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Twist-Activated Universal Kink Deformations Enabling High Plasticity in Layered Boron Nitride Ceramic
XiangYin Pan1, YinBo Zhu1, HengAn Wu1
1CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, China.
ACS Applied Materials & Interfaces
|November 7, 2025
Summary
Twisted-layer boron nitride (tBN) ceramics exhibit enhanced plasticity by forming stable kink patterns, overcoming the brittleness of conventional hexagonal boron nitride (hBN). Twisted interfaces reduce deformation barriers, enabling omnidirectional plastic behavior in bulk TS-BN.
Area of Science:
- Materials Science
- Nanotechnology
- Solid Mechanics
Background:
- Ceramics, including hexagonal boron nitride (hBN), are typically brittle due to covalent bonding, limiting their use in engineering applications.
- Recent studies show twisted-layer boron nitride (TS-BN) exhibits significant plastic strain, but the nanoscale mechanisms remain unclear.
Purpose of the Study:
- To investigate the role of twisted interfaces in nanoscale plastic deformation of twisted BN (tBN) multilayers.
- To compare plasticity mechanisms in tBN with conventional hBN multilayers, focusing on kink formation.
Main Methods:
- Large-scale molecular dynamics simulations were employed.
- Analysis focused on kink formation and deformation mechanisms under various loading conditions.
- Interlayer shear modulus and sliding energy barriers were calculated.
Main Results:
- hBN exhibits anisotropic kink deformation due to lattice direction-dependent slipping barriers, hindering bulk deformability.
- tBN readily forms stable, omnidirectional kink patterns, independent of in-plane direction.
- Twisted interfaces in tBN reduce interlayer shear modulus and sliding energy barriers by two orders of magnitude compared to hBN.
Conclusions:
- Twisted interfaces are crucial for enhancing nanoscale plastic deformation in layered materials like tBN.
- The density of twisted interfaces correlates with improved omnidirectional kink deformation capabilities.
- Mechanistic insights offer a generalizable strategy for improving the plastic deformation capacity of brittle layered materials.
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