【摘要】 基于分子动力学模拟方法，探究以TiN为扩散介质时，N原子在α-Ti基体中的扩散行为。分析温度对N原子扩散速率、扩散路径及扩散产物结构的调控机制。通过原子运动轨迹重构与空间分布统计，直观呈现N在Ti基体中的扩散迁移路径；利用径向分布函数和原子数密度分布分析，表征扩散产物的短程有序结构及浓度梯度演变，明确温度对N扩散行为的影响。结果表明：扩散过程中TiN/Ti界面处的N首先开动，Ti-N键断裂；扩散产物以α-Ti间隙固溶体为主，另有少量Ti₃N、Ti₂N化合物；扩散行为主要发生在1200 K以上，且随着温度的升高N扩散速率呈指数级增加，900 K以下时仅有少量N扩散到α-Ti结构间隙中，TiN结构相对稳定；1200 K时N的扩散系数为2.5×10^-12 m²·s^-1,N在TiN/Ti界面处的扩散激活能为0.39 eV。钛材生产过程中，将加工温度控制在900 K以下可有效抑制TiN夹杂中N扩散造成的影响。更多还原

【Abstract】 Using molecular dynamics simulation methods to investigate the diffusion behavior of nitrogen（N） atoms in α-Ti matrix when TiN was used as a diffusion medium. The regulatory mechanisms of temperature on the diffusion rate of N atoms, diffusion pathways, and the structure of diffusion products were analyzed. By reconstructing atomic motion trajectories and analyzing spatial distribution, the diffusion migration pathways of N in the Ti matrix were visually presented. Using radial distribution functions and atomic number density distribution analysis, the short-range ordered structure and concentration gradient evolution of diffusion products were characterized, clarifying the effect of temperature on the diffusion behavior of N. The results show that during diffusion, N atoms at the TiN/Ti interface are activated first, and Ti-N bonds break. The diffusion products are mainly α-Ti interstitial solid solution, with a small amount of Ti₃N and Ti₂N compounds. Diffusion behavior mainly occurs above 1200 K, with the N diffusion rate increasing exponentially as temperature rises. In contrast, only minimal N diffuses into the interstitial sites of the α-Ti structure below 900 K, and the TiN structure remains relatively stable. At 1200 K, the diffusion coefficient of N is 2.5×10^-12 m²·s^-1, and the diffusion activation energy of N at the TiN/Ti interface is 0.39 eV. In titanium production, controlling the processing temperature below 900 K can effectively mitigate the effects of N diffusion from TiN inclusions.更多还原