Tribological properties of silver coatings with laser surface textured nickel as interlayer

The textured nickel coatings with the dimple diameters of about 100 μm were prepared as the transition layer of silver coatings. The tribological properties of silver coating on textured nickel surface were tested by rubbing against Si3N4 ceramic ball from room temperature to 700 °C. The friction coefficient of silver coatings on the textured nickel with the appropriate dimples density is lower and more stable than those on un-textured nickel or textured surface without nickel interlayer. The low friction coefficient (~0.2) can sustain for a long distance at 700 °C. With the dimple density increasing, the friction coefficient decreases firstly and then increases. The textured dimples accommodate the wear particles and store soft lubricant at elevated temperatures.