氢在Nd晶体中行为的分子动力学模拟

The simulation of the hydrogen motion in the Nd crystal by molecular dynamic

由三维Mobius反演变换所得的金属Nd原子和H原子间的相互作用势和组合规则的方法得到的Nd H原子间的相互作用势 ,利用正则系统分子动力学算法研究了在一定加载应力强度因子K =0 .6MPam下 ,氢在Nd晶体中的行为。模拟结果表明 ,氢在Nd晶体裂尖富集成许多氢原子团或氢气团。这可用来部分地解释NdFeB稀土永磁体吸氢后的氢爆行为。

The 3 D Mobius inversion method is used to get the pair potentials of Nd atoms and H atoms, and combination rules are used to get the potential between Nd and H atoms. The motion of hydrogen in the Nd crystal with the structure of dhcp is studied by canonical ensemble molecular dynamics under certain stress with strength factor K =0.6 MPa m . The results show that the hydrogen atoms come together around the crack tip. Hydrogen atoms or hydrogen molecular clusters with different sizes are formed. Therefore the hydrogen embrittlement observed in the NdFeB permanent can be partly explained.