DAC加载金刚石和样品变形实验与模拟研究  

Experimental Study and Numerical Simulation on Deformation of Diamond and Sample under DAC Loading

作　　者：敬秋民[1] 吴强[1] 毕延[1] 于继东[1] 徐济安[1] 

机构地区：[1]中国工程物理研究院流体物理研究所冲击波物理与爆轰物理实验室,四川绵阳621900

出　　处：《高压物理学报》2013年第3期411-416,共6页Chinese Journal of High Pressure Physics

基　　金：国防科技重点实验室基金(9140C6703031002)

摘　　要：针对压力梯度法屈服强度测量实验技术,通过金刚石压砧对Mo薄箔样品的压缩实验,结合有限元模拟对金刚石的弹性变形和样品的弹塑性变形历史的计算,分析了金刚石的弹性压缩变形和"杯形"变形(Cupping)对压力梯度法原位厚度测量以及样品表面压力分布的影响。结果表明,至少在实验最高压力31.0GPa以内,忽略金刚石的弹性压缩变形具有合理性,金刚石"杯形"变形较为明显,对有限元模拟和实验测量给出的压力分布曲线分析表明,该变形使台面边沿样品表面的压力分布略微偏低,但在31.0GPa以内,对压力分布以及压力梯度没有影响。在压力达到60GPa时,台面"杯形"变形已经导致压砧边沿接触,实验设计上给出了降低"杯形"变形的建议。The compression experiment of molybdenum foil combined with finite element modeling calculation reveals the history of elastic deformation of diamond and elastic-plastic deformation of sample in the pressure gradient method used for measurement of yield strength at high pressures. The influence from elastic compression and cupping of diamond on the in situ thickness measurement and pressure profiles of molybdenum foil is analyzed. The results show that the elastic compression of diamond is very small and reasonable to ignore at least below 31 GPa which is the highest experimental pressure. The cupping of diamond is somewhat notable. But the agreement of pressure profiles and their pressure gradients between calculation and experiment indicate no evident change due to the influence of cupping of diamond below 31 GPa. The cupping finally leads to the contact of corners of culets at 60 GPa. The proposals of experimental design are also given to reduce the influence from cupping deformation of diamond at high pressure.

关 键 词：屈服强度 有限元模拟 弹性压缩 杯形变形 

分 类 号：O521.2[理学—高压高温物理]