Amino-functionalization of colloidal alumina particles for enhancement of the infiltration behavior in a silica-based ceramic core

An, Gye Seok; Choi, Soo Wan; Kim, Tae Kyun; Shin, Jae Rok; Kim, Yong In; Choi, Sung Churl; Jung, Young Gil

doi:10.1016/j.ceramint.2016.09.127

Cited by 23 publications

(7 citation statements)

References 17 publications

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“…Crystallization has a complicated effect on the properties of silica‐based ceramic cores. It has been reported that the mechanical properties of silica‐based ceramic cores can be reduced when the sintered samples with too much or too little cristobalite formation . Since cristobalite has a higher strength than fused silica, the ceramic cores with a small quantity of cristobalite show poor flexural strength.…”

Section: Introductionmentioning

confidence: 99%

Silica‐based ceramic core for aviation applications: Facile pore filling and flexural strength improvement

Chen

Han

Zhang

et al. 2019

Int J Applied Ceramic Tech

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The effect of alumina addition on the pore filling process, crystallization behavior and mechanical properties of silica-based ceramic cores was investigated. The sintered samples at 1250°C were treated at 1550°C for 0.5 hour in order to simulate a casting process condition. The microstructure analysis indicated that an appropriate alumina addition enhanced the pore filling process by supplying a substantial liquid viscous flow. With an increase in the liquid viscous flow, smaller pores were filled first, and larger pores were filled later. The results also indicated that the pore filling process could be enhanced by adding small powder additives to decrease the pore size between the particles in the ceramic material. However, an excessive alumina addition in the silica-based ceramic cores had a negative effect on the flexural strength and leaching rate. As the alumina content increased from 8 to 12 wt%, the flexural strength of the ceramic core decreased from 16.37 to 4.60 MPa, respectively, and the leaching rate also decreased obviously. These results were explained by an acceleration in crystallization trend of the fused silica particle surface and the merging of connected pores in the sintered body. K E Y W O R D Sliquid viscous flow, mechanical properties, pore filling process, silica-based ceramic core 2182 | CHEN Et al.

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Section: Introductionmentioning

confidence: 99%

Silica‐based ceramic core for aviation applications: Facile pore filling and flexural strength improvement

Chen

Han

Zhang

et al. 2019

Int J Applied Ceramic Tech

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“…This result suggests that surface stabilization with PVA and Neem had reduced agglomeration of coupled oxides. This improvement in particle dispersion occurred due to the long and branched alkyl chains that induced substantial steric hindrance to repel the particles [31,32]. Furthermore, Smith et al reported that zeta potential does not have a significant effect on repulsive electrostatic interaction to stabilize catalysts in nonpolar solvent.…”

Section: Stability and Compatibility Test Of The 3zt-co Particlesmentioning

confidence: 99%

“…A bulky ligand often leads to higher stability of the nanoparticle-ligand system [34]. alkyl chains that induced substantial steric hindrance to repel the particles [31,32]. Furthermore, Smith et al reported that zeta potential does not have a significant effect on repulsive electrostatic interaction to stabilize catalysts in nonpolar solvent.…”

Section: Stability and Compatibility Test Of The 3zt-co Particlesmentioning

confidence: 99%

Coupled Oxides/LLDPE Composites for Textile Effluent Treatment: Effect of Neem and PVA Stabilization

et al. 2020

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The polyvinyl alcohol (PVA) and neem extract were grafted onto coupled oxides (3ZT-CO) via reflux process to stabilize the particles to form 3ZT-CO/PVA and 3ZT-CO/Neem. These were then incorporated into LLDPE by melt blending process to give LLDPE/3ZT-CO/PVA and LLDPE/3ZT-CO/Neem composites. The Neem and PVA stabilized particles showed high zeta potential and dispersed homogeneously in water. The stabilization process altered the shape of the particles due to plane growth along the (002) polar direction. The stabilizers acted as capping agents and initiated the one-dimensional growth. The alkyl chain groups from PVA increased the polarity of the LLDPE/3ZT-CO/PVA and played a dominant role in the water adsorption process to activate the photocatalytic activity. This was further enhanced by the homogeneous distribution of the particles and low degree of crystallinity (20.87%) of the LLDPE composites. LLDPE/3ZT-CO/PVA exhibited the highest photodegradation (93.95%), which was better than the non-stabilized particles. Therefore, the photocatalytic activity of a polymer composite can be enhanced by grafting PVA and neem onto couple oxides. The LLDPE/3ZT-CO/PVA composite was further used to treat textile effluent. The results showed the composite was able to remove dye color by 93.95% and to reduce biochemical oxygen demand (BOD) and chemical oxygen demand (COD) by 99.99%.

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“…Because the ceramic cores should be removed, its open porosity should be greater than 30%. During the preparation of hollow turbine blades, the ceramic cores should be able to withstand a certain amount of impact; therefore, its flexural strength should be greater than 20 MPa [14][15][16][17][18][19].…”

Section: Introduction mentioning

confidence: 99%

Effect of sintering temperature in argon atmosphere on microstructure and properties of 3D printed alumina ceramic cores

et al. 2020

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Alumina ceramics with different sintering temperatures in argon atmosphere were obtained using stereolithography-based 3D printing. The effects of sintering temperature on microstructure and physical and mechanical properties were investigated. The results show that the average particle size, shrinkage, bulk density, crystallite size, flexural strength, Vickers hardness, and nanoindentation hardness increased with the increase in sintering temperature, whereas the open porosity decreased with increasing sintering temperature. No change was observed in phase composition, chemical bond, atomic ratio, and surface roughness. For the sintered samples, the shrinkage in Z direction is much greater than that in X or Y direction. The optimum sintering temperature in argon atmosphere is 1350 ℃ with a shrinkage of 3.0%, 3.2%, and 5.5% in X, Y, and Z directions, respectively, flexural strength of 26.7 MPa, Vickers hardness of 198.5 HV, nanoindentation hardness of 33.1 GPa, bulk density of 2.5 g/cm 3 , and open porosity of 33.8%. The optimum sintering temperature was 70 ℃ higher than that sintering in air atmosphere when achieved the similar properties.

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Amino-functionalization of colloidal alumina particles for enhancement of the infiltration behavior in a silica-based ceramic core

Cited by 23 publications

References 17 publications

Silica‐based ceramic core for aviation applications: Facile pore filling and flexural strength improvement

Silica‐based ceramic core for aviation applications: Facile pore filling and flexural strength improvement

Coupled Oxides/LLDPE Composites for Textile Effluent Treatment: Effect of Neem and PVA Stabilization

Effect of sintering temperature in argon atmosphere on microstructure and properties of 3D printed alumina ceramic cores

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