Effect of Kaolin Grain Size on Firing Process and Physical Properties of Cordierite Ceramics

Nakahara, Masae; Kondo, Yoshinori; Hamano, Kenya

doi:10.2109/jcersj.106.787

Cited by 5 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Notably, Si 4+ diffuses slowly due to the strong Si‐O bond 19 . Japanese researchers have detected an element concentration gradient resulting from the diffusion of Mg 2+ and Al 3+ on the interface of talc and cordierite 26–28 . Similarly, there are Mg 2+ and Al 3+ concentration gradients on the interface of enstatite and Al 2 O 3 .…”

Section: Resultsmentioning

confidence: 99%

“…19 Japanese researchers have detected an element concentration gradient resulting from the diffusion of Mg 2+ and Al 3+ on the interface of talc and cordierite. [26][27][28] Similarly, there are Mg 2+ and Al 3+ concentration gradients on the interface of enstatite and Al 2 O 3 . Cordierite is formed by Al 3+ diffusing from corundum to enstatite, while spinel is produced by Mg 2+ diffusing from enstatite to Al 2 O 3 (Figure 4D).…”

Section: Xrd Analysismentioning

confidence: 99%

See 1 more Smart Citation

Formation, conversion, and elimination of intermediate spinel phase in MgO/kaolin mixture firing for cordierite

Yang,

Yan,

Cheng

et al. 2023

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

Cordierite ceramic is usually used for diesel particulate filter owing to its excellent low thermal expansion coefficient and high thermal shock resistance properties. However, the co‐exited intermediate spinel phase can deteriorate the thermal and mechanical performances of cordierite ceramic product, because the spinel phase has much higher thermal expansion coefficient comparing to that of cordierite. In this study, two methods are utilized to reduce the spinel impurity in the cordierite ceramic. On the one hand, rational reaction resources were introduced to decrease spinel production. The formation of intermediate spinel phase is systematically researched by X‐ray diffraction (XRD), scanning electron microscopy (SEM), Raman characterizations and the results clarified the preference of path “Enstatite + Mullite → Cordierite” for less spinel production in comparison to path “Enstatite + Al2O3 → Cordierite + Spinel.” Additionally, MgO was introduced as fluxing agent to promote liquid‐phase sintering, thus facilitating the conversion of spinel. On the other hand, the sintering schedule was improved by introducing a holding temperature gradient to promote the diffusion of Si4+ and further promote the conversion of spinel into cordierite. With these methods, the residual spinel phase is minimized, the resulting high‐purity cordierite has a 47% reduction in the thermal expansion coefficient from 3.07 × 10−6/K to 1.63 × 10−6/K compared to the original cordierite sample.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Xrd Analysismentioning

confidence: 99%

Formation, conversion, and elimination of intermediate spinel phase in MgO/kaolin mixture firing for cordierite

Yang,

Yan,

Cheng

et al. 2023

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

show abstract

“…Some researchers showed that the cordierite was formed together with spinel. 15,16 The temperature of the spinel formation ranges from 1050 • C to 1150 • C. 17,18 Because α-cordierite only develops at a temperature over 1200 • C, 17 the cordierite associated with spinel that occurs at a temperature between 1050 • C and 1150 • C should be the low-temperature phase β-cordierite.…”

Section: Introductionmentioning

confidence: 99%

Quasi‐synchronous solid‐state reaction for cordierite powder synthesis

Lin,

Yen,

Hsiang

et al. 2023

Int J Applied Ceramic Tech

View full text Add to dashboard Cite

This study investigates a quasi‐synchronous solid‐state reaction for synthesizing cordierite powder using talc, kaolinite, and Al2O3 mineral powders as starting materials. The thermal reaction proceeded with 2 different stages according to the Al sources provided by: (1) Al2O3 powders: the 1st stage starting at temperatures which are considerably lower than 1150°C and (2) kaolinite (mullite): 2nd stage starting at temperatures which are higher than 1150°C. The goal is to shift the temperature of the first stage to coincide with that of the second stage by mixing α‐cordierite powder with the starting constituents. Exceeding the authentic reduction amounts of Al2O3 on talc particles leads to a rise in the temperature required to initiate the first stage reaction to 1200°C. However, this also eliminates the presence of β‐cordierite and spinel that occur in the first stage and allows for the early fulfillment of α‐cordierite formation in the second stage. The excess SiO2 released by the second stage compensates for the insufficient SiO2 required by the first stage, allowing for a smooth processing reaction. Also, the quasi‐synchronous solid‐state reaction for synthesizing cordierite occurs.This article is protected by copyright. All rights reserved

show abstract