Espinoza Carolina, Feliú Daniel, Aguilar Claudio, Espinoza-González Rodrigo, Lund Fernando, Salinas Vicente, Mujica Nicolás
Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Avenida Blanco Encalada 2008, Santiago 8370449, Chile.
Departamento de Ingeniería Metalúrgica y Materiales, Universidad Técnica Federico Santa Maria, Av. España 1680, Valparaíso 2390123, Chile.
Materials (Basel). 2018 Nov 8;11(11):2217. doi: 10.3390/ma11112217.
The relative dislocation density of aluminum and copper samples is quantitatively measured using linear Resonant Ultrasound Spectroscopy (RUS). For each metallic group, four samples were prepared with different thermomechanical treatments in order to induce changes in their dislocation densities. The RUS results are compared with Nonlinear Resonant Ultrasound Spectroscopy (NRUS) as well as Second Harmonic Generation (SHG) measurements. NRUS has a higher sensitivity by a factor of two to six and SHG by 14⁻62%. The latter technique is, however, faster and simpler. As a main result, we obtain a quantitative relation between the changes in the nonlinear parameters and the dislocation density variations, which in a first approximation is a linear relation between these differences. We also present a simple theoretical expression that explains the better sensitivity to dislocation content of the nonlinear parameters with respect to the linear ones. X-Ray diffraction measurements, although intrusive and less accurate, support the acoustics results.
使用线性共振超声光谱法（RUS）对铝和铜样品的相对位错密度进行定量测量。对于每个金属组，制备了四个经过不同热机械处理的样品，以引起其位错密度的变化。将RUS结果与非线性共振超声光谱法（NRUS）以及二次谐波产生（SHG）测量结果进行比较。NRUS的灵敏度高出两到六倍，SHG的灵敏度高出14%-62%。然而，后一种技术更快、更简单。作为主要结果，我们得到了非线性参数变化与位错密度变化之间的定量关系，在一阶近似下，这些差异之间是线性关系。我们还给出了一个简单的理论表达式，解释了非线性参数相对于线性参数对位错含量具有更好的灵敏度。X射线衍射测量虽然具有侵入性且不太准确，但支持声学结果。
