Adhesion, Friction, and Wear in Low-Pressure and Vacuum Environments

Abstract

This article discusses the adhesion behavior of materials in low-pressure and vacuum environments and provides a schematic illustration of an apparatus for measuring adhesion and friction in ultrahigh vacuum. It describes the effects of low-oxygen pressures and vacuum environments on adhesion and friction, as well as the effects of defined exposure to oxygen on friction. The article discusses the wear of various metals in contact with ceramics, and alloying element effects on friction, wear, and transfer of materials. It also describes studies that characterize the contributions of surface contamination and chemical changes to tribology in low-pressure and vacuum environments.

Microstructural and interface properties of aluminium alloy coatings on alumina applied by friction surfacing

“…Experiments conducted by Budgett, 8 bringing two metal surfaces in close contact in vacuum, refute this theory concluding that molecular attraction is the main driving force for adhesion. This is also confirmed for ceramic–metal interfaces in a recent publication by Miyoshi and Abel 9 stating that when a clean metal is brought into contact with a clean ceramic surface in ultrahigh vacuum, strong bonds between the two materials form. Popov, 10 Lipkin et al 11 and Deng et al 12 try to quantify the bonding mechanisms in metal–ceramic systems and come to the conclusion that as the interface surfaces may be in very close proximity van der Waals forces could come into play, so contributing to metal–ceramic adhesion.…”

Hyperloop Communications: Challenges, Advances, and Approaches

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