主讲人：吴智鸿 西班牙马德里高等材料研究院
时间：2026年10月9号 上午10:30
地点：三一大楼506
报告摘要：
Rolling contact fatigue (RCF) causes severe subsurface microstructural degradation in high-carbon martensitic bearing steels, yet the formation of dark etching regions (DERs) and white etching bands (WEBs) and their associated carbon redistribution and carbide evolution remain controversial. Here, 100Cr6 bearing steel is investigated using interrupted fatigue testing and correlative multi-scale electron microscopy. A progressive transformation from severe plastic deformation and martensite decomposition to DERs and banded structures is revealed. DERs and banded structures consist of severely deformed ferritic grains. Carbon released during martensite and carbide decomposition segregates toward ferritic grain boundaries and reprecipitates as nanoscale carbides and continuous carbide films. These evolving microstructures also interact with surface-initiated crack propagation. The results provide a unified mechanistic picture of DER/WEB formation and direct evidence of carbon redistribution and carbide evolution during RCF.
主讲人简介：
Dr. Zhihong Wu has over eight years of research experience in metallic materials, with expertise in microstructural characterization, mechanical behavior, fatigue, and deformation mechanisms. He received his PhD in Materials Science from Northwestern Polytechnical University (NPU), China, in 2023. During his PhD, he conducted research at PSL Research University–Chimie ParisTech, France, focusing on deformation and fatigue mechanisms in titanium alloys. He subsequently joined the Technical University of Denmark (DTU) as a postdoctoral researcher, where he investigated rolling contact fatigue mechanisms in bearing steels. He is currently based at IMDEA Materials Institute, Spain, where his research focuses on advanced metallic alloys, phase transformations, and microstructural engineering.
