IEEE Trans Ultrason Ferroelectr Freq Control. 2018 Apr;65(4):638-647. doi: 10.1109/TUFFC.2018.2796387.
Recent advances in computational methods, materials science, and new manufacturing processes are resulting in an unprecedented design flexibility which is driving the geometrical complexity of the components found in modern structures and machines. For safety-critical components, the geometrical complexity poses a significant challenge to the sensitivity of the existing nondestructive evaluation (NDE) methods available for the detection of manufacturing defects or damage that develops while a component is in service. Although X-ray computed tomography is the primary NDE method used to test these parts in current industrial practice, it is widely recognized that it has limited sensitivity to critical defects, such as cracks, especially in the presence of large size parts made of dense materials. The lack of sensitive NDE methods represents a major technology gap that could impede the acceptance of rapidly developing technologies, such as 3-D printing, for the production of safety-critical components. This paper attempts to bridge this gap by exploring the possibility of inspecting a complex-shaped part with ultrasonic waves after it has been encapsulated in ice, under the paradigm of what can be defined as cryo-ultrasonic NDE. The underpinning hypothesis is that through ice encapsulation a complex-shaped part can be transformed into a simple-shaped solid whose volume can be probed with ultrasonic waves, which are known to be highly sensitive to both pores and crack-like defects and over a wide range of material properties. Damage detection is then performed by analyzing cross-sectional images of the ice-encapsulated part obtained by applying migration methods to the ultrasonic signals measured by an array of transducers. This paper lays the foundation for cryo-ultrasonic NDE and presents the first experimental results demonstrating the possibility of imaging defects through multiple ice-metal interfaces. This paves the way to the detection of defects in complex-shaped parts containing internal vanes which have so far limited the use of conventional NDE methods.
最近，计算方法、材料科学和新制造工艺的进步正在带来前所未有的设计灵活性，从而推动了现代结构和机器中组件的几何复杂性。对于安全关键型组件，几何复杂性对现有无损检测 (NDE) 方法的灵敏度构成了重大挑战，这些方法可用于检测制造缺陷或在组件使用过程中发生的损坏。尽管 X 射线计算机断层扫描是当前工业实践中用于测试这些部件的主要 NDE 方法，但人们普遍认识到，它对关键缺陷（如裂纹）的灵敏度有限，特别是在存在由致密材料制成的大型部件的情况下。缺乏敏感的 NDE 方法代表了一个主要的技术差距，可能会阻碍快速发展的技术（如 3D 打印）在生产安全关键型组件中的应用。本文试图通过探索在将复杂形状的部件封装在冰中后，利用超声波对其进行检查的可能性，来弥补这一差距，这一方法可以被定义为低温超声 NDE。其基本假设是，通过冰封装，复杂形状的部件可以转变为简单形状的固体，其体积可以用超声波进行探测，而超声波对孔隙和类裂纹缺陷以及广泛的材料特性都非常敏感。然后通过对通过换能器阵列测量的超声波信号应用迁移方法获得的冰封装部件的横截面图像进行分析来执行损伤检测。本文为低温超声 NDE 奠定了基础，并提出了第一个实验结果，证明了通过多个冰-金属界面进行缺陷成像的可能性。这为检测包含内部叶片的复杂形状部件中的缺陷铺平了道路，而这些叶片迄今为止限制了常规 NDE 方法的使用。
