应材料科学与工程学院黄陆军教授的邀请，俄罗斯别尔哥罗德国立大学Sergey Zherebtsov教授于2023年8月7日（周一）举行学术讲座，欢迎感兴趣的师生参加。

讲座时间与内容：

2023年8月7日（周一），9：30 -11：00 (北京时间)

Deformation mechanisms in Ti-rich high-entropy alloys

讲座地点：材料楼521

摘要：

High-entropy alloys (HEAs) constitute a new class of metallic materials attracting increased attention due to unusual combination of mechanical and functional characteristics. One of a strategy to improve mechanical properties of high entropy alloys is associated with activation of various modes of deformation mechanisms (such as TRIP, TWIP or dislocation slip). The primary objective of the present study is to investigate deformation mechanisms of new Ti-rich bcc HEAs. Three alloys of Ti-Zr-Hf-Ta-Sn, Ti-Zr-Nb-Al-V and Ti-Zr-Nb-Al-Mo systems were considered. The studied alloys demonstrated very unusual combinations of mechanical properties depending on the operating deformation mechanisms. Specifically the Ti38Zr25Hf25Ta10Sn2 alloys demonstrated exceptionally high strain - hardening and ductility due to deformation-induced martensite transformation. The Al5Nb24Ti40V5Zr26 and Al4Mo4Nb8Ti50Zr34 high-entropy alloys in recrystallized conditions showed properties typical of gum like metals, i.e. high strength, low work hardening and rather large elongation. The manifestation of such behavior can be ascribed to the formation of dislocation channels due to the local disordering of the bcc matrix in shear planes.

个人简介：

Sergey Zherebtsov achieved his Ph.D. degree from Institute for Metals Superplasticity Problems, Ufa, Russia in 2002 and a Dr. habil., Phys. Metallurgy, Ural Federal University, Ekaterinburg, Russia in 2013. From 2002 to 2006, he worked in Ufa State Aviation Technical University as a lecturer (Ufa, Russia), Ibaraki University as a researcher (Hitachi, Japan), Institute for Metals Superplasticity Problems as a Research Associate (Ufa, Russia). In 2007, he joined in Belgorod State University and became a full-time professor. His research interests are about formation of ultrafine-grain microstructure in titanium and titanium alloys via warm large plastic working. Development of high-entropy alloys with specified structure and properties. Extensive TEM/SEM/EBSD studies of structural changes during plastic deformation. Effect of hot/warm/cold working on microstructure, including evolution of interphase and grain boundaries. Evaluation of mechanical properties of metals and alloys.

俄罗斯贝尔哥罗德国立大学的Prof. Sergey Zherebtsov长期从事钛合金以及钛基复合材料的研究工作，对钛合金以及钛基复合材料的研究现状和应用发展动态有深入的了解，在工程结构材料的仪器分析等方面积累了大量的经验，包括钛合金的塑性变形机理、再结晶、相变以及显微织构的演变。专注于塑性成形制备超细晶钛合金的研究，热/中温/冷加工对显微组织的影响，SEM/TEM/EBSD分析塑性变形过程中显微结构的变化，包括相界面和晶界的演变，对材料的室温/高温力学性能进行评价，确定微观结构-力学行为的关系。