Elastic-Plastic Deformation of KDP Crystals under Nanoindentation
Elastic-Plastic Deformation of KDP Crystals under Nanoindentation
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DOI：
10.4028/www.scientific.net/msf.773-774.705
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发表时间：
2013-11
期刊：
影响因子：
--
通讯作者：
Jing-Rui Peng;Liangchi Zhang;Xinchun Lu
中科院分区：
文献类型：
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作者：
Jing-Rui Peng;Liangchi Zhang;Xinchun Lu
利用锥形金刚石压头对磷酸二氢钾（KDP）晶体的力学性能进行了研究。研究发现，当卸载发生在第一次弹入之后时，由于卸载过程是非弹性的，通常的由纳米压痕卸载曲线求取弹性模量的方法不再适用。研究表明，弹出可能是由于位错成核和传播，第一弹出下发生的应力低于主要位错爆发。因此，宏观屈服点，这通常被认为是一种材料的塑性开始，是纳米尺度上的KDP中的第一个位错的临界点。研究发现，KDP（001）面压痕的弹性模量为52.8±3.8GPa。材料的硬度为1.89±0.05GPa。
This paper investigates the mechanical properties of potassium dihydrogen phosphate (KDP) crystals with the aid of nanoindentation using a conical diamond indenter. It was found that when unloading is after the first pop-in, the common method of obtaining elastic modulus from the unloading curve of nanoindentation is no longer applicable, because the unloading is inelastic. The study revealed that the pop-in could be due to dislocation nucleation and propagation, and that the first pop-in occurs under a stress below that of the major dislocation burst. Hence, the macroscopic yielding point, which is usually regarded as the onset of plasticity of a material, is nanoscopically not a critical point of the first dislocation in KDP. The study found that the elastic modulus of KDP indenting on its (001) plane is 52.8±3.8GPa. The hardness of the material is 1.89±0.05GPa.