9°, and was relatively little affected by the tip radius of curvature and the thickness. Simulation results further revealed that the decay of critical failure temperature was mainly due to the significant stress concentration caused by the reduction of wedge angle. Scanning electron microscopy observation proved that cracks tend to bypass graphite flakes due to their weak interfacial bonding, while branching always occurred when encountering hard phases or inclusions.
研究领域:
材料科学
·
热力学
·
结构力学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）