First-principles study on ferrite/TiC heterogeneous nucleation interface

doi:10.1016/j.jallcom.2012.12.099

Journal of Alloys and Compounds

Volume 556, 15 April 2013, Pages 160-166

https://doi.org/10.1016/j.jallcom.2012.12.099 Get rights and content

Abstract

Interface atomic structure, bonding character, cohesive energy and interfacial energy of ferrite (1 0 0)/TiC (1 0 0) were studied using a first-principles density functional plane-wave ultrasoft pseudopotential method. Meanwhile, the effectiveness of TiC as the heterogeneous nuclei of ferrite was analyzed. The results indicated that, TiC bonding is dominated by the C-2p, C-2s and Ti-3d electrons, which exhibits high covalency. With increase of the atomic layers, the interfacial energies of ferrite and TiC are both declined rapidly and stabilized gradually. There are two binding modes for TiC as the heterogeneous nuclei of ferrite, which are Fe atoms above the Ti atoms (Ti-termination) and Fe atoms above the C atoms (C-termination). Interfacial energy of the Ti-termination is larger than that of the C-termination, which means that for Fe atoms above the C atoms, the ability of TiC promotes ferrite heterogeneous nucleation on its surface is larger than that for Fe atoms above the Ti atoms.

Graphical abstract

Highlights

► Interface stability of ferrite (1 0 0)/TiC (1 0 0) was studied. ► The effectiveness of TiC as the heterogeneous nuclei of ferrite was analyzed. ► Ti-termination and C-termination are the two binding modes for ferrite/TiC interface. ► Interfacial energy of the Ti-termination is larger than that of the C-termination. ► On C-termination, ability of TiC promotes ferrite heterogeneous nucleation is strong.

Introduction

With high yield strength, excellent intergranular corrosion resistance and low crack tendency, ferrite steel has been widely used in the modern manufacturing industry [1], [2], [3]. After being in service for a period of time, the workpieces manufactured by ferrite steel usually failed because of excessive wear and corrosion [4]. The shape and size of the failed workpieces can be restored by means of remanufactured technologies, in which, the surface welding (surfacing) is one of the best effective methods [5], [6], [7], [8].

During the surfacing process, because the molten pool is cooled slowly, the ferrite in surfacing metal tend to grow into columnar crystal, which results in grain coarsen. Lee [9] showed that, if effective heterogeneous nuclei exist in the molten pool before the solidification, a large number of small ferrite equiaxed grains were formed in molten pool, which can replace the inherent columnar crystal and the center segregation can be reduced largely. Wang et al. [10], [11], [12] found that, by adding an appropriate amount of alloy element Ti in the surfacing metal, TiC grain which can be the effective heterogeneous nucleation of ferrite was formed obviously, thereby ferrite was refined. Cantor and Kim [13], [14] indicated that, in essentially, heterogeneous nucleation is a process, in which, nucleation phase atoms continuous growing up by adsorbed on the surface of the nucleation core.

First-principles calculation is an important microscopic research method, which is developed in recent years and has been widely used in modern science. Han et al. [15], [16] calculated the microscopic properties of TiB₂ particle and analyzed the mechanism of TiB₂ as the heterogeneous nuclei of the phase in Al-alloy by first-principles. Wang et al. [17], [18] researched the preparation of the Fe–Ti–N master alloy using first-principles, in which the ferrite can be refined by TiN. Liu et al. [19] studied the best geometric structure, thermodynamic property and electronic structure of NiAl (1 1 0)/Cr (1 1 0) interface based on a first-principles density functional plane-wave ultrasoft pseudopotential method, besides identified the interface stable structure thermodynamically and analyzed bonding characteristics among the interface atoms. Arya and Cater [20] analyzed the process of forming film between TiC and ferrite by first-principles, and showed that with increasing their packing densities, the stabilities of both TiC and ferrite surfaces are (1 1 0) < (1 1 1) < (1 0 0) for TiC and (1 1 1) < (1 0 0) < (1 1 0) for ferrite. However, the research on TiC as the heterogeneous nucleus of ferrite by first-principles has not been reported.

Therefore, the electronic structure combined power and interfacial energy between TiC (1 0 0) surface and ferrite (1 0 0) surface were calculated within atomic and electronic size scales using a first-principles density functional plane-wave ultrasoft pseudopotential method, which can provide theoretical basis for TiC as the heterogeneous nuclei of ferrite grain.

