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为研究AZ91D镁合金的力学行为,采用纳米压痕技术,测得随深度连续变化的载荷-位移曲线;根据Olive算法,利用接触刚度连续测量(CSM)技术,分别得到AZ91D镁合金纳米层和基体的硬度和弹性模量。建立二维有限元模型,考虑Berkovich压头和样品之间存在摩擦,对Antunes提出的反分析法进行优化,通过正向分析(纳米压痕实验)和反向分析(数值模拟)的对比,得到特征应力、特征应变、应变强化因子,继而确定初始屈服应力,得到表面纳米化后AZ91D镁合金纳米层和基体的弹塑性幂函数本构关系。
In order to study the mechanical behavior of AZ91D magnesium alloy, the load-displacement curve with continuous changes of depth was measured by nano-indentation technique. According to the Olive algorithm and continuous contact stiffness measurement (CSM) technique, AZ91D magnesium alloy nanostructures and matrix Hardness and modulus of elasticity. A two-dimensional finite element model was established. By considering the friction between the Berkovich indenter and the sample, Antunes’ optimization of back analysis was optimized. The comparison between the forward analysis (nanoindentation experiment) and reverse analysis (numerical simulation) The characteristic stress, the characteristic strain and the strain strengthening factor, and then the initial yield stress is determined. The constitutive relation between elastic and plastic power function of AZ91D magnesium alloy nano-layer and matrix after surface nanocrystallization is obtained.