北京高压科学研究中心
Center for High Pressure Science &Technology Advanced Research

Prof. Yonghai Yue [Beihang University]

Title: In situ study of the strengthening and toughening mechanisms of nano-based composites
Time: 9:00 - 10:00 AM, Thursday, May 20, 2021
Place: Conference room A417, HPSTAR (Beijing)
           Tencent meeting: https://meeting.tencent.com/s/L2SPTmX51jBs , Meeting ID: 752 655 929    
Host: Xiang Gao


Abstract:

         In this talk, Prof. Yue will introduce his recent work about the super hard and tough diamond. 

  The well known trade off between hardness and toughness makes simultaneous improvement of

  both properties challenging, especially in diamond. Here they report the structural characterization

  of adiamond composite hierarchically assembled with coherently interfaced diamond polytypes, 

  interwoven nanotwins and interlocked nanograins. The architecture of the composite enhances

  toughness more than nanotwinning alone, without sacrificing hardness.Singleedge notched beam

  tests yield a toughness up to five times that of synthetic diamond,even greater than that of magnesium

  alloys. When fracture occurs, a crack propagates through diamond nanotwins of the 3C (cubic) polytype

  along {111} planes, via a zigzag path. As the crack encounters regions of non 3C polytypes, its propagation

  is diffused into sinuous fractures,with local transformation into 3C diamond near the fracture surfaces.

  Both processes dissipate strain energy,thereby enhancing toughness.This work could prove useful in

  making superhard materials and engineering ceramics.


Biography of the Speaker:

Professor Yonghai Yue
College of Chemistry, Beihang University, Beijing China
Email: yueyonghai@buaa.edu.cn

· Education
2006.9-2012.7   Beijing University of Technology, Ph.D.

· Working Experience
2012.12-2016.7 Beihang University, Lecturer
2014.9-2015.9 Arizona State University, Visiting scholar
2016.7-2020.3 Beihang University Ass.Prof.
2020-present   Beihang University, Professor

· Research Interests
1. In-situ study ofstrengthening and toughening mechanism of structural materials;
2. Design and performancecharacterization of new lightweight and high-strength composites.

· Selected Publications
1. Yonghai Yue et al., Nature, 2020, 582, 370;
2. Yonghai Yue* and Lin Guo*, ACS Nano, 2019, 13, 4191;
3. Yonghai Yue* and Lin Guo*, Adv. Funct. Mater, 2018, 28, 1801614
4. YonghaiYue*, Lin Guo* and Xun Wang*, JACS, 2017, 139, 8579;
5. Yonghai Yue et al., Nature Communications, 2016, 7,12251.