基于Berkovich压入氮化硅断裂韧性实验验证虚拟裂纹闭合法的有效性  

Verification for the Effectiveness of Virtual Crack Closure Technique by Indentation Fracture Toughness Tests on Silicon Nitride with Berkovich Indenter

作　　者：王立志[1] 马德军[1] 孙亮[1] 石新正 高腾腾[1] 

机构地区：[1]装甲兵工程学院,北京100072

出　　处：《陶瓷学报》2017年第5期717-721,共5页Journal of Ceramics

摘　　要：依据Berkovich压入实验获得的压痕裂纹参数和加卸载曲线,通过有限元数值分析方法计算出氮化硅的弹性模量和屈服强度,然后采用虚拟裂纹闭合法计算其裂纹尖端应力强度因子KI,最终获得满足等KI准则的断裂韧性参数。结果表明,不同载荷下计算结果与氮化硅断裂韧性标准值之间的误差范围在-6.58%到-3.74%之间,因此本文所建立的Berkovich压入断裂韧性模型测试结果相对准确可靠,验证了虚拟裂纹闭合法的有效性,同时该方法可以为陶瓷材料的质量评价及工艺参数优化提供一定的技术手段和方法。According to the indentation crack parameters and loading-unloading curves obtained by Berkovich indentation test on silicon nitride, the elastic modulus and yield strength of silicon nitride are calculated by finite element method, and then the crack tip stress intensity factor（KI） is calculated by using virtual crack closure technique（VCCT）, finally the fracture toughness parameters satisfying thecriterion of equal KI are obtained. The results show that the errors range between the calculated results and standard fracture toughness value of silicon nitride is from-6.58% to-3.74%.So the test results of Berkovich indentation fracture toughness model are relatively accurate and reliable, and the validity of VCCT is verified. This work can provide technical means for the quality evaluation and parameter optimization of ceramic materials.

关 键 词：虚拟裂纹闭合法 Berkovich压头 陶瓷材料 断裂韧性 有限元分析 

分 类 号：TQ174.75[化学工程—陶瓷工业]