Engineering grain structure in metals through on-line laser ultrasonic imaging

性能工程中使用的材料(如金属和合金)都是由晶体(或颗粒)以及这些晶体的大小、取向和分布组成的，这些晶体的排列对材料的特性起着重要的作用。控制这种分布将提供一种有用的方法，以确保材料的性能符合设计要求。该项目将把表面声波超声成像技术与激光粉末床融合系统相结合。实验将允许将生产参数与材料颗粒分布的即时变化直接联系起来。这将允许控制颗粒分布和部件，因此材料的属性可以在空间上变化，以优化性能。这将使用与Aconity PBF机器集成的定制空间分辨率声谱仪进行研究。它将前一层的声像与后续层上的构建策略配准，以控制颗粒的分布(和方向)。

Materials used in performance engineering (e.g. metals and alloys) are made up of crystals (or grains) and the size, orientation and distribution of these crystals, the arrangement of these crystals plays a significant role in determining the material characteristics. Controlling this distribution will provide a useful way to ensure the properties of the materials made match the design requirements.This project will integrate a surface acoustic wave ultrasound imaging technique with a laser powder bed fusion system. The experiments will allow the direct linking of the production parameters with the immediate change to the material grain distribution. This will enable control of the grain distribution with in parts to be controlled so the properties of the material can be varied spatially to optimise performance.This will be investigated using a custom spatially resolved acoustic spectroscopy rig integrated with an Aconity PBF machine. It will register the acoustic image of the previous layer with the build strategy on subsequent layers to control the distribution (and orientation) of the grains.