皇冠网上投注-皇冠网全讯网

報告題目：Study on nanoscale interface engineering in metal matrix composites

報告人：Gang JI（嵇罡）

報告人單位：University of Lille I（法國里爾第一大學）

報告時間：2023-11-13 09:30

會議地點：丁家橋校區科創大廈A1108會議室（騰訊會議：918-854-830）

舉辦單位: 先進輕質高性能材料研究中心

報告人簡介：Dr. G. JI obtained his Bachelor and Master degrees at Shanghai University in China and his Ph.D. degree atUniversité de technologie de Belfort Montbéliard (UTBM)in France. He joined CNRS as a permanent researcher in 2008. His current research interests include (1) design and engineering of interfaces of advanced metal matrix (nano-) composites for improved mechanical and thermal properties; (2) characterization and understanding of the metastable and anisotropic microstructure and defects in alloys and composites developed by additive manufacturing and (3) atomic-scale characterization for the local transformation of structure, chemistry and properties in complex multiphase materials. In his career to-date, Dr. JI has published around 120 peer-reviewed journal papers including Acta Mater., Angewandte Chimie, Nature Mater., (h-index: 40 from Google Scholar) and has around 100 contributions in international conferences. He is a member of editorial boards of journals “Nano Materials Science” and “Metals”. He was rewarded a 2016 Gledden Fellowship by University of Western Australia in Australia, 2023 IAAM scientist medal and is a guest Professor of the State Key Laboratory of Metal Matrix Composites at Shanghai Jiao Tong University in China.

報告摘要：The nature of the interface between ceramic reinforcement particles and metal matrix defines how such ceramic particles (CP) can be used to achieve favorable mechanical properties in metal matrix composites (MMCs). However, strength-ductility trade-off is usually an inevitable scenario in most MMCs where introduction of reinforcement particles significantly degrade ductility. The decrease of ductility is mainly attributed to dislocation pile-ups at the high mismatch interface between reinforcement particles and matrix, which cannot lead to effective dislocation multiplication and annihilation, finally leading to a low work hardening rate. To address this challenge, we propose a new precipitation-assisted interface tailoring (PAIT) mechanism to improve the coherency of interface between reinforcement particles and matrix by introducing a three-dimensional (3D) interphase (IP). Using a nano-TiB₂/Al-Zn-Mg-Cu composite as the model material, a Mg(Zn_1.5Cu_0.5) 3D IP is introduced by heat treatment to improve the coherency and strength of the TiB₂/Al interface with the aim of transforming the high mismatch TiB₂/Al interface into the low mismatch TiB₂/3D IP/Al multi-interfaces. This effectively promotes dislocation multiplication and subsequent dislocation annihilation to increase the work hardening rate by restricting the dislocation pile-ups surrounding the interface, thus leading to a higher ductility. In the second part of this talk, we will exploit the feasibility of optimal interface engineering in MMCsby rapid solidification techniques, such as laser direct energy deposition (L-DED) additive manufacturing.

審核：賈志宏