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2024年08月02日至2024年8月4日举行学术讲座，题目为“Effect of B2 ordering on properties of medium entropy alloys.”，欢迎感兴趣的师生参加。
讲座时间：2024年08月02日，10:00 (北京时间)
讲座地点：邵馆204会议室
讲座时间：2024年8月03日—2024年8月04日，10:00 (北京时间)
讲座地点：材料楼521会议室
邀请人：黄陆军 教授
摘要：Chemical ordering in body-centred cubic (bcc) refractory high/medium-entropy alloys (RH/MEAs), designed for high-temperature service, has been gained particular attention among the researchers in recent years due to crucial effect on the mechanical properties. Specifically a considerable enhancing the yield strength and uniform elongation can be attained by invoking of the B2 ordering and a further controlled increment of its degree during Al alloying. Such a strategy can result in a ∼ 37%-enhancement of both yield strength and uniform elongation in Alx(NbTiZr)100−x (x = 0; 2.5; 5; 7.5 at.%) refractory medium-entropy alloys. The improvement of properties stemmed from the solid solution and short-range order strengthening, as well as from the alteration in a character of dislocation glide. The B2 ordering caused the formation of multiple dislocation bands and the activation of cross-slip, which improved the macroscopic stability of plastic flow and extended the strengthening stage, thereby postponing necking.
Besides, with respect to a B2-ordered refractory Al15Nb40Ti40V5 medium-entropy alloy is was shown that the grain size, rather than the domain size, controlled room-temperature properties. Grain refinement to 20 μm at any size of B2 domains resulted in elongation of ~50%, which was superior to all the reported refractory high/medium-entropy alloys.
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. In 2024, he joined in Petersburg State Marine Technical University as 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.