Section snippets

Calculation method

DFT (density functional theory) with ultrasoft pseudopotential is employed in the CASTEP (Cambridge Sequential Total Energy Package) mode, which utilizes plane-wave pseudopotential to perform first-principles quantum mechanics calculations [21], [22]. LDA (Local Density Approximation) with the CAPZ (Ceperley–Alder–Perdew–Zunger) functional and GGA (Generalized Gradient Approximation) with the PBE (Perdew–Burke–Ernzerhof) functional are employed as exchange–correlation functionals.

In order to

Bulk and surface calculations

The crystal structures of ferrite and TiC are body-centered cube and face-centered cube respectively, and their space group structures are IM–3M and FM-3M. Each ferrite cell contains two unit cell (Z = 2) and TiC cell contains four unit cell (Z = 4). The crystal structures of ferrite and TiC are shown in Fig. 1.

Establishment of the interface of ferrite/TiC

On the basis of calculated results above mentioned, the model of the ferrite/TiC interfaces uses a superlattice geometry, in which a 5-layer slab of ferrite (1 0 0) is placed on a 5-layer TiC (1 0 0) slab. The free surfaces of ferrite and TiC are separated by at least 12 Å vacuum. In addition, for interfacing the (1 0 0) planes, the slabs were oriented about an axis normal to the interface so as to align the [1 0 0] directions, resulting in a “cube-on-cube” orientation relationship [33]: ferrite [1 0 0] (1

Conclusion

Overall, a LDA-CAPZ study of the interface structure, cohesive energy, electronic structure, and bonding of the ferrite/TiC interface has been performed, in order to analyze the mechanism of TiC as the effective heterogeneous nuclei of ferrite. TiC bonding is dominated by the C-2p, C-2s and Ti-3d electrons. In essence, it is a mix bond composed by small portion of metallic bond and large portion of covalent bond and exhibited high covalency.

Structural relaxation of the TiC (1 0 0) and ferrite (1 0

Acknowledgments

The authors would like to express their gratitude for projects supported by Program for National Nature Science Foundation of China (51271163) and Key Project of Science and Technology of Hebei Province (09215106D).

References (38)

W. Wang et al.
Mater. Des.
(2009)
X.T. Zheng et al.
Int. J. Fatigue
(2011)
E. Badisch et al.
Tribol. Int.
(2010)
K.C. Hsieh et al.
J. Alloy Comp.
(2009)
Y.F. Zhou et al.
Appl. Surf. Sci.
(2012)
W.T. Kim et al.
Acta Metall.
(1994)
C. Wang et al.
J. Alloys Comp.
(2010)
C. Wang et al.
Solid State Commun.
(2010)
L.M. Liu et al.
Surf. Sci.
(2004)
M. Hakamada et al.
J. Alloy Comp.
(2010)

M. Tagawa et al.

Surf. Sci.

(2002)

D.J. Siegel et al.

Acta Mater.

(2002)

D.J. Siegel et al.

Surf. Sci.

(2002)

W.Y. Choe et al.

J. Alloy Comp.

(2001)

J.H. vander Merwe

Surf. Sci.

(2001)

M.M. Wu et al.

J. Alloy Comp.

(2011)

M.R. Krishnadev et al.

Metall. Mater. Trans. A

(1979)

X.H. Wang et al.

Surf. Coat. Technol.

(2009)

V.E. Buchanan et al.

Wear

(2008)

Cited by (52)

