Fabrication and Mechanical Properties of SiCf/SiC Composites via Polycarbosilane Pyrolysis

2007 ◽  
Vol 336-338 ◽  
pp. 1254-1256
Author(s):  
Yi Fei Wang ◽  
Qing Song Ma ◽  
Jing Yang Mu ◽  
Jun Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Thermal Shock Resistance ◽  
Low Density ◽  
Sic Fiber ◽  
Shock Resistance ◽  
Strong Interfacial Bonding ◽  
Sic Composites

Continuous SiC fiber reinforced SiC composites were fabricated by PIP route and their microstructures and mechanical properties were characterized. The density, flexural strength and fracture toughness of the composites were 1.88 g/cm3, 307 MPa and 8.24 MPa⋅m1/2, respectively. The low mechanical properties were ascribed to low density and strong interfacial bonding. The composites exhibited poor oxidation and thermal shock resistance; however, they showed desirable thermal stability.

Effect of AlF3 Content on Microstructure and Properties of Mullite/Al2O3 Composite Ceramics

2018 ◽  
Vol 922 ◽  
pp. 62-67
Author(s):  
Ke Zheng Sang ◽  
Fan Wang ◽  
De Jun Zeng ◽  
Hong Wei Li
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Diameter Ratio ◽  
Pressureless Sintering ◽  
Composite Ceramics ◽  
Microstructure And Properties ◽  
Shock Resistance ◽  
Mullite Whiskers

To reinforce the mullite/Al2O3 composite ceramics through formation of mullite whiskers, the composite ceramics were prepared by pressureless sintering using different AlF3 content. The microstructure, porosity, fracture toughness and thermal shock resistance of the composite ceramics were investigated. The results show that the addition of AlF3 can promote the mullite whisker formations, and the whiskers with the size of 3～10μm in diameter and a length-diameter ratio of 10～15 are obtained by sintering at 1600°C with the AlF3 content of 5wt%. Fracture toughness and thermal shock resistance of the composite ceramics are improved by the formation of mullite whisker. The fracture toughness of 4.79MPa•m1/2 can be obtained, and the 95.18% flexural strength remained after thermal shock.

Effect of Processing Condition on the Microstructure and Mechanical Properties of Ti3SiC2/SiC Composites

2010 ◽  
Vol 658 ◽  
pp. 352-355 ◽  
Author(s):  
Hong Feng Yin ◽  
Lin Lin Lu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Processing Condition ◽  
High Porosity ◽  
Pressing Temperature ◽  
Pressing Method ◽  
Microstructure And Mechanical Properties ◽  
Sic Composites

Ti3SiC2/SiC composites were fabricated by reactive hot pressing method. Effect of processing condition on the microstructure and mechanical properties of the composites were investigated. The results showed that: (1) Hot-pressing temperature influenced the phase constituent of Ti3SiC2/SiC composites. The flexural strength and fracture toughness of composites increased with hot pressing temperature. (2) The flexural strength and fracture toughness of composites increased when the content of SiC was increased. When the SiC content was 30wt% the flexural strength and fracture toughness of Ti3SiC2/SiC composite were 371MPa and 6.9MPa•m1/2 respectively. However, when the content of SiC reached 50wt%, the flexural strength and fracture toughness of composites decreased due to high porosity in the composites. (3) The flexural strength and fracture toughness of composites increased with the particle size of SiC added in composites. (4) Ti3SiC2/SiC composites were non-brittle at room temperature.

The Thermal Shock Resistance of Mg-PSZ/LaPO4 Ceramics

2013 ◽  
Vol 785-786 ◽  
pp. 187-190
Author(s):  
Zhong Qiu Li ◽  
Li Jie Ci ◽  
Tie Cheng Feng ◽  
Shao Yan Zhang
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Strength Degradation ◽  
Water Quenching ◽  
Bending Test ◽  
Three Point Bending ◽  
Shock Resistance ◽  
Thermal Shock Behavior

The mechanical properties and thermal shock behavior of Mg-PSZ/LaPO4 ceramics was investigated. The thermal shock resistance of the materials was evaluated by water quenching and a subsequent three-point bending test to determine the flexural strength degradation. Mg-PSZ/15LaPO4 composite showed a higher thermal shock resistance and behaved as a typical refractory. The calculation of thermal shock resistance parameters for the composites and the monolith had indicated possible explanations for the differences in thermal shock behavior.

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 Mechanical /thermal Shock Properties and Failure Mechanisms of Cf/SiBCN Composites Effect of Sintering Densification and Fiber Coating

2021 ◽  
Author(s):  
Zi-bo Niu ◽  
BingZu Wang ◽  
Lijun Pan ◽  
Daxin Li ◽  
Dechang Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Thermal Shock ◽  
Carbon Fibers ◽  
Thermal Shock Resistance ◽  
Sintering Temperature ◽  
Failure Mechanisms ◽  
Fiber Coating ◽  
Shock Resistance ◽  
Fiber Matrix

Abstract In this work, resin derived carbon coating was prepared on carbon fibers by polymer impregnation pyrolysis method (PIP), and then Cf/SiBCN composites were prepared by hot pressing process. The effects of sintering densification and fiber coating on microstructure, mechanical properties, thermal shock resistance, and failure mechanisms of the composites were studied. Fiber bridging hinders the sintering densification, causing more defects in fiber-dense area and lower strength. However, higher sintering temperature (1800-2000℃) can improve mechanical properties significantly, including bending strength, vickers hardness, and elastic module, because further sintering densification enhances matrix strength and fiber/matrix bonding strength, while the change of fracture toughness is not obvious (2.24-2.38 MPa·m1/2) due to counteraction of higher debonding resistance and less pull-out length. However, fiber coating improves fracture toughness greatly via protecting carbon fibers from chemical corrosion and damage of thermal stress and external stress. Due to lower coefficient of thermal expansion, lower fiber loading ratio, less stress concentration at the fiber/matrix interface and better defect healing effect, lower sintering temperature favor thermal shock resistance of composites and thermal shock recession mechanisms are the damage of interface.

Effect of Y2O3/La2O3 Proportion on the Mechanical Properties of Cf/SiC Composites

2014 ◽  
Vol 971-973 ◽  
pp. 63-66
Author(s):  
Yun Long Zhang ◽  
Yu Min Zhang ◽  
Ming Hu ◽  
Jin Ping Li
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Crack Deflection ◽  
Matrix Composites ◽  
Fiber Pullout ◽  
Molar Proportion ◽  
Sic Composites

In this paper, the commercial α-SiC powder and bargain price La2O3/Y2O3 additives were utilized to fabricate SiC matrix composites. The influence of the Y2O3/La2O3 molar proportion on the microstructure, mechanical properties of the Cf/SiC composites were researched. The results showed that La2O3/Y2O3 additives could not enhance mechanical properties for the Cf/SiC composites distinctly. The flexural strength for the Cf/SiC composites with different Y2O3/La2O3 proportion was higher than 250MPa. The multi-toughening mechanics including grain bridge, crack deflection and fiber pullout were responsible for improvement of fracture toughness.

ESCO ALLOY 72

Alloy Digest ◽  
1966 ◽  
Vol 15 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Thermal Shock Resistance ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Corrosive Media ◽  
Temperature Performance ◽  
Cobalt Base Alloy ◽  
Shock Resistance ◽  
Cobalt Base

Abstract ESCO Alloy 72 is a cobalt-base alloy having high corrosion, heat and thermal shock resistance. It is recommended for applications requiring good mechanical properties at elevated temperatures and/or in corrosive media. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Co-48. Producer or source: ESCO Corporation.

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