Effect of TiC Particles Addition on Tribological Behavior of Ductile Iron

In order to improve the wear resistance of ductile iron, different contents of TiC particles are added into ductile iron used lost-foam casting and the tribological behavior of ductile iron is studied through a ball-on-disk sliding test. It is found that with the increase of TiC content, the pearlite content gradually increases, which is attributed to TiC promoting the heterogeneous nucleation of cementite and increasing cooling rate of the melt. The increase of pearlite content and the second-phase strengthening caused by TiC improve the hardness and tensile strength of ductile iron. Ductile iron has the best tensile strength (498 MPa) and hardness (168 HV1) with a TiC content of 1 wt.%. The wear resistance also increases with increasing TiC content. The wear volume is reduced from 0.14 to 0.03 mm(3), and the main wear mechanism changes from adhesive wear to abrasive wear. The oxide layer produced by frictional heat on the worn surface and the hardened layer produced by strain hardening on the subsurface further improve the wear resistance. Therefore, the wear resistance of ductile iron is affected by the changes of microstructure before and after wear.