Nanoindentation deformation and cracking in sapphire
Nanoindentation deformation and cracking in sapphire
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DOI：
10.1016/j.ceramint.2019.02.022
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发表时间：
2019-06
影响因子：
5.2
通讯作者：
V. Trabadelo;Siddhartha Pathak;F. Saeidi;M. Parlińska-Wojtan;K. Wasmer
中科院分区：
文献类型：
--
作者：
V. Trabadelo;Siddhartha Pathak;F. Saeidi;M. Parlińska-Wojtan;K. Wasmer
单晶蓝宝石是一种各向异性材料，其力学行为取决于晶体取向。在这项工作中，进行了系统的研究，以调查的蓝宝石的变形和开裂的晶体取向的影响，通过纳米压痕使用球形压头。它的目的也在于确定的物理起源的“弹出”出现在纳米压痕曲线。为此目的，进行纳米压痕，其中负载增加直到检测到“弹出”，然后直接卸载。通过对压痕的SEM和TEM观察，得出了蓝宝石的变形机制取决于压头半径和所施加的压痕应力：对于较小的压头半径1和2 μm，只形成孪晶;对于较大的压头半径10 μm，孪晶的形成伴随着裂纹的扩展。还确定裂纹优先在（10 1 <$2“R-平面”中扩展。因此，本研究是对现有蓝宝石在球形纳米压痕下变形和开裂行为研究的补充和丰富。
Single crystal sapphire is an anisotropic material and its mechanical behavior depends on the crystallographic orientation. In this work, a systematic study is performed to investigate the effect of crystallographic orientation on the deformation and cracking of sapphire by means of nanoindentation using spherical indenters. It aims also at determining the physical origin of the''pop-in" appearing in the nanoindentation curves. For that purpose, nanoindentations were performed where the load was increased until the detection of the''pop-in", followed by direct unloading. After SEM and TEM observation of the indents, it is concluded that the deformation mechanisms of sapphire depend on the tip radius and the applied indentation stress: exclusively twin formation for the smaller 1 and 2 μm tip radii indenters and twin formation together with crack propagation for larger 10 μm tip radius spherical indenter. It was also determined that the cracks propagate preferentially in the (10 1¯ 2)''R-plane". Therefore, this study is supplement to and enrichment of existing studies on deformation and cracking behavior of sapphire under spherical nanoindentation.