Layer-defect toughened hierarchically structured diamond composites

Ma，Xiaoliang1; Shi，Liping1; Yang，Lin1,2; Yi，Jian3; Wang，Bo3; Li，Mingwei4; Zheng，Bing5; Hou，Chengyu6; Ye，Lin7; Zhong，Yesheng1; He，Xiaodong1,8

2023-02-17

10.1016/j.engfracmech.2023.109052

ENGINEERING FRACTURE MECHANICS   Impact Factor & Quartile

0013-7944

1873-7315

Recently synthesized diamond composites containing interfaced polytypes, nanograins, and nanotwins show exceptional fracture toughness. Layer defects with enlarged interlayer distances and substantial sp bonding are commonly observed in such diamond composites. By using molecular dynamics simulations, we demonstrate that twin boundaries and phase boundaries have limited effect on toughening of the diamond composite. A diamond toughening mechanism that inhibits crack propagation and reduces crack tip stress intensity by introducing layer defects is demonstrated. Stress concentration around the crack tip can cleave nonpenetrating layer defects into partially deflected cracks, which dissipate fracture energy and stress concentration over a larger space region compared with a defect-free model, increasing fracture toughness. The toughening mechanism offers fundamental insight into understanding the fracture toughness of hierarchically structured diamond and is verified via comparison to previously published experimental results. The tradeoff between hardness and toughness in diamond composites may eventually be overcome by introducing these uniformly distributed layer defects.

Diamond composites Layer-defect Molecular dynamics Toughness

SCI

English

Others

National Natural Science Foundation of China (NSFC)[11872163] ; Shenzhen Science and Technology Program[KQTD2016112814303055] ; National Natural Science Foundation of Heilongjiang Province[LH2019F107] ; Project of the Chinese Academy of Sciences[XDC07030100]

Mechanics

Mechanics

WOS:000925239900001

PERGAMON-ELSEVIER SCIENCE LTD

ENGINEERING

2-s2.0-85146050190

Scopus

1.National Key Laboratory of Science and Technology on Advanced Composites in Special Environments,Center for Composite Materials and Structures,Harbin Institute of Technology,Harbin,150080,China
2.School of Aerospace,Mechanical and Mechatronic Engineering,The University of Sydney,2006,Australia
3.Key Laboratory of Marine Materials and Related Technologies,Zhejiang Key Laboratory of Marine Materials and Protective Technologies,Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo,315201,China
4.School of Material Science and Engineering,Harbin Institute of Technology,Harbin,150001,China
5.Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Materials Science,Heilongjiang University,Harbin,150001,China
6.School of Electronics and Information Engineering,Harbin Institute of Technology,Harbin,150080,China
7.School of System Design and Intelligent Manufacturing,Southern University of Science and Technology,Shenzhen,518055,China
8.Shenzhen STRONG Advanced Materials Research Institute Co.,Ltd,Shenzhen,518000,China

Ma，Xiaoliang,Shi，Liping,Yang，Lin,et al. Layer-defect toughened hierarchically structured diamond composites[J]. ENGINEERING FRACTURE MECHANICS,2023,279.

Ma，Xiaoliang.,Shi，Liping.,Yang，Lin.,Yi，Jian.,Wang，Bo.,...&He，Xiaodong.(2023).Layer-defect toughened hierarchically structured diamond composites.ENGINEERING FRACTURE MECHANICS,279.

Ma，Xiaoliang,et al."Layer-defect toughened hierarchically structured diamond composites".ENGINEERING FRACTURE MECHANICS 279(2023).