Indentation size effect of germanium single crystal with different crystal orientations

不同晶体取向锗单晶的压痕尺寸效应

In order to study the indentation size effect(ISE)of germanium single crystals,nano-indentation experiments were carried out on the(100),(110)and(111)plane-orientated germanium single crystals.The true hardness of each crystal plane of germanium single crystals was calculated based on the Meyer equation,proportional sample resistance(PSR)model and Nix-Gao model,and the indentation size effect(ISE)factor of each crystal plane was calculated.Results show that,the germanium single crystals experience elastic deformation,plastic deformation and brittle fracture during the loading process,and the three crystal planes all show obvious ISE phenomenon.All three models can effectively describe the ISE of germanium single crystals,and the calculated value of Nix-Gao model is the most accurate.Compared with the other two crystal planes,Ge(110)has the highest size effect factor m and the highest hardness,which indicates that Ge(110)has the worst plasticity.

为了研究锗单晶的压痕尺寸效应,对(100)、(110)和(111)晶面取向的锗单晶进行纳米压痕实验。基于Meyer方程、比例试样阻力(PSR)模型和Nix-Gao模型计算锗单晶各晶面无压痕尺寸效应时的真实硬度值,并基于Manika幂律关系计算锗单晶各晶面的尺寸效应因子。结果表明:锗单晶在加载过程中发生弹性变形、塑性变形和脆性断裂3个阶段,且3个晶面均表现出明显的尺寸效应现象。3种模型均能较好地描述锗单晶的尺寸效应,其中Nix-Gao模型的计算值最为准确。相比于其他两个晶面,Ge(110)的尺寸效应因子m值最高,且具有最高的硬度值,表明该晶面的塑性性能最差。