A study of mechanical properties of pure and nitrogen-doped ultrananocrystalline diamond films under various loading conditions

作者：Shen Luming^*; Chen Zhen

来源：International Journal of Solids and Structures, 2009, 46(3-4): 811-823.

DOI：10.1016/j.ijsolstr.2008.09.036

• Ultrananocrystalline diamond
• Molecular dynamics
• Grain boundaries
• N-Doping
• Size effect
• Rate effect
• Temperature effect

To better understand the mechanical responses of ultrananocrystalline diamond (UNCD) under various loading conditions, a numerical study is performed to investigate the size, loading rate and temperature effects on the material properties of pure and nitrogen-doped UNCD films. Since the UNCD growth mechanism is not completely understood yet, a simple procedure by combining kinetic Monte Carlo and molecular dynamics (MD) methods is developed to form a polycrystalline UNCD block with an artificial grain boundary (GB). By randomly inserting different numbers of nitrogen IN) atoms into the GB of the resulting polycrystalline UNCD films, N-doped UNCD films can be formed. The responses of the simulated pure and N-doped UNCD films with various grain sizes are then investigated by applying displacement-control led tensile loading under different rates and temperatures in the MD simulations. The simulation results presented in this paper provide a better understanding of the combined size, rate and thermal effects on the material responses of pure and N-doped UNCD films.

• 出版日期2009-2
• 单位大连理工大学