Tribological behaviors and mechanism of as-cast QT700-8 ductile iron with high strength and toughness

This work investigated the effects of normal load, sliding speed and ambient temperature on the tribological behaviors and mechanism of as-cast QT700–8 ductile irons. A high-temperature friction and wear tester is used to study the sliding dry friction and wear behaviors. The coefficients of friction (COFs) were in positive correlation with ambient temperature, while it is negative correlated to normal load. The maximum wear rates corresponding to normal load, sliding speed and ambient temperature were 8.9 × 10−6 mm3/(N * m), 11.34 × 10−6 mm3/(N * m) and 30.83 × 10−6 mm3/(N * m), showing a good wear resistance. Moreover, the main tribological mechanism was abrasive wear accompanied by oxidative wear. According to friction molecular dynamics simulations, dislocations become densely distributed around the friction contact during the friction tests.