Quasicrystals, materials with an ordered but not periodic structure, are a unique object for studying the properties of surfaces at the atomic level. Their unusual structure, characterized by the absence of translational symmetry and the presence of long-range orientational order, determines their specific behavior in friction and adhesion processes.
One of the key aspects is the low friction coefficient of quasi-crystalline surfaces. This is due to the formation of incommensurate interfaces when in contact with other materials, which complicates the coordinated sliding of atomic planes. Adhesion, in turn, is determined by the atomic structure of the surface and the distribution of the electron charge. Quasicrystals exhibit relatively low adhesion, which also helps reduce friction.
Atomic force microscopy (AFM) and tribology at the atomic level allow detailed study of friction and adhesion processes on quasi-crystalline surfaces. AFM provides visualization of the atomic structure of the surface and measurement of the interaction forces between the probe and the material. Tribological experiments allow evaluation of the friction coefficient and wear under various loads and sliding speeds.
Theoretical modeling based on molecular dynamics and density functional theory methods allows us to understand the mechanisms of friction and adhesion at the atomic level. These models take into account the features of the atomic structure of quasicrystals, the distribution of the electron charge, and the interaction between atoms of different elements. The modeling results are in good agreement with experimental data and allow us to predict the properties of quasicrystalline surfaces under various operating conditions.
Author: Jung Young Park and P. A. Til
Institute: Department of Metallurgy and Materials Science, Federal University of Minas Gerais, Avenida António Carlos, 6627, Belo Horizonte, Minas Gerais, 31270-901, Brazil