Modeling Interfacial Evolutions at Atomistic Scale in the Process of Titanium Oxide Inducing Ferrite Nucleation in Steels
Modeling Interfacial Evolutions at Atomistic Scale in the Process of Titanium Oxide Inducing Ferrite Nucleation in Steels
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DOI：
10.1021/acs.cgd.1c01433
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发表时间：
2022-05
期刊：
影响因子：
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通讯作者：
Xinghu Yuan;Guocheng Wang
中科院分区：
文献类型：
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作者：
Xinghu Yuan;Guocheng Wang
采用第一性原理计算和Bramfitt错配理论研究了钢中钛氧化物夹杂物析出与铁素体形成的界面演化。结果表明，Fe（110）/Ti 2 O3（001）界面有9个可能的堆积位（Ti-O-1，Ti-O-2，Ti-O-3，Ti-Ti-1，Ti-Ti-2，Ti-Ti-3，O-Ti-1，O-Ti-2，O-Ti-3），Fe（100）/TiO 2（110）界面有3个可能的堆积位（O-1，Ti-1，Ti-2）。其中Ti-O-1、Ti-Ti-1和O-Ti-3为稳定界面，Ti-O-2、Ti-O-3、Ti-Ti-2、Ti-Ti-3、O-Ti-1和O-Ti-2为亚稳界面，在Fe（110）/Ti 2 O3（001）体系中有向稳定界面转化的趋势。在Fe（110）/Ti 2 O3（001）的所有稳定界面中，Ti-O-1界面具有最大的粘附功和最低的界面能值，这使得铁素体在Ti 2 O3表面形核的可能性最大。Fe（100）/TiO 2（110）体系中虽然所有界面都是稳定的，但它们具有负的粘附功和较大的界面能，导致TiO 2夹杂物不能促进铁素体形核。当铁素体在Ti-O末端的Ti 2 O3（001）表面形核时，它优先形成Ti-O-3界面，然后随着Fe原子的增加转变为Ti-O-1界面。此外，Mn掺杂Ti 2 O3的取代能和空位形成能表明，Ti 2 O3夹杂物可以以占据Ti原子空位的形式吸附Mn原子。
First-principles calculation and Bramfitt misfit theory are employed to investigate the interface evolution between the precipitated titanium oxide inclusions and forming ferrite in steels. The results showed that there are nine possible stacking sites (Ti–O-1, Ti–O-2, Ti–O-3, Ti–Ti-1, Ti–Ti-2, Ti–Ti-3, O–Ti-1, O–Ti-2, and O–Ti-3) for the Fe(110)/Ti2O3(001) interface and three stacking sites (O-1, Ti-1, and Ti-2) for Fe(100)/TiO2(110). Among them, Ti–O-1, Ti–Ti-1, and O–Ti-3 are stable interfaces, while Ti–O-2, Ti–O-3, Ti–Ti-2, Ti–Ti-3, O–Ti-1, and O–Ti-2 are metastable interfaces, which have a tendency to transform into stable interfaces in the Fe(110)/Ti2O3(001) system. The Ti–O-1 interface has the largest adhesion work and the lowest interface energy value in all stable interfaces of Fe(110)/Ti2O3(001), which leads to the maximum possibility of ferrite nucleation on the Ti2O3surface. Although all interfaces are stable in the Fe(100)/TiO2(110) system, they have negative adhesion work and quite large interface energy values, causing the fact that TiO2inclusion cannot promote ferrite nucleation. When ferrite nucleates on the Ti–O terminal Ti2O3(001) surface, it preferentially forms the Ti–O-3 interface and then transforms into the Ti–O-1 interface with increasing Fe atoms. Furthermore, the substitution and vacancy formation energy of Mn-doped Ti2O3show that Ti2O3inclusions can absorb Mn atoms in the form of occupying Ti atom vacancies.