3-Dimensional Imaging of Macroscopic Defects in Aluminum Alloys: Image Reconstruction in 3D using Milling and Optical Microscopy

Abstract

Abstract The investigation of macroscale defects in aluminum (Al) alloys with a 3-dimensional (3D) imaging approach is described in this report. Aluminum (Al) alloys play an important role in the production of aircraft and vehicles, as well as products in other industries. Defects present in Al alloys used for the production of aircraft, vehicles, or other products can have a significant effect on their quality, performance, and lifetime. Characterization of Al alloys in 3D can lead to a better understanding of defect formation and how to minimize or eliminate it. To produce 3D images of defects in non-transparent Al alloy, the samples are milled in small steps (10 μm). Optical microscopy 2D images of the surface are recorded after a certain thickness of alloy (50 μm) is removed. From these 2D images, a 3D image of the Al alloy defect is reconstructed. The entire workflow for Al alloy sample preparation and 2D image recording is completed in a very short time (1.5 h) using a single instrument, the EM TXP surface preparation system from Leica Microsystems. Typically, the completion of such a workflow with more common sample preparation methods would be 3 to 6 times longer. Finally, 3D image reconstruction is done using the LAS X 3D Visualization software.