Effect of microstructure and grain boundary chemistry on slow crack growth in silicon carbide at ambient conditions
Effect of microstructure and grain boundary chemistry on slow crack growth in silicon carbide at ambient conditions
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DOI：
10.1016/j.jeurceramsoc.2015.02.020
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发表时间：
2015-08-01
影响因子：
5.7
通讯作者：
Vandeperre, L. J.
中科院分区：
文献类型：
--
作者：
Al Nasiri, N.;Ni, N.;Vandeperre, L. J.
碳化硅(SIC)越来越多地被用作室温结构材料，在不能总是排除水分的环境中使用。遗憾的是，几乎没有关于室温下碳化硅中慢裂纹扩展(SCG)的报道。为了解决这一问题，采用恒应力率和水中双扭转试验研究了碳化硅中的应力腐蚀。制备的碳化硅材料具有广泛的晶界化学成分和微观结构，这可能会影响其缓慢的裂纹扩展行为。为了分别阐明化学和微观结构的作用，采用碳和硼的固态烧结和氧化物添加剂的液态烧结来制备细晶和粗晶材料。Lp-SIC材料对SCG的敏感性是SS-SIC材料的三倍。此外，韧性较高的粗晶材料对SCG的敏感性低于细晶材料。(C)2015爱思唯尔有限公司。保留所有权利。
Silicon carbide (SiC) is being used increasingly as a room temperature structural material in environments where moisture cannot always be excluded. Unfortunately, there have been almost no reports on slow crack growth (SCG) in SiC at room temperature. To address this gap, SCG in SiC was studied using constant stress rate and double torsion tests in water. SiC based materials were produced with a wide range of grain boundary chemistries and microstructures, which may affect their slow crack growth behaviour. To clarify the role of chemistry and microstructure respectively, solid state (SS) sintering with carbon and boron along with liquid phase (LP) sintering using oxides additives were used to produce materials with fine and coarse grains. The LP-SiC was three times more sensitive to SCG than SS-SiC materials. Moreover, the larger grained material with a higher toughness was less sensitive to SCG than the materials with fine grains. (C) 2015 Elsevier Ltd. All rights reserved.