提出一个晶粒与晶界的混和模型,用于计算单相纳米晶体陶瓷的弹性模量,进而结合Budiansky等人的自洽模型计算了含孔隙多相纳米晶体陶瓷的弹性模量。在此基础上,将正割模量替代弹性模量,在等应变假设的前提下,将提出的能计算含孔隙多相纳米晶体陶瓷弹性模量的模型拓展成能描述该类材料在小塑性变形条件下的应力-应变关系的模型,并且确定σ0.2为含孔隙多相纳米晶体陶瓷的屈服强度。大量计算结果与试验数据的对比表明,所提出的模型能较好地反映晶粒尺寸与孔隙率对纳米晶体陶瓷弹性模量与屈服强度的影响。
A calculation method is firstly proposed to describe the mechanical behavior of an individual phase of multi-phase nanocrystalline ceramics, and then Budiansky's self-consistent method is applied to calculate the elastic modulus of porous, multi-phase nanocrystalline ceramics. Further, the established method is extended to describe the stress-strain relations with small plastic deformation, and then the yield strength (σ 0.2) of porous, multi-phase nanocrystalline ceramics can be determined. In a word, the predictions are in good agreement with the results in the literature.