1. Atomistic origin of brittle-to-ductile transition behavior of polycrystalline 3C–SiC in diamond cutting.
- Author
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Zhao, Liang, Hu, Wangjie, Zhang, Qiang, Zhang, Junjie, Zhang, Jianguo, and Sun, Tao
- Subjects
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DIAMOND cutting , *CRYSTAL grain boundaries , *MOLECULAR dynamics , *BRITTLE fractures , *SURFACE morphology - Abstract
The machinability of hard brittle polycrystalline ceramic has a strong correlation with internal microstructures and their accommodated deformation behavior. In the present work, we investigate the mechanisms governing the brittle-to-ductile transition behavior of polycrystalline 3C–SiC in diamond cutting by means of molecular dynamics simulations. Simulation results reveal the co-existence of dislocation slip and amorphization-dominated ductile deformation and cracking along grain boundaries-mediated brittle fracture, as well as the correlation of individual deformation modes with machining force variation and machined surface morphology. In addition, inter-granular fracture, grain boundary sliding and grain pull-up are also operating brittle deformation modes of polycrystalline 3C–SiC. The strong competition between above heterogeneous deformation modes determines the brittle-to-ductile transition behavior in grooving of polycrystalline 3C–SiC. Simulation results also demonstrate that grain size has a strong impact on the brittle-to-ductile transition and material deformation behavior of polycrystalline 3C–SiC under diamond cutting. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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