scholarly journals Improving self-healing ability and flexural strength of ytterbium silicate-based nanocomposites with silicon carbide nanoparticulates and whiskers

2021 ◽  
Vol 129 (4) ◽  
pp. 209-216
Author(s):  
Son Thanh NGUYEN ◽  
Tsuyoshi TAKAHASHI ◽  
Ayahisa OKAWA ◽  
Hisayuki SUEMATSU ◽  
Koichi NIIHARA ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Flexural Strength ◽  
Self Healing ◽  
Ytterbium Silicate

scholarly journals Simultaneous effects of rice husk silica and silicon carbide whiskers on the mechanical properties and morphology of sodium geopolymer

2020 ◽  
Vol 54 (29) ◽  
pp. 4611-4620 ◽  
Author(s):  
Akm Samsur Rahman ◽  
Chirag Shah ◽  
Nikhil Gupta
Keyword(s):  
Silicon Carbide ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Silica Nanoparticles ◽  
Rice Husk ◽  
Silicon Carbide Whiskers ◽  
Short Beam ◽  
Spherical Silica ◽  
Beam Shear ◽  
Strength Improvement

The current research is focused on developing a geopolymer binder using rice husk ash–derived silica nanoparticles. Four types of rice husks were collected directly from various rice fields of Bangladesh in order to evaluate the pozzolanic activity and compatibility of the derived rice husk ashes with precursors of sodium-based geopolymers. Silicon carbide whiskers were introduced into sodium-based geopolymers in order to evaluate the response of silicon carbide whiskers to the interfacial bonding and strength of sodium-based geopolymers along with rice husk ashes. Compression, flexural and short beam shear tests were performed to investigate the synergistic effect of rice husk ashes–derived silica and commercially available silicon carbide whiskers. Results show that rice husk ashes–derived spherical silica nanoparticles reduced nano-porosity of the geopolymers by ∼20% and doubled the compressive strength. The simultaneous additions of rice husk ashes and silicon carbide whiskers resulted in flexural strength improvement by ∼27% and ∼97%, respectively. The increase in compressive strength due to the inclusion of silica nanoparticles is related to the reduction in porosity. The increase in flexural strength due to simultaneous inclusion of silica and silicon carbide whiskers suggest that silica particles are compatible with the metakaolin-based geopolymers, which is effective in consolidation. Finally, microscopy suggest that silicon carbide whiskers are effective in increasing bridged network and crack resistance.

scholarly journals Self-Healing of SiC-Al2O3-B4C Ceramic Composites at Low Temperatures

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 652
Author(s):  
Baoguo Wang ◽  
Rong Tu ◽  
Yinglong Wei ◽  
Haopeng Cai
Keyword(s):  
Flexural Strength ◽  
Low Temperatures ◽  
Ceramic Composite ◽  
Ceramic Composites ◽  
Self Healing ◽  
Vickers Indentation ◽  
Crack Healing ◽  
Practical Applications ◽  
Plasma Sintering ◽  
Spark Plasma

Self-healing ceramics have been researched at high temperatures, but few have been considered at lower temperatures. In this study, SiC-Al2O3-B4C ceramic composite was compacted by spark plasma sintering (SPS). A Vickers indentation was introduced, and the cracks were healed between 600 °C and 800 °C in air. Cracks could be healed completely in air above 700 °C. The ceramic composite had the best healing performance at 700 °C for 30 min, recovering flexural strength of up to 94.2% of the original. Good crack-healing ability would make this composite highly useful as it could heal defects and flaws autonomously in practical applications. The healing mechanism was also proposed to be the result of the oxidation of B4C.

Microporous Ceramics Made by Silicon Carbide Whiskers

2007 ◽  
Vol 336-338 ◽  
pp. 1904-1905
Author(s):  
Chang Hong Dai ◽  
Ru Zhao ◽  
Li Shui ◽  
Bao Bao Zhang
Keyword(s):  
Silicon Carbide ◽  
Flexural Strength ◽  
Pore Size ◽  
Sintering Temperature ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Sintering Aids ◽  
Silicon Carbide Whiskers ◽  
Physical And Chemical ◽  
And Chemical Properties

A new method for preparing microporous ceramics by the silicon carbide whiskers was studied in this paper. The physical and chemical properties and the microstructure of the microporous ceramics were tested, while some influencing factors for the product, such as the amount of sintering aids and sintering temperature, were discussed. The results suggest that the apparent porosity of the microporous ceramics is 55.7-59.8% and the flexural strength is 127-176MPa. The pore distribution of the microporous ceramics is uniformity and the diameter of the pore ranges between 0.5μm and 7μm. The porosity and pore size of the microporous ceramic can be controlled by adjusting the sintering temperature and the amount of sintering aids.

Effect of Gel Chemistry on the Machinability of Green SiC Parts Produced by Gelcasting

2012 ◽  
Vol 727-728 ◽  
pp. 1596-1603
Author(s):  
André Marques Riviello ◽  
Fernando dos Santos Ortega
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Statistical Analysis ◽  
Flexural Strength ◽  
Cutting Force ◽  
Complex Geometry ◽  
Automotive Components ◽  
Green Machining ◽  
Gelcasting Process

The growing interesting in the use of silicon carbide in automotive components, biomaterials, energy, among others, which demand the production of parts with complex geometry that are difficult to obtain by conventional compaction techniques, motivates the search for developing new conformation processes. Within this context, this paper investigates the production of pieces of silicon carbide through the gelcasting process and subsequent green machining of these parts. Three systems of monomers were studied: MAM-NVP-MBAM, MAM-PEG (DMA) and MAM-HMAM. The effect of the concentration of monomers, concentration of chemical initiator and the ratio of chain-forming and crosslinker monomers on the cutting force during machining and surface roughness were evaluated. These data are compared with values of flexural strength and hardness of samples produced under the same conditions. Through a statistical analysis it was determined the best formulation for the production of parts of SiC with favorable characteristics of green machining.

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