The effect of heat treatment on the strength and toughness of carbon fiber/silicon carbide composites with different pyrolytic carbon interphase thicknesses
The effect of heat treatment on the strength and toughness of carbon fiber/silicon carbide composites with different pyrolytic carbon interphase thicknesses
复制标题
热处理对不同热解碳界面厚度碳纤维/碳化硅复合材料强韧性的影响
DOI：
10.1016/j.carbon.2013.01.076
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发表时间：
2013-06-01
期刊：
影响因子：
10.9
通讯作者：
Cheng, Laifei
中科院分区：
文献类型：
--
作者：
Mei, Hui;Bai, Qianglai;Cheng, Laifei
研究了热处理对不同热解碳（PyC）界面厚度的碳纤维/碳化硅（C/SiC）复合材料强度和韧性的影响。结果发现，随着热处理温度（HTT）增加到1900 ℃，低强度试样（LSS，薄PyC约40 nm）的强度和韧性增加多达43.2%和274.0%，而高强度试样（HSS，厚PyC约140 nm）的强度和韧性分别显示出25.1%和14.8%的下降。LSS和HSS的弹性模量都随着HTT的增加而单调下降，而破坏应变总是变得更大，无论初始界面结合强度（IBS）。C/SiC的热处理机制被确定为（I）部分石墨化的PyC，削弱IBS，和（II）生产的缺陷，如基体裂纹/分层，界面脱粘和纤维断裂/拔出，导致热残余应力松弛。因此，热处理提高了具有相对高的IBS的LSS的强度和韧性，但对具有中等IBS的HSS的两个性能具有负面影响，因为过低的IBS和过度的应力释放阻碍了向纤维上的应力传递效率。(C)2013爱思唯尔有限公司保留所有权利。
The effect of heat treatment on the strength and toughness of carbon fiber/silicon carbide composites (C/SiC) with different pyrolytic carbon (PyC) interphase thicknesses was investigated. It was found that as the heat treatment temperature (HTT) increases to 1900 degrees C, the strength and toughness of a low strength specimen (LSS, thin PyC approximate to 40 nm) increase by as much as 43.2% and 274.0%, while those of a high strength specimen (HSS, thick PyC approximate to 140 nm) show decreases of 25.1% and 14.8%, respectively. The elastic moduli of both LSS and HSS monotonically decreased with increasing HTT while the failure strains always became larger regardless of the initial interfacial bonding strengths (IBS). The mechanisms involved in the heat treatment of the C/SiCs were identified as (I) partial graphitization of the PyC that weakens the IBS, and (II) production of defects such as matrix cracks/delamination, interfacial debonding and fiber fracture/pull-out that lead to thermal residual stress relaxation. Thus heat treatment improves the strength and toughness of LSS with a relatively high IBS, but has a negative impact on both properties of HSS with a moderate IBS because the stress transfer efficiency onto the fibers is hindered by the too low IBS and the excessive stress relief. (C) 2013 Elsevier Ltd. All rights reserved.