2025年11月5日、Associate Prof. Paraskevas Kontis によるご講演が第178回構材ゼミとして開催されました。
講演後の集合写真
Prof. Paraskevas Kontis（右から5番目）
日時：2025年11月5日（水曜日）13：30-14：30
場所：NIMS千現地区 先進構造材料研究棟5階カンファレンスルーム
講演題目：Understanding deformation mechanisms in superalloys through partitioning of solutes at crystal defects,
講演者：Associate Prof. Paraskevas Kontis, Department of Materials Science and Engineering, Faculty of Natural Sciences,
Norwegian University of Science and Technology (NTNU),
開催者：宇多田 悟志 (高信頼性耐熱材料グループ)
Abstract:
Solutes interact with crystal defects, e.g. dislocations and stacking faults, during deformation. These interactions result in microstructural and compositional alterations that control the high-temperature mechanical performance of superalloys. Recent technological breakthroughs in high-resolution characterization have enabled compositional imaging of solutes at the near-atomic scale, providing new insights into such interactions. Based on these findings, case studies on understanding deformation mechanisms in superalloys through partitioning of solutes at crystal defects will be presented. In particular, the role of oxidized carbides in acting as crack initiation sites by facilitating localized microstructural and compositional alterations in polycrystalline superalloys will be presented. In addition, the formation of undesirable precipitates controlling crack initiation during very high-cycled fatigue and out-of-phase thermomechanical fatigue of single crystal superalloys will be presented.