Reaction Formed SiC Prepared by Room Temperature Freezing Casting

2012 ◽  
Vol 512-515 ◽  
pp. 297-300
Author(s):  
Chuan Qi Hu ◽  
Hua Wang ◽  
Hai Lin Liu ◽  
Yan Li Huo ◽  
Jie Tang ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Silicon Carbide ◽  
Flexural Strength ◽  
Porous Carbon ◽  
Weibull Modulus ◽  
Room Temperature ◽  
Methyl Cellulose ◽  
Infiltration Process ◽  
Carbon Preform ◽  
Carbon Resource

The porous carbon preforms with fine pore structure has been successfully fabricated by room temperature freezing casting, and the reaction formed SiC with fine mechanical property has prepared successfully by liquid silicon infiltration process. Charcoal powder was used as carbon resource, camphene was used as sublimate vehicle, methyl cellulose was used as pore maker and bonder. The result shows that the homogeneity of the porous carbon preform has been improved largely by adding methyl cellulose ,and the defects of reaction formed silicon carbide has reduced largely also. The density, average flexural strength and Weibull modulus of the best reaction formed silicon carbide prepared in this paper is 2.86 g/cm3, 430.75MPa and 9.29 respectively.

Young’s Modulus and Poisson’s Ratio of Liquid Phase-Sintered Silicon Carbide

2011 ◽  
Vol 484 ◽  
pp. 98-101
Author(s):  
Yasushi Okuzono ◽  
Yoshihiro Hirata ◽  
Naoki Matsunaga ◽  
Soichiro Sameshima
Keyword(s):  
Flexural Strength ◽  
Young’S Modulus ◽  
Compressive Stress ◽  
Poisson’S Ratio ◽  
Weibull Modulus ◽  
Room Temperature ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Stress Strain Relation ◽  
Sintered Silicon

The compressive stress-strain relation (room temperature) of SiC compact (75 vol% 800 nm SiC- 25 vol% 30 nm SiC) hot-pressed with 1.6 vol% Al2O3- 0.83 vol% Gd2O3 at 1950 °C was examined at a crosshead speed of 0.05 mm/min. The dense SiC (97.8 ± 1.5 % theoretical density) possessed 796 MPa of average flexural strength, 5.27 MPa・m1/2 of fracture toughness, 8.1 of Weibull modulus, and 475 GPa of average flexural Young’s modulus. The strains of SiC compacts along directions of height and width changed nonlinearly with applied compressive stress. The apparent Young’s modulus and Poisson’s ratio decreased with increasing strain along the direction of height and reached constant values of 275 ± 59 GPa and 0.214 ± 0.05, respectively. The steady-state compressive Young’s modulus was independent of the flexural strength.

scholarly journals Evaluasi Pembuatan Prototype Package Tray Biokomposit Serat Tebu- Polypropylene untuk Kebutuhan Interior Mobil

2020 ◽  
Vol 17 (2) ◽  
pp. 42-47
Author(s):  
Patrik Permana Putra Wijaya ◽  
Juliana Anggono
Keyword(s):  
Mechanical Property ◽  
Flexural Strength ◽  
Sugarcane Bagasse ◽  
Room Temperature ◽  
Natural Fibers ◽  
Interfacial Region ◽  
Flexural Test ◽  
The Matrix ◽  
Naoh Solution ◽  
Strong Material

Natural fibers used in the fabrication of biocomposite product can support the need of the industries for lightweight yet strong material. Sugarcane bagasse is one of the available natural fibers in Indonesia. There have been some research done on these bagasse fibers as reinforcement materials for plastics and their incorporation to the matrix has improved its strength. This research aimed to evaluate the fabrication of a car package tray prototype. The composition and the bagasse were prepared in accordance with the previous research in which the bagasse were alkali treated using NaOH solution of 8 wt% for one hour at room temperature. The hotpressed prototype was evaluated by its physical outlook and the mechanical property of its preform. The flexural test shows a low flexural strength of the prototype (7.4 MPa) compared to the required strength of the current material (woodboard) used by the industry (35.58 MPa). The evaluation shows the clustering of bagasse fibers, uneven distribution of sugarcane/PP in the structure and low adhesion at the interfacial region between bagasse fibers and PP.

