To comprehensively describe the size and strain rate dependent yield strength of monocrystalline ductile materials, a theoretical model was established based on the dislocation nucleation mechanism. Taking Ni3Al as an example, the model firstly fits results of molecular dynamics simulations to extract material dependent parameters. Then, a theoretical surface of yield strength is constructed, which is finally verified by available experimental data. The model is further checked by available third part molecular dynamics and experimental data of monocrystalline copper and gold. It is shown that this model can successfully leap over the huge spatial and temporal scale gaps between molecular dynamics and experimental conditions to get the reliable mechanical properties of monocrystalline Ni3Al, copper and gold.

为了综合考虑尺寸和应变率效应对单晶延性材料屈服强度的影响，建立基于位错形核机制的理论模型。以Ni_3Al为例，首先，通过分子动力学模拟结果拟合出材料参数；然后，通过材料参数构建屈服强度的理论曲面；最后，用现有实验数据检验该理论模型。通过现有第三方单晶铜和金的分子动力学和实验数据对该模型进行检验。结果表明，该模型可以跨越分子动力学和实验条件之间巨大的空间和时间差异，从而得到单晶Ni_3Al、铜和金的可靠力学性能。