Crystallographic Orientation Determination of Hexagonal Structure Crystals by Laser Ultrasonic Technique
Crystallographic Orientation Determination of Hexagonal Structure Crystals by Laser Ultrasonic Technique
复制标题
激光超声技术测定六方结构晶体的晶体取向
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
S. Sharples
中科院分区：
文献类型：
--
作者：
W. Li;J. Coulson;P. Marrow;R. Smith;S. J. Lainé;M. Clark;S. Sharples
空间分辨声学光谱（SRAS）是一种激光超声技术，可显示不同取向的晶粒之间的定性对比，说明声波对材料结构的敏感性。通过将测量的表面声波（SAW）速度与预先计算的模型进行比较，该技术在确定多晶粒立方金属的全取向方面得到了显着改进。在本文中，我们证明了这种技术的能力，以确定六方结构的晶体，如镁和钛基合金的取向。由于六方晶体基面（0001）上的声表面波速度各向同性，慢度表面呈现为圆形。当平面从（0001）向（112 ￣ 0）或向（101 ￣ 0）移动时，慢度面逐渐变成椭圆形。这些声学特性增加了取向确定的难度。本文介绍了一级工业纯钛的SRAS取向结果，并与电子背散射衍射（EBSD）结果进行了比较。由于六方结构晶体上SAW的性质，仅讨论了欧拉角1和2的结果。并对SRAS和EBSD之间的误差进行了分析。
Spatially resolved acoustic spectroscopy (SRAS) is a laser ultrasonic technique that shows qualitative contrast between grains of different orientation, illustrating the sensitivity of acoustic waves to the material structure. The technique has been improved significantly on determining the full orientation of multigrain cubic metals, by comparing the measured surface acoustic wave (SAW) velocity to a pre-calculated model. In this paper we demonstrate the ability of this technique to determine the orientation of hexagonal structure crystals, such as magnesium and titanium based alloys. Because of the isotropy of the SAW velocity on the basal plane (0001) of hexagonal crystals, the slowness surface is shown as a circle. As the plane moves from (0001) towards (112̄0) or towards (101̄0), the slowness surface gradually turns into an oval. These acoustic properties increase the difficulty in orientation determination. The orientation results of a grade 1 commercially pure titanium by SRAS is presented, with comparison with electron backscattered diffraction (EBSD) results. Due to the nature of SAWs on hexagonal structure crystals, only the results of Euler angles 1 and 2 are discussed. The error between SRAS and EBSD is also investigated.