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为进一步了解SiC材料力学性能机理,采用Tersoff势对SiC在不同温度下初裂纹前缘沿[100]、[110]、[111]三个不同晶向的裂纹扩展进行了分子动力学模拟.裂纹前缘方向为[100]、[111]晶向的初裂纹扩展模拟结果表明:裂纹扩展方式为脆性解理断裂,低应力下裂纹尖端表面有无序带形成,在保证裂纹张开力作用下,裂纹尖端存在尖锐—钝化—尖锐的扩展过程.裂纹前缘方向为[110]晶向的初裂纹扩展模拟结果表明:裂纹出现明显“取向效应”,裂纹传播方向脱离了原有晶向(约60度)而选择沿其它晶向传播,裂纹扩展比较容易,裂纹断裂面几乎是完美的平面.
Abstract：Through molecular dynamics method with Tersoff potential,the propagation of thecracks is studiedin SiC under different temperatures,with the initial crackfront directions along[100],[110] and [111],respectively.The results showed that,it propagated by the mode ofcleavage fracture,at lowtension.For the crack with [100] or [111] beingthe crackfront,at lowtension,a disordered band formed at the crack tip,while under the tension that could guaranteethe crack to open,a sharpness—bluntness—sharpness propagation process at the crack tip.It iseasy for the crack with [110] direction to propagate,and during the propagation“orientationeffect”gradually appeared with about 60 degrees departure fromtheinitial direction.The surfaceof crack was al most plane.
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基本信息:
中图分类号:O346.1
引用信息:
[1]郭宗标,郭鹏,贾瑜.SiC沿[100]、[110]和[111]晶向断裂的分子动力学模拟[J].郑州大学学报(理学版),2007(02):171-176.
基金信息:
国家自然科学基金资助项目,编号10574113;; 河南省高校创新人才工程培养项目
2007-06-30
2007-06-30