Fabrication and Properties of Reaction Sintered SiC Based Materials

2004 ◽  
Vol 261-263 ◽  
pp. 1475-1480 ◽  
Author(s):  
Sang Ll Lee ◽  
J.O. Jin ◽  
Akira Kohyama
Keyword(s):  
Room Temperature ◽  
Composite System ◽  
Detailed Examination ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Complex Matrix ◽  
Sic Fiber ◽  
Sic Composites ◽  
Room Temperature Strength

The characterization of RS-SiC and RS-SiCf/SiC composite materials fabricated by the reaction sintering process has been investigated, based on the detailed examination of their microstructures. In this composite system, Tyranno SA SiC fiber and Hi-Nicalon SiC fiber were used as reinforcing materials. The green bodies for RS-SiC and RS-SiCf/SiC materials were prepared with the complex matrix slurry of SiC and C particles. The density and the room temperature strength of RS-SiC material with the starting SiC particles of 0.3 µm showed about 3.1 Mg/m3 and about 520 MPa, respectively, even if there were large amount of residual silicon (about 19 %). The flexural strength of Hi-Nicalon/SiC composites greatly decreased at the temperature higher than 1000 􀀀

Fabrication and Properties of Pressureless Sintered Si3N4/BN Composite Ceramics with La2O3-Al2O3-Y2O3 as Sintering Additives

2009 ◽  
Vol 620-622 ◽  
pp. 761-764
Author(s):  
Yong Feng Li ◽  
Ping Liu ◽  
Guan Jun Qiao ◽  
Jian Feng Yang ◽  
Hai Yun Jin ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Weight Ratio ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Composite Ceramics ◽  
Sintering Additives ◽  
Xrd Patterns ◽  
Room Temperature Strength

With commercial α-Si3N4 and h-BN powders as starting materials, La2O3, Al2O3, Y2O3 as sintering additives, Si3N4/BN composite ceramics with 25vol% h-BN were fabricated by pressureless sintering. Various amounts of La2O3 (0, 2, 4, 8, 15wt%) were added, with constant Y2O3/Al2O3 weight ratio and additives (Y2O3/Al2O3/La2O3) amount. The densification behaviors, α-βtransformation and room-temperature strength of Si3N4/BN composite were investigated. The porosity of samples decreased with La2O3 content increasing, and the lowest porosity of 20.83% was observed for samples containing 4wt% La2O3, then leaded to an increase. The flexural strength of all the specimens increased with the addition up to 4wt% and changed greatly thereafter. The highest room-temperature flexural strength, 272.4MPa, was obtained when 4wt% La2O3 was added. Results of XRD patterns revealed that β-Si3N4 and h-BN existed in all the specimens. No α-Si3N4 was detected, implying thatα- toβ-Si3N4 transformation has been completed during the pressureless sintering process. These results show that the La2O3-Al2O3-Y2O3 system can act as effective sintering additives for pressureless sintered Si3N4/BN composite.

Preparation and Characterization of SiC/MoSi2 Composites from Powder Resulting from a Mechanical-Assistant Combustion Synthesis Method

2010 ◽  
Vol 105-106 ◽  
pp. 70-74
Author(s):  
Jian Guang Xu ◽  
Hui Qiang Li ◽  
Hou An Zhang
Keyword(s):  
Mechanical Properties ◽  
Cyclic Oxidation ◽  
Room Temperature ◽  
Synthesis Method ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Oxidation Properties ◽  
Mosi2 Composite

SiC reinforced MoSi2 composites have been successfully prepared by pressureless sintering from mechanical-assistant combustion synthesized powders. The sintering temperatures and holding time were 1500°C~1650°C at a heating rate of 10K/min and 1 hour, respectively. The microstructure and mechanical properties of the as-sintered composites were investigated. SEM micrographs of SiC/MoSi2 composites showed that SiC particles were homogeneously distributed in MoSi2 matrix. The Vickers hardness, flexural strength and fracture toughness of the SiC/MoSi2 composites were up to 15.50GPa, 468.7MPa and 9.35MPa•m1/2, respectively. The morphologies of fractured surface of the composites revealed the mechanism to improve mechanical properties of MoSi2 matrix. At last, the cyclic oxidation behavior of the composites was discussed. The results of this work showed that in situ SiC/MoSi2 composite powder prepared by MASHS technique could be successfully sintered via pressureless sintering process and significant improvement of room temperature mechanical and anti-oxidation properties could be achieved.

Manufacture of Al/SiC Composites by Pressure Infiltration Process

2005 ◽  
Vol 475-479 ◽  
pp. 913-916
Author(s):  
Fa Zhang Yin ◽  
Cheng Chang Jia ◽  
Xuezhen Mei ◽  
Bin Ye ◽  
Yanlei Ping ◽  
...  
Keyword(s):  
Relative Density ◽  
Process Parameters ◽  
Room Temperature ◽  
Sintering Process ◽  
Homogeneous Microstructure ◽  
Infiltration Process ◽  
Pressure Infiltration ◽  
Upper Limit ◽  
Thermal Debinding ◽  
Sic Composites

The SiCp performing sample was made first then Al/SiCp (65%) was manufactured. Appropriate component and proportion of binder and process parameters were selected to control the porosity. Debinding has succeeded by extractive and thermal debinding processes. SiCp preforming samples with good appearance, enough strength, and right porosity were obtained by pre-sintering process at 1100°C. Composites with high density and homogeneous microstructure were manufactured by pressure infiltration under 1050°C and 15MPa. The distribution of aluminium and silicon elements was homogeneous. The primary components of materials are aluminium, β-SiC and α-SiC. The thermal expand coefficient of composites is 8.0×10-6/°C at room temperature, which increases with temperature and reaches to 11.0×10-6/°C at 300°C. The density is 2.92g/cm3, and relative density is more than 97 %. The strength is about 500MPa, approaching to the upper limit of the theoretical value.

