Time resolved insights into abnormal grain growth by in situ synchrotron measurements

Large oligo-crystalline or single-crystalline metallic materials are of great interest for numerous applications, and a recently developed strategy for promoting abnormal grain growth induced by a cyclic heat treatment opens up new opportunities to manufacture single crystals with a size of several centimeters. So far, the entire available knowledge on this kind of abnormal grain growth has been elaborated based on time discrete observations and, thus, detailed insights into the interplay of elementary mechanisms are still lacking in open literature. The present study reveals time resolved insights into this kind of abnormal grain growth for the first time. It was possible to break down the influence of the individual heat treatment phases by in situ synchrotron high energy X-ray diffraction analysis during cyclic heat treatment. The results obtained not only help to gain a deep understanding of the abnormal grain growth mechanisms, they will also be the basis for an adjustment of the cyclic heat treatment process to improve its efficiency and to eventually obtain even larger single crystals