Effects of TiC addition on the interface stability, microstructure, and mechanical properties of IN718 fabricated by laser direct metal deposition: A combined experimental, DFT and MD study
2024, Intermetallics
In this study, we reveal the impact of the addition of TiC in the IN718 superalloys at both atomic and micron scales through density functional theory (DFT), molecular dynamics (MD), and experimental analysis. From the micro scales, the addition of TiC can effectively mitigate the segregation behavior of Nb and Mo atoms, promote heterogeneous nucleation, reduce grain size, and thus improve mechanical properties. From the atomic scales, the effect of alloying elements (Fe, Cr, Mo, Nb, Co) on the stability of the TiC/γ-Ni interface was investigated through first principles. Co-doping interface was more stable than other interfaces by MD calculations, followed by Cr and Fe-doping models. The heat of segregation results inferred that TiC can effectively mitigate the segregation behavior of Nb and Mo atoms in the TiC/γ-Ni interface, it is mutually verified with the experimental results. Furthermore, the interface energy values theoretically illustrated that TiC particles could promote the heterogeneous nucleation of γ-Ni, this behavior of TiC particles was verified by experiment results. This investigation results provide reference information in the study of ceramic particle reinforced alloys at atomic and micron scales.
Effects of Mn on the interface bonding and mechanical properties of TiC reinforced steel matrix composites
2024, Ceramics International
The addition of alloying elements to the steel matrix during the preparation process can significantly affect the properties of TiC reinforced steel matrix composites. In this study, the effects of Mn on the electronic structure and crystal structure stability of Fe supercells, along with as well as the stability of the TiC/Fe(Mn) interface, were analyzed through first-principles calculations. Additionally, 8 vol% TiC/Fe–C composites were prepared through the master alloy method. The effects of Mn contents (0, 0.8, 1.2, 1.6, and 2.0 wt%) on the interface mismatch and mechanical properties of the composites were investigated. The results revealed that Mn formed a solid solution and generated a stronger Fe–Mn bond compared with the Fe–Fe bond, and no interface chemical reaction occurred. The addition of a small amount of Mn improved the interface bonding between TiC particles and the steel matrix. The TiC particles were uniformly distributed in the matrix at the grain boundaries, with only a small amount dispersed within the grains. The TiC particles and steel matrix exhibited excellent, continuous, and stable interface bonding. The addition of Mn reduced the interface mismatch between TiC particles and the matrix. As the Mn content increased, the tensile strength and elongation of the composites first increased and then decreased, while the hardness of the composites increased. The addition of 1.2 wt% Mn resulted in an increase in the tensile strength, elongation, and hardness of the composite by 1160 MPa, 7.3%, and 43 HRC, respectively. These values were 109.8%, 151.7%, and 31.1% higher than those of the composite without Mn addition. However, an excess of Mn led to severe distortion of the Fe lattice and clustering at the interface, resulting in the degradation of the mechanical properties in the composites.
The adsorption behaviors of Cl<inf>2</inf> on TiC (100) surface: A density functional theory study
2024, Surface Science
It is important to study the adsorption behavior of Cl₂ molecules on the TiC surface and the formation and transfer of reaction products to understand and to regulate the low-temperature chlorination reaction process of carbonized titanium-bearing slag. Based on the first-principles ab initio calculation method of density functional theory (DFT), the adsorption models of Cl₂ molecules on the TiC (100) intact surface and the surface with carbon vacancy are established, and the adsorption structures, electronic properties, differential charge density and partial density of states (PDOS) are calculated and analyzed. The formation process and the optimal formation path of the adsorption reaction product are explored. The investigated results indicate that the Cl atoms in the system bonded to the surface Ti atoms are more stable than the structure formed by bonding to the surface C atoms. The electron flow direction is Ti → C and Ti → Cl. In the reaction of TiC with Cl₂ molecules, the TiCl₃ intermediate is easier to form than the TiCl₂ intermediate. The energy barrier to be overcome to form the TiCl₃ intermediate is lower and the energy to be supplied is easily met by external conditions. TiCl₃ is then further chlorinated to form TiCl₄.
Adhesive and tensile properties of diamond(001)/TiC(111) interfaces: A first-principles investigation
2023, International Journal of Refractory Metals and Hard Materials
