Tensile Behavior of 2.5D C/SiCN Composites

2012 ◽  
Vol 217-219 ◽  
pp. 67-70
Author(s):  
Yi Xia ◽  
Hong Fang Li

Tensile behavior of C fiber reinforced amorphous SiCN ceramic matrix composites (C/SiCN ) were investigated by tensile machine. The microstructure morphologies were observed by scanning electron microscope. The results indicate that the tensile stress-strain curves of C/SiCN composites dispaly typical elastic deformation and cracks propagation stages. The 1500°C pre-sabilization treatment of C/SiCN in vacuum facilitates room temperature tensile stress growth. The higher treated temperature such as 1900°C is yet opposite. The reasons were attributed to thermal stress relaxation of C/SiCN after pre-stabilization treatment in vacuum.

Author(s):  
C. A. Nannetti ◽  
A. Borello ◽  
D. A. de Pinto ◽  
D. Carbone ◽  
A. Licciulli ◽  
...  

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.


2000 ◽  
Vol 15 (10) ◽  
pp. 2228-2237 ◽  
Author(s):  
Rhonda L. Callender ◽  
Andrew R. Barron

SiC, carbon, and Kevlart® fibers were coated with carboxylate–alumoxane nanoparticles and their calcium-, lanthanum-, and yttrium-doped analogs; firing to 1400 °C formed uniform aluminate coatings. Optimum processing sequences were determined. Both carboxylate–alumoxane- and ceramic-coated fibers were examined by field emission scanning electron microscopy, microprobe analysis, and optical microscopy. Coatings produced were stable to thermal cycling under air at 1400 °C. Fiber-reinforced ceramic matrix composites were prepared and results from 3-point bend tests for carbon/Kevlar®-fabric-reinforced ceramic matrix composites (CMCs) and carbon-fiber-reinforced CMCs were determined. Flexure strength for carbon-fiber- and carbon/Kevlart®-fiber-reinforced alumina CMCs was determined.


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.


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