Microstructure and Wear Properties of TiB2 Reinforced Fe-Based Composite Coating

FeNiCrAl-B 4 C and FeNiCrAl-B 4 C-TiB 2 coatings were deposited on Q235 steel substrates by high velocity arc spraying technology for preparation of subsequent application on agricultural machinery tools. The spraying process parameters of FeNiCrAl-B 4 C-TiB 2 coating were optimized by orthogonal test experiment. The microstructure and phases of coatings were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). The wear resistance of the coatings was studied by dry sliding wear test, and the tribological behaviors analyzed. It was found that the two kinds of Fe-based coatings presented a similar layered structure, but FeNiCrAl-B 4 C-TiB 2 coating had a more compact structure with lower porosity of 3.27%. After the addition of TiB 2 powder, hard phases of TiB 2 , TiO 2 , and Fe-Cr formed and significantly increased the hardness of the coating approximately 0.7 times higher than that of FeNiCrAl-B 4 C coating. The wear resistance of the FeNiCrAl-B 4 C-TiB 2 coating was about 1.8 times higher than that of FeNiCrAl-B 4 C coating under the same testing conditions and further investigations showed that the dominant wear mechanism of FeNiCrAl-B 4 C-TiB 2 coating was brittle fracture. The results indicate that wear resistance of the coatings improved by the addition of TiB 2 reinforcement.