Superalloys fracture process inference based on overlap analysis of 3D models

Abstract

Superalloy materials exhibit susceptibility to fracture failures stemming from the influence of thermomechanical factors. To comprehensively understand the fracture mechanisms, material properties, root causes of failure, and the subsequent optimization of alloys, a detailed analysis of the internal fracture process and the morphological traits of the fracture surface is imperative. Traditional analysis of fracture surfaces solely relies on 2D images, thus lacking crucial 3D information. Although in situ experiments can capture the fracture process, their effectiveness is confined to the specimen’s surface, precluding insight into internal changes. Here we introduce an integrated framework encompassing the process of 3D reconstruction of fracture surfaces, aiming to enhance the visual information obtained with micron-level accuracy, visual intuitiveness and sense of depth. Additionally, this framework also facilitates the scrutiny and inference of internal fracture processes. These results demonstrate that under specific service conditions, material deformation fracture probably stems from a combination of surface cracking and internal cracking rather than exclusively one or the other. Overall, our description and analysis of internally initiated cracking due to defects within the specimens can be beneficial in guiding future alloy design and optimization efforts. Xuecheng Zhang, Guanghao Guo and colleagues present a characterization method for analyzing metallurgical fracture processes that addresses the limitations of conventional 2D imaging acquisition by providing a comprehensive visual depiction of fracture surfaces in 3D space. The method involves in situ tensile testing of IN718 alloy specimens at different temperatures, capturing real-time changes in morphology using high-resolution electron microscopy imaging, and reconstructing 3D models of the fracture surfaces.