Electrical Systems and Optics Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
J Acoust Soc Am. 2012 Aug;132(2):738-45. doi: 10.1121/1.4731226.
A previously described laser ultrasonic technique known as spatially resolved acoustic spectroscopy (SRAS) can be used to image surface microstructure, using the local surface acoustic wave (SAW) velocity as a contrast mechanism. It is shown here that measuring the SAW velocity in multiple directions can be used to determine the crystallographic orientation of grains. The orientations are determined by fitting experimentally measured velocities to theoretical velocities. Using this technique the orientations of 12 nickel and 3 aluminum single crystal samples have been measured, and these are compared with x-ray Laue backreflection (LBR) measurements with good agreement. The root mean square difference between SRAS and LBR measurements in terms of an R-value is less than 4.1°. The influence of systematic errors in the SAW velocity determination due to instrument miscalibration, which affects the accurate determination of the planes, is discussed. SRAS has great potential for complementary measurements or even for replacing established orientation determination and imaging techniques.
先前描述的一种激光超声技术，称为空间分辨声谱学 (SRAS)，可以用于通过局部表面声波 (SAW) 速度作为对比机制来对表面微观结构进行成像。本文表明，测量多个方向的 SAW 速度可用于确定晶粒的结晶方向。通过将实验测量的速度拟合到理论速度来确定取向。使用该技术，已经测量了 12 个镍和 3 个铝单晶样品的取向，并且与 X 射线劳厄背反射 (LBR) 测量结果具有良好的一致性。在 R 值方面，SRAS 和 LBR 测量之间的均方根差小于 4.1°。讨论了由于仪器校准错误而导致的 SAW 速度确定中的系统误差对准确确定平面的影响。SRAS 具有进行补充测量的巨大潜力，甚至可以替代现有的取向确定和成像技术。
