超声相比较方法在固体弹性性能研究中的应用

ULTRASONIC PHASE COMPARISON TECHNIQUE AND ITS APPLICATION IN ELASTIC PROPERTIES RESEARCH IN THE SOLID

本文用超声相比较方法测量了几种不同类型材料(半导体GaAs晶体、含有Si_3N_4晶须结构的复合材料、过渡金属氧化物CoO以及高温超导体AgYBa_2Cu_3O-(7-?)的声速及后两种样品声速随压力、温度的变化,得到一些用超声脉冲回波重合法不易测定的结果。用相比较法测定声速具有测量频率范围宽、精度高、测量简便等持点,它能测量1mm左右厚度的薄样品以及声衰减较大的样品,是研究这些材料弹性性能的有效方法。

A ultrasonic interferometric technique-phase comparison method is introduced. As applications, the ultrasonic velocities propagating in semiconductor GaAs, composites with Si3N4 whiskers, transition metal oxide CoO and high Tc superconductor AgYBa2Cu3O7-b were measured. For the sample CoO and AgYBa2Cu3O7-b the dependence of ultrasonic velocities on both pressure and temperature also were measured.Using pulse echo overlap method, it is difficult to perform the above measurement. The phase comparison method makes measuring easy and accurate. It offers a wide measuring frequency range,from several megahertz to tens megahertz. The method can be used to measure ultrasonic velocities in thin samples (1-2mm)and in the samples that have serious ultrasonic attenuation. It is expected to obtain wide application in elastic properties research in the solid.