单斜氧化锆晶体压痕的分子动力学模拟研究

摘要

Molecular dynamics simulation was performed to study the deformation behaviors of monoclinic zirconia substrate for three different indentation orientations and different load speed during indentation.The coordination number were adopted to analyze the atomic configura-tion of the substrate and the variation of dislocations in different indentation depths.The P-h curves and deformation behaviors for various indentation orientations were compared.Three types of slip planes are observed in m-ZrO2 for three different indentation orientations;The (100) plane and (100)plane indentation produce obvious pile-up and sink-in phenomena,respectively, and the response of indentation shows dis continuous fluctuations in their P-h curves.Compari-son of the indentation results at three different velocity on (001)plane,reveals the significant in-fluence of the stress relaxation on the strain hardening and load fluctuation at low loading velecity.%利用分子动力学方法模拟研究了单斜氧化锆晶体在不同晶面和不同加载速率时压入的变形行为,并采用配位数方法分析了不同压痕深度下基体原子组态和位错的变化情况,比较了不同晶面压痕的载荷-位移曲线和变形行为.结果表明,三个不同晶面压入时单斜氧化锆晶体呈现出3种不同的滑移面;(100)和(001)面的压痕形貌分别表现出pile-up和sink-in现象,且在这两个面的压入响应均出现载荷-位移曲线的间断波动.对(001)面不同加载速率压痕的研究结果表明在低速率加载时应力驰豫现象对基体应变硬化与载荷波动现象影响显著.