2016 Volume 61 Issue 1 Pages 50-58
We examined the friction properties of the nanostripe structures under dry conditions. The nanostripe structure had multilayer film consisting of soft metal (Au or Ag) and hard metal (Cr) that was deposited on a micron scale slope array on a Si substrate.The thickness of each film was ranged from approximately 100 nm to 200 nm. We measured the friction force on the Au-Cr and Ag-Cr nanostripe structures by rubbing with six kinds of slider (Mo/Ni/Ti pin, SUJ2/Al2O3/Si3N4 ball) using a reciprocating friction tester. The Au-Cr and Ag-Cr nanostripe structures showed stable friction coefficients of about 0.3 in air and between 0.2 and 0.3 in a vacuum (2×10-4 Pa), respectively. When the Ag-Cr nanostripe was rubbed with a Si3N4 ball along parallel to the stripe pattern, it needed more reciprocating motions to stabilize the friction coefficient than the orthogonal direction. Optical microscope observations and EDX (energy dispersive X-ray spectroscopy) analysis showed that soft metal (Au and Ag) film formed on the wear track.