Reaction Sintering and Characterization of Si/SiC Composites

1995 ◽  
Vol 108-110 ◽  
pp. 3-10 ◽  
Author(s):  
N. Thiyagarajan ◽  
S. Deb ◽  
Y.R. Mahajan
Keyword(s):  
Reaction Sintering ◽  
Sic Composites

Preparation and Characterization of Al2TiO5- Si3N4 Composites by Reaction Sintering Process

2011 ◽  
Vol 284-286 ◽  
pp. 201-204
Author(s):  
Rui Sheng Wang ◽  
Jun Hong Zhao ◽  
Heng Yong Wei ◽  
Shao Wei Yao
Keyword(s):  
Mechanical Strength ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Soaking Time ◽  
Sintering Properties ◽  
The One

Al2TiO5-Si3N4 composites were prepared by reaction sintering process using Al2TiO5 and α-Si3N4 powders as raw materials. The effect ofsintering temperature, soaking time and Si3N4 content on the sintering properties of the composites was studied. The results showed that the best sintering temperature and soaking time were 1550 °C and 2 h, respectively. The samples with 15 wt% of Si3N4 addition had good sintering properties, and its mechanical strength was 28.96 MPa, which was 2 times of the one of the samples without Si3N4 addition.

Mechanical Properties of SiC/FexSiy Composites

2011 ◽  
Vol 236-238 ◽  
pp. 1523-1527 ◽  
Author(s):  
Xiao Meng Zhang ◽  
Shu Feng Ye ◽  
Li Hua Xu ◽  
Peng Qian ◽  
Lian Qi Wei ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Flexural Strength ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Raw Material ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Scanning Electron

The SiC/FexSiycomposites were synthesized by reaction sintering process with iron tailings as raw material and carbon as reductant. The room and high temperature flexural strengths and fracture toughness of composites were studied in this paper. Fracture surfaces were observed by means of a scanning electron microscope (SEM). The results showed that the room temperature flexural strength of SiC/FexSiycomposites changed along with the different contents of FexSiyand sintering temperature. The flexural strength of composites reaches the maximum at 900°C. The correlation between flexural strength and temperature is consistent with curveⅠ.The fracture toughness of composites is related to the content of FexSiy. The fracture behavior of composites is mainly transcrystalline in room temperature and intercrystalline in high temperature.

Effect of Microstructure and Sintering Temperature on Fabrication of NITE-SiCf/SiC Composite

2007 ◽  
Vol 345-346 ◽  
pp. 1229-1232 ◽  
Author(s):  
Young Ju Lee ◽  
Han Ki Yoon
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
High Performance ◽  
Composite System ◽  
Matrix Composites ◽  
Practical Applications ◽  
Sic Fiber ◽  
Carbide Matrix ◽  
Sic Composites

Silicon carbide fiber-reinforced silicon carbide matrix composites (SiCf/SiC composites) are attractive materials for use in the blankets and divertors of fusion reactors due to their excellent thermo-mechanical properties and inherently low induced radioactivation. However, the brittle characteristics of SiC such as low fracture toughness and low strain-to fracture impose a severe limitation on the practical applications of SiC materials. SiCf/SiC composites can be considered as a promising candidate in various structural materials, because of their good fracture toughness. In this composite system, the direction of SiC fiber will give an effect to the mechanical properties such as fracture toughness and tensile strength. Therefore, it is important to control a proper direction of SiC fiber for the fabrication of high performance SiCf/SiC composites. .

scholarly journals Residual stress variation in SiCf/SiC composite during heat treatment and its effects on mechanical behavior

2020 ◽  
Author(s):  
Xiaowu Chen ◽  
Guofeng Cheng ◽  
Junmin Zhang ◽  
Feiyu Guo ◽  
Haijun Zhou ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Reduction ◽  
Tensile Strain ◽  
Room Temperature ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Stress Variation ◽  
Sic Fiber ◽  
The Matrix ◽  
Sic Composites

Abstract Residual stress originated from thermal expansion mismatch determines the mechanical properties of ceramic matrix composites (CMCs). Here, continuous SiC fiber reinforced SiC matrix (SiCf/SiC) composites were fabricated by nano-infiltration and transient eutectic-phase (NITE) method, and variation of residual stress in the constituent phases was investigated using high-temperature Raman spectrometer. With temperature increasing from room temperature to 1400°C, residual stresses of the matrix and the fiber decrease from 1.29 GPa to 0.62 GPa and from 0.84 GPa to 0.55 GPa in compression respectively, while that of the interphase decreases from 0.16 GPa to 0.10 GPa in tension. The variation of residual stress shows little effect in the tensile strength of the composites, while causes a slight decrease in the tensile strain. Suppression of fiber/matrix debonding and fiber pulling-out caused by the residual stress reduction in the interphase is responsible for the decreasing tensile strain. This work can open up new alternatives for residual stress analysis in CMCs.

Effect of B4C on the Mechanical Properties and Microstructure of ZrB2-SiC Based Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 218-221 ◽  
Author(s):  
Xuan Liu ◽  
Qiang Xu ◽  
Shi Zhen Zhu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Relative Density ◽  
Room Temperature ◽  
High Temperature Strength ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Room Temperature Strength

ZrB2-SiC-B4C is sintered at 1700°C by spark plasma sintering process. The effect of B4C content on the mechanical properties and microstructure of ZrB2-SiC based ceramics is studied. The results show that, with the content of B4C increases, the relative density and room-temperature strength decrease in the ZrB2-SiC-B4C composite. The fracture toughness rises at first and then falls down. The high temperature strength increases.

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