Ceramic Physics Laboratory and Research Institute for Nanoscience, Kyoto Institute of Technology, Sakyo-Ku, Matsugasaki, 606-8585 Kyoto, Japan.
J Biomed Mater Res B Appl Biomater. 2010 Nov;95(2):250-62. doi: 10.1002/jbm.b.31706.
In-depth and in-plane response functions of photo- and electro-stimulated probes have been modeled and quantitatively evaluated in order to assess their suitability to detect the highly graded residual stress fields generated at the surface of alumina hip joints. Optical calibrations revealed large differences in probe size, which strongly affected the detected magnitude of residual stress. A comparison between the responses of Raman and fluorescence probes in polycrystalline alumina showed that the depth of those probes spread to an extent in the order of the tens of microns even with using a confocal probe configuration. On the other hand, the electro-stimulated luminescence emitted by oxygen vacancy sites (F(+) center) in the alumina lattice represented the most suitable choice for confining to a shallow volume the stress probe. This latter probe enabled us to reduce the measurement depth to the order of the tens of nanometers. We show maps of surface residual stress as collected on both main-wear and nonwear zones of an alumina femoral head. A comparison among stress maps taken at exactly the same location, but employing different probes, revealed averaging effects on the stress magnitude detected with photo-stimulated probes, while proving the superior spatial resolution of the electron probe.
为了评估其在探测氧化铝髋关节表面产生的高度梯度残余应力场的适用性，对光和电激发探针的深度和平面响应函数进行了建模和定量评估。光学校准显示探针尺寸存在很大差异，这强烈影响了残余应力的检测幅度。对比多晶氧化铝中拉曼和荧光探针的响应表明，即使使用共焦探针配置，那些探针的扩散深度也在数十微米的数量级。另一方面，氧化铝晶格中氧空位（F(+)中心）发出的电激发发光代表了将应力探针限制在浅层体积的最佳选择。这种探针使我们能够将测量深度降低到数十纳米的数量级。我们展示了在氧化铝股骨头的主磨损区和非磨损区收集的表面残余应力图。在同一位置采集的不同探针的应力图之间的比较表明，光激发探针检测到的应力幅度存在平均效应，而证明了电子探针具有更高的空间分辨率。
