Dynamic Mechanical Properties of 2D-C/SiC and 2D-SiC/SiC

2019 ◽  
Vol 956 ◽  
pp. 244-252
Author(s):  
Xiao Ju Gao ◽  
Chao Li ◽  
Hasigaowa ◽  
Zhi Peng Li ◽  
Yu Guang Bao ◽  
...  

The quasi-static and dynamic compressive mechanical behaviors of two kinds of fiber reinforced SiC-matrix composites including 2D-C/SiC and 2D-SiC/SiC were investigated. Their compressive behaviors of materials at room temperature and strain rate from 10-4 to 104 /s were studied. The fracture surfaces and damage morphology were observed by scanning electron microscopy (SEM). The results showed that the dynamic failure strengths of the two kinds of fiber reinforced SiC-matrix composites obey the Weibull distribution. The Weibull modulus of the two materials were 13.70 (2D-C/SiC) and 5.66 (2D-SiC/SiC), respectively. It was found that the two kinds of fiber reinforced ceramic matrix composites presented a transition from brittle to tough with the decrease of strain rate. The 2D-SiC/SiC materials demonstrated a more HYPERLINK "http://dict.cnki.net/dict_result.aspx?searchword=%e6%98%be%e8%91%97%e7%9a%84&tjType=sentence&style=&t=remarkable"significant strain rate sensitivity and smoother fracture surface compared to the 2D-C/SiC composites, implying that the former composites present brittle features. This was because the SiC/SiC composites possessed high bonding strength in interface of fiber/fiber and fiber/matrix is very strong.

Author(s):  
Longbiao Li

In this paper, a micromechanical fatigue life prediction method for fiber-reinforced ceramic-matrix composites subjected to stochastic overloading at room temperature is developed. Fatigue damage mechanisms in the matrix, interfaces, and fibers are characterized using different damage models. Relationships between the fatigue life and related degradation rate, stochastic overloading stress, and breakage of intact fibers are established. Experimental fatigue life of different C/SiC composites subjected to different stochastic overloading is predicted. For the same stochastic overloading condition, the degradation rate of fatigue life is the highest for cross-ply C/SiC composite, and the lowest for 2.5D C/SiC composite.


1985 ◽  
Vol 68 (1) ◽  
pp. C-27-C-30 ◽  
Author(s):  
T. Mah ◽  
M. G. Mendiratta ◽  
A. P. Katz ◽  
R. Ruh ◽  
K. S. Mazdiyasni

Author(s):  
Sung R. Choi ◽  
Robert W. Kowalik

Interlaminar crack growth resistances were evaluated for five different SiC fiber-reinforced ceramic matrix composites (CMCs) including three gas-turbine grade melt-infiltrated SiC∕SiC composites. Modes I and II crack growth resistances, GI and GII, were determined at ambient temperature using double cantilever beam and end notched flexure methods, respectively. The CMCs exhibited GI=200–500J∕m2 and GII=200–900J∕m2. All the composites (except for one SiC/CAS composite) showed a rising R-curve behavior either in mode I or in mode II, presumably attributed to fiber bridging (in modes I and II) and frictional constraint (mode II) in the wake region of a propagating crack. A glass fiber-reinforced epoxy polymer matrix composite showed typically two to three times greater GI and eight times greater GII, compared to the CMCs. An experimental error analysis regarding the effect of the off-the-center of a crack plane on GI and GII was also made.


Author(s):  
Sung R. Choi ◽  
Robert W. Kowalik

Interlaminar crack growth resistances were evaluated for five different SiC fiber-reinforced ceramic matrix composites (CMCs) including three gas-turbine grade MI SiC/SiC composites. Modes I and II crack growth resistances, GI and GII, were determined at ambient temperature using double cantilever beam (DCB) and end notched flexure (ENF) methods, respectively. The CMCs exhibited GI = 200–500 J/m2 and GII = 200–900 J/m2. All the composites (except for one SiC/CAS composite) showed rising R-curve behavior either in mode I or in mode II, presumably attributed to fiber bridging (in modes I and II) and frictional constraint (mode II) in the wake region of a propagating crack. A glass fiber-reinforced epoxy polymer matrix composite, used as comparison, showed typically 2-3 and 8 times greater in GI and GII, respectively, compared to the CMCs. Experimental error analysis regarding the effect of the off-the-center of a crack plane on GI and GII was also made.


2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Keqiang Zhang ◽  
Lu Zhang ◽  
Rujie He ◽  
Kaiyu Wang ◽  
Kai Wei ◽  
...  

Carbon fiber-reinforced silicon carbide (Cf/SiC) ceramic matrix composites have promising engineering applications in many fields, and they are usually geometrically complex in shape and always need to join with other materials to form a certain engineering part. Up to date, various joining technologies of Cf/SiC composites are reported, including the joining of Cf/SiC-Cf/SiC and Cf/SiC-metal. In this paper, a systematic review of the joining of Cf/SiC composites is conducted, and the aim of this paper is to provide some reference for researchers working on this field.


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