Reaction forming of silicon carbide ceramic using phenolic resin derived porous carbon preform

2009 ◽  
Vol 29 (11) ◽  
pp. 2395-2402 ◽  
Author(s):  
Shunjian Xu ◽  
Guanjun Qiao ◽  
Dichen Li ◽  
Hong Yang ◽  
Yinong Liu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Porous Carbon ◽  
Phenolic Resin ◽  
Carbon Preform ◽  
Silicon Carbide Ceramic

Fabrication and Properties of Porous Carbon Preforms for Making Reaction Formed SiC

2016 ◽  
Vol 697 ◽  
pp. 169-172
Author(s):  
Chuan Qi Hu ◽  
Xiao Ting Huang ◽  
Hai Long Liang ◽  
Shu Guang Chen ◽  
Yan Li Huo ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Pore Structure ◽  
Porous Carbon ◽  
Weibull Modulus ◽  
Low Cost ◽  
Vacuum Condition ◽  
Polymer Dispersant

This paper describes a proper low cost way to fabricate defects free porous carbon preforms with interconnect pore structure for making reaction formed SiC (RFSC). Taking charcoal , poplar powder, camphene and polymer dispersant together, making slurries by milling under 55 °C for several hours, controlling the content of charcoal and poplar powder, after casting, sublimating and carbonizing, the porous carbon performs with a series density (0.66 g/cm3-0.78 g/cm3) and porosity (62.9 vol.%-68.6 vol.%) were prepared; through the Si infiltrating process under a vacuum condition (~5.0 Pa) at 1500°C for about 0.5 hour, the RFSCs with fine mechanic performance were fabricated, one RFSC sample has the density, Weibull modulus, and the max three points flexural strength is 2.91 g/cm3, 9.5 and 505.0 MPa respectively.

scholarly journals NDE Reliability and Process Control for Structural Ceramics

1987 ◽  
Vol 109 (3) ◽  
pp. 263-266 ◽  
Author(s):  
G. Y. Baaklini
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Flexural Strength ◽  
Process Control ◽  
Room Temperature ◽  
Acoustic Microscopy ◽  
Modulus Of Rupture ◽  
Scanning Laser ◽  
Radiographic Evaluation ◽  
Structural Ceramics

The reliability of microfocus x-radiography and scanning laser acoustic microscopy for detecting microvoids in silicon nitride and silicon carbide was statistically evaluated. Materials and process-related parameters that influenced the statistical findings in research samples are discussed. The use of conventional x-radiography in controlling and optimizing the processing and sintering of an Si3N4-SiO2-Y2O3 composition designated NASA 6Y is described. Radiographic evaluation and guidance helped develop uniform high-density Si3N4 modulus-of-rupture bars with improved four-point flexural strength (857, 544, and 462 MPa at room temperature, 1200°C, and 1370°C, respectively) and reduced strength scatter.

scholarly journals Biomorphic Silicon Carbide from Malaysian Hardwood

2018 ◽  
Vol 7 (4.26) ◽  
pp. 257
Author(s):  
Noor Leha Abdul Rahman ◽  
Koay Mei Hyie ◽  
Anizah Kalam ◽  
Fauziah Md Yusof
Keyword(s):  
Silicon Carbide ◽  
Flexural Strength ◽  
Xrd Analysis ◽  
Inert Atmosphere ◽  
X Ray Diffraction ◽  
Infiltration Process ◽  
Silicon Melt ◽  
Melt Infiltration ◽  
Similar Density ◽  
Porous Sic

