Nanotribology, nanomechanics and nanomaterials characterization

Abstract

Nanotribology and nanomechanics studies are needed to develop fundamental understanding of interfacial phenomena on a small scale and to study interfacial phenomena in magnetic storage devices, nanotechnology and other applications. Friction and wear of lightly loaded micro/nanocomponents are highly dependent on the surface interactions (a few atomic layers). These structures are generally coated with molecularly thin films. Nanotribology and nanomechanics studies are also valuable in the fundamental understanding of interfacial phenomena in macrostructures and provide a bridge between science and engineering. An atomic force microscope (AFM) tip is used to simulate a single-asperity contact with a solid or lubricated surface. AFMs are used to study the various tribological phenomena that include surface roughness, adhesion, friction, scratching, wear and boundary lubrication. In situ surface characterization of local deformation of materials and thin coatings can be carried out using a tensile stage inside an AFM. Mechanical properties such as hardness, Young's modulus of elasticity and creep/relaxation behaviour can be determined on micro-to picoscales using a depth-sensing indentation system in an AFM.

Mecanismos de desgaste derivados de aditivos cerâmicos em lubrificantes fuel economy

“…Os mecanismos de deslizamento envolvem movimento de grande quantidade de discordâncias, que são responsáveis pela deformação plástica na superfície de contato. As discordâncias geradas são armazenadas no corpo e propagam-se com o carregamento 11 . O movimento relativo também pode resultar no desgaste corrosivo com a degradação de uma camada superficial do material devido às reações advindas do meio.…”

Novel method for in-situ and simultaneous nanofriction and nanowear characterization of materials

“…We don't take the full wear track to avoid "border effects" due to the accumulation of material as a result of the wear. Also, we take the mean value in trace and retrace to eliminate any effect due to an inclination of the surface, in the same way that is done for AFMs 4 . The coefficient of friction µ is then obtained considering that the friction force is directly…”

“…The first experiments have allowed the researchers to characterize ultra-thin diamond-like carbon (DLC) coatings deposited on hard disks and magnetic recording heads, and also to carry out basic research on the origin of friction and wear at the atomic and molecular scale. Friction characterization with AFM has also been done in some cases where a careful calibration of the instrument allowed the recording of static and dynamic friction over dry and lubricated surfaces 4 .…”

Protection of specimens against friction and wear using titanium-based multicomponent nanocomposite coatings: A review

“…The significance of studying single contacts between asperities in research into fundamental nano and micromechani cal, as well as micro and nanotribological, properties of surfaces and interfaces has long been recognized [2][3][4][5][6].…”

“…Nanomaterials and nanotechnolo gies have become a priority trend in materials science in recent years [1,2].…”