Super-resolution 3D ultrasound tomography for material microstructure characterisation

用于材料微观结构表征的超分辨率 3D 超声断层扫描

• 批准号: 2815310
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2815310
• 关键词: Super; resolution; 3D; ultrasound; tomography

Ultrasonic tomography is a powerful non-invasive tool widely use in medical diagnostics as well as non-destructive testing. Conventional tomographic methods represent a model-based sound velocity reconstruction of a medium, which assigns every voxel a sound velocity representing local material properties. This type of signal processing can be performed, for example, using elastic guided wave measurements for a wall thickness mapping in pipes and plate-like structures, or for the human brain imaging inside the skull. Ultrasonic tomography, however, has substantial untapped potential for multispectral, aspect-dependent, and area-specific imaging. Non-destructive volumetric material characterisation is an important problem with a wide range of applications in many areas. For example, the knowledge of material microstructural parameters is crucial for accurately estimating the lifetime of safety critical components in aerospace (jet engines and landing gears) or energy sectors (nuclear power plants). Detailed microstructural examination of metallic components can be performed using several established characterisation methods, such as optical microscopy, X-ray, Electron Back-Scattered diffraction (EBSD). However, all these methods are restricted to surface or near surface inspections. Moreover, some techniques are essentially destructive (EBSD), require complex surface preparation and are limited to relatively small inspection regions. Therefore, there is a clear need for additional methods capable of quantifying material microstructure in large sample volumes. It is also critical that such techniques significantly reduce both the time and surface quality requirements compared to conventional methods such as optical microscopy and EBSD. This project is driven by the recent advances in defect characterisation using ultrasonic arrays, which are based on the analysis of backscatter patterns of small subwavelength targets. The main aim is to expand ultrasonic tomography functionality fundamentally to create an efficient tool to produce a quantitative map of microstructural parameters of metals corresponding to each local material region. This requires a fundamentally different and innovative imaging concept. The measurement set-up will be implemented in a robotic arm scanning system, which will allow to perform ultrasonic transmitter-receiver measurements for a wide range of incident and scattered angles. The imaging approach exploits time-reversal properties of sound wave propagation and is based on reversible forward- and back-propagation imaging operations.

超声波断层扫描是一种强大的非侵入性工具，广泛应用于医学诊断和无损检测。传统的断层扫描方法代表了基于模型的介质声速重建，它为每个体素分配了代表局部材料属性的声速。例如，可以使用弹性导波测量来执行这种类型的信号处理，以绘制管道和板状结构中的壁厚映射，或者用于头骨内的人脑成像。然而，超声断层扫描在多光谱、方位相关和区域特异性成像方面具有巨大的未开发潜力。无损体积材料表征是一个在许多领域都有广泛应用的重要问题。例如，材料微观结构参数的知识对于准确估计航空航天（喷气发动机和起落架）或能源部门（核电站）中安全关键部件的寿命至关重要。金属部件的详细微观结构检查可以使用几种已建立的表征方法进行，例如光学显微镜、X 射线、电子背散射衍射 (EBSD)。然而，所有这些方法都仅限于表面或近表面检查。此外，一些技术本质上是破坏性的（EBSD），需要复杂的表面处理并且仅限于相对较小的检查区域。因此，显然需要能够量化大样本量材料微观结构的其他方法。同样至关重要的是，与光学显微镜和 EBSD 等传统方法相比，此类技术可显着降低时间和表面质量要求。该项目是由使用超声波阵列进行缺陷表征的最新进展推动的，超声波阵列基于对小型亚波长目标的反向散射图案的分析。主要目标是从根本上扩展超声波断层扫描功能，以创建一种有效的工具来生成与每个局部材料区域相对应的金属微观结构参数的定量图。这需要一种根本不同的创新成像概念。测量装置将在机械臂扫描系统中实施，该系统将允许对各种入射角和散射角进行超声波发射器-接收器测量。该成像方法利用声波传播的时间反转特性，并基于可逆的前向和反向传播成像操作。