Porous silicon carbide with mimicking the original microstructure of wood are prepared by pyrolysis and subsequently impregnated with silicon by silicon melt infiltration. The infiltration process was performed at 1500 °C for 3 hours holding times in inert atmosphere. Two types of wood were used as precursor which is Kapur and dark red Meranti.The morphology of resulting porous SiC have been investigated using scanning electron microscope (SEM/EDX) and X-ray diffraction (XRD) analysis. The density of the samples was characterized by Archimedes methods. The excess of silicon was removed by etching with the mixture of hydrofluoric and nitric acid. The flexural strength was tested by the three-point flexural method at room temperature.It has been shown that the final SiC for both precursors have similar density. The existence of SiC was proved by the XRD result, whereas EDX analysis of silicon content revealed that the formation of silicon carbide in dark red Meranti is higher than that of Kapur. The flexural strength and modulus of dark red Meranti samples were much higher than those of the kapur samples because of higher formation of silicon carbide in dark red Meranti.  

Microstructure and Mechanical Property of MoSi2 Based Composites

2005 ◽  
Vol 475-479 ◽  
pp. 707-710 ◽  
Author(s):  
Sang Ll Lee ◽  
Jin Kyung Lee ◽  
Byeong Hyeon Min ◽  
Yun Seok Shin ◽  
Dong Su Bae ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Flexural Strength ◽  
Interfacial Reaction ◽  
Reaction Layer ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Laminate Composites ◽  
High Toughness ◽  
The Impact ◽  
Microstructure And Mechanical Property

This study dealt with both the strengthening of matrix and the suppression of interfacial reaction for the development of high toughness Nb/MoSi2 laminate composites. The impact values of Nb/MoSi2, Nb/MoSi2-SiC, Nb/MoSi2-ZrO2 laminate composites were investigated at the room temperature. The flexural strength of MoSi2 based composites containing SiC or ZrO2 particles were also evaluated at elevated temperatures. The reduction of reaction layer by the addition of ZrO2 particles led to the sufficient improvement in the impact value of Nb/MoSi2 laminate composites. The flexural strength of MoSi2-SiC and MoSi2-ZrO2 materials decreased at temperatures higher than 800 °C.

The effect of porous carbon preform and the infiltration process on the properties of reaction-formed SiC

Carbon ◽  
2004 ◽  
Vol 42 (8-9) ◽  
pp. 1833-1839 ◽  
Author(s):  
Yanxiang Wang ◽  
Shouhong Tan ◽  
Dongliang Jiang
Keyword(s):  
Porous Carbon ◽  
Infiltration Process ◽  
Carbon Preform

Influence of Density on the Microstructure, Mechanical, Electrical and Thermal Properties of Recrystallized Silicon Carbide

2016 ◽  
Vol 680 ◽  
pp. 93-98 ◽  
Author(s):  
Hua Nan Lv ◽  
Xiao Liang Zhang ◽  
Peng Zhao Gao ◽  
Dong Yun Li ◽  
Wen Xie ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Room Temperature ◽  
Mechanical Test ◽  
Volume Resistivity ◽  
Binding Force ◽  
Thermal And Electrical Properties

In this paper, influence of density on the microstructure, mechanical properties, thermal and electrical properties of recrystallized silicon carbide (RSiC) were investigated via XRD, SEM, mechanical test, thermal conductivity instrument and four-probe method, etc. The results showed that the main phase of the RSiC materials was 6H-SiC; The flexural strength and modulus of elasticity of RSiC materials increased with the increase of densities, and the flexural strength of it measured at 1400 °C increased about 10%-15% compared with that of at room temperature, while the modulus of elasticity at 1400°C were lower than that of at room temperature, resulting from the weakening of binding force between the Si and C atoms at high temperature; With the increase of temperatures, the thermal conductivity of the RSiC materials decreased, while it increased with the increase of RSiC density, when density of RSiC equaled to 2.60 g·cm­3, values of the thermal conductivity were 177.7 W·(m·K)­1 (RT) and 28.1 W·(m·K)­1(1300°C), respectively; The volume resistivity of RSiC materials dropped from 12.74 Ω·cm to 4.51 Ω·cm as the density of RSiC increased, the impurities played an more important role on this variety.

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

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