Investigation of the friction behavior of SiO₂ under dry sliding and lubrication

The friction behavior of SiO₂/GCr 15 in dry air and lubricated with distilled water, 1-butanol, 1-decanol and octanoic acid was investigated by using SRV ball-on-disk test rig and a Kyowa DF·PM one-way reciprocating friction tester. The reactivity between the lubricants and SiO₂ surface was simulated by differential scanning calorimetry. As the results, the order of the friction coefficient under oscillating condition can be ranked as dry air>distilled water>1-butanol>1-decanol≈octanoic acid, and that under one-way reciprocating condition can be ranked as distilled water>1-butanol>1-decanol>dry air≈octanoic acid. The order of the reactivity between the lubricants and SiO₂ surface is distilled water>1-butanol>1-decanol>octanoic acid. Thus the higher the reactivity between the lubricants and SiO₂ surface is, the higher the friction coefficient will be. The characteristics of the tribochemical reaction film play an important role in governing the friction behavior of SiO₂ ceramic.