Spatio-temporal structure in wax-oil gel scraping at a soft tribological contact

The wax-deposit scraping process has been observed with a soft tribology instrument. Experimental results show that the formation of deposit scraping-chip is due to rubber tribology of elastomer disc. A major change occurs in contact front when the solid-wax content increases with rapidly changing the conformity local to the sliding soft surfaces. When the scraping speed is a much larger value, the accumulation and chip-formation process of wax-deposit occurs quickly. The scraping-chip instability arises from a competition between the adhesion and scraping forces. The behaviors of the residual phenomenon depend on the inlet aggregation of soft lubrication.