热镀Ni_3Al耐蚀合金镀层液态冷凝过程的分子动力学模拟研究

Molecular Dynamics Simulations of Corrosion Resistant Alloy Ni_3Al in its Solidification

钢铁表面热镀 Ni3Al耐蚀合金过程中 ,涉及 Ni3Al合金在钢铁表面由液态冷凝为镀层 ,冷却速度对结构及性能影响很大。采用 F- S多体势对耐蚀液态合金 Ni3Al在不同冷却速度下的微观结构及其转变机制进行了分子动力学模拟 ,得到了不同冷速下各温度的双体分布函数 ;采用 HA键型指数法对其结构进行了分析 ,结果表明 :Ni3Al的结构及能量转变受冷速影响较大 ,快冷时形成非晶 ,而慢冷时出现明显结晶 。

During the hot dip process of the corrosion resistant alloy Ni 3Al on the surface of the steel, it involves the solidification from liquid to coating The cooling rate has great influence on the microstructure and the performance By means of molecular dynamics simulation technique, the solidification process of liquid alloy Ni 3Al has been performed The F S N body potentials have been adopted to describe the atomic interactions The structural features have been revealed with the pair distribution The variation of energy with the temperature and the relationship between the energy and the microstructure has also been studied It has been concluded that the cooling rates have important influence on the final structure of Ni 3Al The Ni 3Al becomes the glass state at the relatively high cooling rate(4×10 13 K·s -1 ), but crystallize out at the relatively low cooling rate(4×10 11 K·s -1 ) At the same cooling rate(4×1011 K·s -1 ), the Ni 3Al melts of which Al is more than Ni crystallize out