Since a nanometer-thick carbide layer will be indispensably produced on diamond to ensure wettability with metallic parts, the interfacial properties of diamond/carbide directly affect the service performance of diamond devices. Herein, first-principles calculations were performed to investigate the interfacial properties and tensile responses of diamond(001)/TiC(111) interfaces. Taking into account Ti- and C-termination of TiC(111), and interfacial stacking of hollow- and top-site, four interface models were established. The results showed that Ti-termination could only be stacked by hollow-site. The analysis of energy and electronic structure suggested that hollow-site or C-termination favored to produce a more stable interface, attributing to stronger interfacial C-C covalent bonds and even the additional ionic attraction from Ti atoms, which enhanced the bonding strength significantly. Furthermore, the tensile simulations indicated cleavage always ignited from Ti-C bonds, of which along the interface for Ti-termination and within the TiC for C-termination. Growing C-terminated TiC could greatly improve interfacial stability, but at the expense of mechanical strength. This owed to the homogenization of C-termination by diamond surface. The results provided an atomic insight to characterize the structure and bonding of diamond/TiC interfaces, laying the foundation for developing high-performance diamond devices.
Microstructure and properties evolution during annealing in low-carbon Nb containing steel with high strength and electrical conductivity: an experimental and theoretical study
2023, Journal of Materials Research and Technology
Based on the experiment and first-principles calculation methods, the evolution of microstructure, mechanical properties and electrical conductivity of low-carbon steel were investigated at various annealing conditions. The results show that with the increase of annealing temperature, the morphology of ferrite matrix grain undergoes a transformation from narrow and long fibrous to, accompanied by the continuous growth in size. The strength of α-fibre texture is reduced continuously while the strength of γ-fibre texture increases evidently. The tensile and conductivity testing results indicate that with the increase of annealing temperature, both the yield strength and tensile strength of the steel decrease, while the elongation exhibits an opposite tendency due to the continuous growth of ferrite grains and dissolution of tertiary cementites. Additionally, the electrical conductivity increases because the reduction in the number of grain boundaries weakens their scattering ability to electronic waves. The first-principles calculation results indicate that with increasing distance to the interface, the segregation energy of Nb atom in ferrite matrix is reduced, as well as the interfacial energy of the structure is also decreased. The interface segregation preference of Nb atoms induces the transfer of charge, which is beneficial to enhance the conductivity of the ferrite matrix.
Unraveling the effects of Cr interface segregation on precipitation mechanism and mechanical properties of MC carbides in high carbon chromium bearing steels
2023, Journal of Materials Research and Technology
This study explored the influence of Cr interfacial segregation on the precipitation mechanism and mechanical properties of MC carbides in high-carbon chromium bearing steels. The precipitation of Cr-doped MC carbides at different concentrations was investigated using microscopic morphological characterization (SEM, EDS and HR-TEM) alongside first principles calculations. The results indicated that both the austenite matrix and MC carbides exhibited, FCC structures, and the following orientation relationships of crystal planes in high-carbon chromium bearing steels were as follows: MC (010)//FCC-Fe (100) and MC (111)//FCC-Fe (111). Initially, Cr atoms adsorbed on the Fe-top site of the MC carbide (010) crystal plane, maintaining a distance of 2.5 Å from the Fe atom. Notably, when the Cr atom doping amount was 0.5, the Cr–Fe metallic bond exhibited a long bond length, large bond angle and low bond strength in the MC transition state (TS), resulting in a reduced, reaction barrier (908.08 kcal/mol), thus promoting the precipitation of MC carbide in bearing steel. However, at a Cr atom doping amount level of 1, the shorter bond length, small bond angle, and higher bonding strength of the Cr–Fe metallic bond in the MC TS, elevated the reaction barrier (49709.72 kcal/mol), inhibiting the precipitation of MC carbide in bearing steel. Additionally, this study quantitatively analyzed the effect of Cr atom content on the brittle plastic properties and hardness of MC carbides. At Cr atom contents of 0.23 and 1, the MC carbide hardness reached a minimum value of 3.0 GPa and a maximum value of 17.1 GPa, respectively. This investigation not only elucidated the atomic scale effects of Cr interfacial segregation on the precipitation mechanism and mechanical properties of MC carbides but also provided new ideas for controlling carbide precipitation in high-carbon chromium bearing steels.

View all citing articles on Scopus

View full text

First-principles study on ferrite/TiC heterogeneous nucleation interface

Abstract

Graphical abstract

Highlights

Introduction

Section snippets

Calculation method

Bulk and surface calculations

Establishment of the interface of ferrite/TiC

Conclusion

Acknowledgments

Mater. Des.

Int. J. Fatigue

Tribol. Int.

J. Alloy Comp.

Appl. Surf. Sci.

Acta Metall.

J. Alloys Comp.

Solid State Commun.

Surf. Sci.

J. Alloy Comp.

Surf. Sci.

Acta Mater.

Surf. Sci.

J. Alloy Comp.

Surf. Sci.

J. Alloy Comp.

Metall. Mater. Trans. A

Surf. Coat. Technol.

Wear