Adhesion and material transfer between contacting Al and TiN surfaces from first principles

Abstract

A series of density functional theory (DFT) simulations was performed to investigate the approach, contact, and subsequent separation of two atomically flat surfaces consisting of different materials. Aluminum (Al) and titanium nitride (TiN) slabs were chosen as a model system representing a metal-ceramic interface and the interaction between soft and hard materials. The approach and separation were simulated by moving one slab in discrete steps normal to the surfaces allowing for electronic and atomic relaxations after each step. Various configurations were analyzed by considering (001), (011), and (111) surfaces as well as several lateral arrangements of these surfaces at the interface. Several tests were conducted on the computational setup, for example, by changing the system size or using different approximations for the exchange correlation functional. The performed simulations revealed the influences of these aspects on adhesion, equilibrium distance, and material transfer. These interfacial properties depend sensitively on the chosen configuration due to distinct bond situations. Material transfer, in particular, was observed if the absolute value of the adhesion energy for a given configuration is larger than the energy cost to remove surface layers. This result was found to be independent of the employed exchange correlation functional. Furthermore, it was shown that a simple comparison of the surface energies of the slabs is not sufficient to predict the occurrence of material transfer.

c-axis preferential orientation of hydroxyapatite accounts for the high wear resistance of the teeth of black carp (Mylopharyngodon piceus)

“…Figure 4a shows the simulation model, in which a rigid pyramidal probe is initially compressed on a single crystal HAp to depth D p = 2 nm and then displaced horizontally at a constant speed and constant attack angle α (i.e., the angle between the scratching surface of the probe and the horizontal plane). To quantify the extent of abrasion, the amount of debris was computed by counting the number of Ca atoms scratched away from the bulk HAp 14 15 16 17 18 19 20 21 . A Ca atom is counted as debris if its displacement exceeds a critical value of 1.0 nm, which is roughly the HAp lattice constant or the cutoff distance of the force field 14 15 16 17 18 .…”

A simple descriptor for energetics at fcc-bcc metal interfaces

“…The study of metal-metal interfaces is crucial for many industrial processes and technological applications [1][2][3], including growth modes in thin films [4,5], catalysis [6], as well as many experimental techniques used in nanotechnology such as those involving metallic tips on metal surfaces [7]. Theoretical support in designing metallic interfaces is essential as it can provide information that is extremely difficult to extract experimentally.…”

“…These energies are not directly accessible experimentally. Thorough studies have been performed at the level of first-principles calculations on selected solid-solid interfaces, focusing on various aspects such as the film thickness [4], orientation [7], magnetoresistance [11], magnetic anisotropy [12] ferromagnetic moments [13], as well as electronic [14][15][16][17], mechanical [18][19][20][21], and thermodynamic [22][23][24][25][26] properties. Notwithstanding Email address: linda.zotti@uam.es (Linda A. Zotti 1,2 ) the detailed nature of these analyses, they were quite often mostly focused on a very few materials.…”

Effect of Active Al on the Microstructure and Mechanical Properties of a Mo/Sn-Based Solder Interface: First-Principles Calculation and Experimental Study

“…Then the structure experiences relaxation. 22 The UBER results for the Mo(110)/Sn(001) interface are listed in Fig. 3 and Table II; the interface with bridge site was found to have the largest W ad of 1.80 J/m 2 .…”