MICROSTRUCTURE IMAGING USING FREQUENCY SPECTRUM SPATIALLY RESOLVED ACOUSTIC SPECTROSCOPY (F‐SRAS)
MICROSTRUCTURE IMAGING USING FREQUENCY SPECTRUM SPATIALLY RESOLVED ACOUSTIC SPECTROSCOPY (F‐SRAS)
复制标题
使用频谱空间分辨声波谱 (F-SRAS) 进行显微结构成像
DOI：
10.1063/1.3362405
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Somekh
中科院分区：
文献类型：
--
作者：
S. Sharples;Wenqi Li;M. Clark;M. Somekh
材料的微观结构可以对部件的机械性能产生深远的影响，如强度、抗蠕变和抗疲劳能力。SRAS(空间分辨声谱)是一种激光超声技术，它可以使用高度局域的表面声波(SAW)速度作为对比机制来成像微结构，因为这对晶体取向很敏感。该技术非接触、无损、快速，可用于大型部件，并具有高度的声学像差容忍度。以前，SRAS技术已经被证明使用固定频率的激励激光和可变的光栅周期(к矢量)来确定最有效地产生的SAW，从而确定速度。在这里，我们演示了一种使用宽带激光激励源的固定光栅周期的实现。通过对测得的频谱进行分析，确定了速度。给出了使用这种“频谱SRAS”(f-SRAS)方法的实验结果。伊玛..。
Material microstructure can have a profound effect on the mechanical properties of a component, such as strength and resistance to creep and fatigue. SRAS—spatially resolved acoustic spectroscopy—is a laser ultrasonic technique which can image microstructure using highly localized surface acoustic wave (SAW) velocity as a contrast mechanism, as this is sensitive to crystallographic orientation. The technique is noncontact, nondestructive, rapid, can be used on large components, and is highly tolerant of acoustic aberrations. Previously, the SRAS technique has been demonstrated using a fixed frequency excitation laser and a variable grating period (к‐vector) to determine the most efficiently generated SAWs, and hence the velocity. Here, we demonstrate an implementation which uses a fixed grating period with a broadband laser excitation source. The velocity is determined by analyzing the measured frequency spectrum. Experimental results using this “frequency spectrum SRAS” (f‐SRAS) method are presented. Ima...