Development of Acoustic Microscope for High Attenuated and Anisotropic Inconel Alloy Welding Part

由于超声检测在很大程度上依赖于结构材料的超声速度的各向同性，因此必须研究超声速度的各向同性。由于各向异性行为具有复杂的局域分布，因此线焦光束声显微镜是最合适的各向异性测量系统。然而，由于各向异性材料容易表现出高衰减，声学显微镜通常不能应用于许多各向异性材料。在本研究中，我们利用汞耦合器代替传统的水耦合器，开发了一种新的高衰减材料声测量系统。研制了用于汞耦合器的新型声透镜和声扫描仪，获得了不能用水耦合器测量的不锈钢和铬镍铁合金的V(z)曲线。利用该声显微镜系统，清晰地观察了铬镍铁合金焊接部位附近的声图像，并利用汞耦合器定量测量了超声传播方向与速度的关系。结果表明，所研制的汞耦合器声显微镜系统可用于高衰减材料的声测量。

Since ultrasonic inspection depend strongly on the an isotropy in ultrasonic velocity of structural materials, an isotropy in ultrasonic velocity must be investigated. Most suitable measurement system for this an isotropy is Line-focus-beam Acoustic Microscope because anisotropic behavior has complicate and local distribution.However, Acoustic Microscope cannot usually applied for many anisotropic materials because anisotropic materials apt to show high attenuation. In this research, then, we develop the new Acoustic Measurement system for high attenuated materials by using Hg coupler instead of conventional water coupler. New types of acoustic lens and scanner were developped for Hg coupler and V(z) curve for stainless steel and inconel alloy were obtained which cannot measure by water coupler. By using these Acoustic Microscope system, acoustic Image near welding part of inconel alloy were clearly observed and quantitative velocity dependence of ultrasonic propagating direction were measured by Hg coupler. As the results, developped Hg coupler Acoustic Microscope system was useful for acoustic measurement of high attenuated materials.