Investigation on the Formation of a Tribofilm in Si 3N 4 Gray Iron Sliding Pair Lubricated with Na 2SiO 3 Inhibited Solution

During the friction and wear test at various sliding distances, Si 3N 4 worn surface changed from rough to smooth gradually. At the same time, a tribofilm formed on the worn surface of gray iron and experienced repeated absorption and spalling process.The tribofilm on the worn surface of gray iron became smooth as well.The sliding pair of ultrasmooth Si 3N 4 against smooth gray iron under lubrication of Na 2SiO 3 H 2O showed very low friction coefficient and wear.