A study of mechanical properties of pure and nitrogen-doped ultrananocrystalline diamond films under various loading conditions
A study of mechanical properties of pure and nitrogen-doped ultrananocrystalline diamond films under various loading conditions
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DOI：
10.1016/j.ijsolstr.2008.09.036
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发表时间：
2009-02
影响因子：
3.6
通讯作者：
L. Shen;Zhen Chen
中科院分区：
文献类型：
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作者：
L. Shen;Zhen Chen
为了更好地了解超纳米晶金刚石(UNCD)在不同加载条件下的力学响应，数值研究了尺寸、加载速率和温度对纯UNCD薄膜和掺氮UNCD薄膜材料性能的影响。由于UNCd的生长机制尚不完全清楚，本文发展了一种结合动力学蒙特卡罗方法和分子动力学(MD)方法的简单方法，以形成具有人工晶界(GB)的多晶UNCd块。通过将不同数量的N原子随机插入到所得到的多晶UNCd薄膜的GB中，可以形成N掺杂的UNCd薄膜。然后在分子动力学模拟中，通过施加不同速率和温度的位移控制拉伸载荷，研究了模拟的不同颗粒尺寸的纯和N掺杂的UNCd薄膜的响应。本文给出的模拟结果有助于更好地理解尺寸、速率和热效应对纯和N掺杂的UNCD薄膜材料响应的影响。
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 (N) 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-controlled 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.