合金元素对钢中NbC异质形核影响的第一性原理研究

发布时间：2018-03-03 10:13

本文选题：合金元素　切入点：异质形核　出处：《物理学报》2017年16期 　论文类型：期刊论文

【摘要】：为了探索不同合金元素对Nb C异质形核的影响,本文利用第一性原理研究了合金元素X(X=Cr,Mn,Mo,W,Zr,V,Ti,Cu和Ni)对ferrite(100)/Nb C(100)界面性质的影响,并且分析了上述合金元素掺杂前后界面的黏附功、界面能和电子结构.研究结果表明,Cr,V和Ti掺杂的界面具有负的偏聚能,说明它们容易偏聚到ferrite/Nb C界面,但Mn,W,Mo,Zr,Cu和Ni却难以偏聚到此界面.当Mn,Zr,Cu和Ni取代界面处的Fe原子后,界面的黏附强度降低,即这些合金减弱铁素体在Nb C上的形核能力.然而Cr,W,Mo,V和Ti引入界面后,其黏附功比掺杂前的界面要大,且界面能均降低,即提高了界面的稳定性.因此,W,Mo,V和Ti,尤其是Cr,能够有效地促进铁素体形核和细化晶粒.电子结构分析表明,Zr和Cu引入界面后,界面处的Zr,Cu原子和C原子的相互作用变弱;然而Cr和W引入界面后,Cr,W和C原子之间形成了很强的非极性共价键,提高了ferrite/Nb C界面的结合强度.
[Abstract]:In order to explore the effect of different alloying elements on NB C heterogeneity nucleation, the effect of alloying elements X _ (X _ (X) C _ (C)) on the interfacial properties of ferrite(100)/Nb / C _ (100) was studied by means of first-principles. The adhesion work of the interface before and after doping of the above alloy elements was also analyzed. The interfacial energy and electronic structure. The results show that the interface doped with Cr (Cr) V and Ti has negative segregation energy, which indicates that they tend to converge to the interface of ferrite/Nb C, but it is difficult to get to the interface between Cu and Ni. When the Fe atoms at the interface are replaced by mn, Zr, Cu and Ni, The adhesion strength of the interface decreases, that is, these alloys weaken the nucleation ability of ferrite on NB C. However, when the interface is introduced into the interface, the adhesion work is larger than that before doping, and the interfacial energy decreases. That is to say, the stability of the interface is improved. Therefore, WNMoV and Ti, especially Cr, can effectively promote the nucleation of ferrite and refine the grain size. The electronic structure analysis shows that the interaction between Zr-Cu atoms and C atoms at the interface becomes weaker after the introduction of Zr and Cu into the interface. However, after the introduction of Cr and W into the interface, a strong nonpolar covalent bond was formed between the Cr-W and C atoms, which improved the bonding strength of the ferrite/Nb C interface.
【作者单位】：上海大学材料科学与工程学院;江西理工大学冶金与化学工程学院;
【基金】：国家自然科学基金(批准号:51404113,51404110) 江西理工大学创新训练项目(批准号:XZG-16-08-14)资助的课题~~
【分类号】：TG142.1

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