Elfallagh F, Inkson B J
Department of Engineering Materials, The University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom.
J Microsc. 2008 May;230(Pt 2):240-51. doi: 10.1111/j.1365-2818.2008.01981.x.
Three-dimensional focused ion beam (FIB) tomography is increasingly being used for 3D characterization of microstructures in the 50 nm-20 microm range. FIB tomography is a destructive, invasive process, and microstructural changes may potentially occur during the analysis process. Here residual stress and crack morphologies in single-crystal sapphire samples have been concurrently analyzed using Cr3+ fluorescence spectroscopy and FIB tomography. Specifically, maps of surface residual stress have been obtained from optically polished single-crystal alumina [surface orientation (1 ī 0 2)], from FIB milled surface trenches, from Vickers micro-indentation sites (loads 50 g-300 g), and from Vickers micro-indentation sites during FIB serial sectioning. The residual stress maps clearly show that FIB sputtering generates residual stress changes. For the case of the Vickers micro-indentations, FIB sputtering causes significant changes in residual stress during the FIB tomographic serial sectioning. 3D reconstruction of the crack distribution around micro-indentation sites shows that the cracks observed are influenced by the location of the FIB milled surface trenches due to localized stress changes.
三维聚焦离子束（FIB）断层扫描越来越多地用于对50纳米至20微米范围内的微观结构进行三维表征。FIB断层扫描是一个破坏性的侵入性过程，在分析过程中微观结构可能会发生潜在变化。在这里，使用Cr3+荧光光谱和FIB断层扫描同时分析了单晶蓝宝石样品中的残余应力和裂纹形态。具体而言，已从光学抛光的单晶氧化铝[表面取向（1 ī 0 2）]、FIB铣削的表面沟槽、维氏微压痕部位（载荷50克至300克）以及FIB连续切片过程中的维氏微压痕部位获得了表面残余应力图。残余应力图清楚地表明，FIB溅射会产生残余应力变化。对于维氏微压痕的情况，FIB溅射在FIB断层扫描连续切片过程中会导致残余应力发生显著变化。微压痕部位周围裂纹分布的三维重建表明，观察到的裂纹受FIB铣削表面沟槽位置的影响，这是由于局部应力变化所致。
