First-principles study on the stability and electronic structure of Mg/ZrB2 interfaces

Abstract

ratio, high stiffness, high damping capacity, good elastic modulus, good castability and unique biodegradability in the physiological environment [1][2][3][4]. However, their applications are limited by the poor high-temperature strength and creep resistance.To improve the strength of magnesium alloy, it is a reliable way to refine the grain size using effective nucleants during the casting process. ZrB 2 nanoparticle are such effective nucleants and they are capable of inducing finer long-period stacking ordered phase (nano-LPSO-layer) formation due to the nano-surface effect and finally resulting in the formation of nanograins in magnesium alloys [5]. Also, it is a suitable way to improve the magnesium alloys' stiffness, elastic modulus and wear resistances by preparing particle reinforced magnesium matrix composites since ceramic particles have high strength, hardness and high-wearing features [6,7]. Compared with SiC and TiC particles, ZrB 2 particle reinforced magnesium-based composites fabricated by a direct melt-mixing method [8] have the best strength [9]. The stress transfers from Mg matrix to ZrB 2 reinforcement through the ZrB 2 /Mg interface, and the micro-hardness, fatigue resistance and friction factor of the composites are directly affected by interface bonding [10,11].Up to now, it is known that for effective heterogeneous nucleants in magnesium melt or effective reinforcements in particle reinforced magnesium matrix composites, the lattice mismatch and the chemical interaction play important roles in the overall interfacial energy [12]. And, the ZrB 2 /Mg interface will seriously influence the nucleating in Mg melt [5] or the strength of the composites [13]. Hence, the main purpose of this work was to investigate the mechanism of interface bonding of Mg/ZrB 2 in atomic level and help to improve the mechanical properties of the material.First-principles calculation is a powerful method to provide fundamental information at atomic or electronic level. Generally, (001) plane is a stable low index plane for

Structure prediction of epitaxial inorganic interfaces by lattice and surface matching with Ogre

“…51,52 To achieve the required accuracy, ab initio density functional theory (DFT) can be utilized to calculate the interface energies. [53][54][55][56] However, the increase in accuracy entails an increase in computational cost. Owing to quantum size effects, a large number of layers of each material must be included in the interface model to converge its properties.…”

A First-Principle Study of Interactions between Magnesium and Metal-Atom-Doped Graphene

“…Therefore, the interface properties of the intrinsic graphene/Mg and four-doped graphene/Mg were calculated based on the interactions of magnesium atom with intrinsic and doped graphene. In the study of magnesium, the Mg(001) surface can be used as the preferred surface of interface structure [ 30 , 31 ]. As shown in Figure 6 , the intrinsic interface model includes five layers of atoms, one layer of graphene (4 × 4) supercell (32 atoms), and four layers of Mg(001)−(3 × 3) supercell (36 atoms).…”

Modeling Interfacial Evolutions at Atomistic Scale in the Process of Titanium Oxide Inducing Ferrite Nucleation in Steels

“…The adhesion work (W ad ) can be used to analyze the mechanical properties and chemical bonding strength of an interface, and a larger W ad value represents a more stable interface. W ad is calculated by the following equation 57,58…”