Contrasting roles of speed on wear of soda lime silica glass in dry and humid air

It is well-known that the sliding contact damage of glass materials is very sensitive to the presence of water, but the detailed mechanisms remain elusive. In this work, the effects of water and speed on wear behaviors of soda lime silica (SLS) glass are investigated upon a ball-on-flat reciprocating tribometer in dry and humid air. When water molecules are present at the sliding interfaces in humid air, the wear volume of SLS glass decreases with the increase in sliding speed from 0.25 mm/s to 8 mm/s, which is believed to be originated from the suppressed tribochemical reactions involving water molecules at high speed conditions, therein the wear volume of SLS glass decreases to similar to 6 times. However, when water molecules are absent at the sliding interfaces in dry air, the wear volume of SLS glass increases to similar to 12.5 times when the sliding speed increases from 0.25 mm/s to 8 mm/s. Analyses suggest that the wear of SLS glass in dry air is dominated by the adhesive wear and brittle exfoliation, which can be facilitated by the friction-induced temperature rise and surface cracking at high speed conditions. Our results indicate that the sliding speed can either promote or suppress the wear of SLS glass, depending on the presence of water molecules at the sliding interfaces. These results may provide a deep understanding on the effects of water and speed on the material damage of oxide glass materials during its manufacturing and operation processes.