Effects of C/B₄ C ratio on microstructure and property of Fe-based alloy coatings reinforced with in situ synthesized TiB₂-TiC

The Fe based alloy coatings reinforced with in situ synthesized TiB₂-TiC were prepared on Q235 steel by reactive plasma cladding using Fe901 alloy,Ti,B₄C,and graphite（C） powders as raw materials.The effects of C/B₄C weight percentage ratio（0-1.38） on the microstructure,microhardness,and wet sand abrasion resistance of the coatings were investigated.The results show that the coatings consist of（Fe,Cr） solid solution,TiC,TiB₂,Ti₈C₅,and Fe₃C phases.The decrease of C/B₄C ratio is propitious to the formation of TiB₂ and Ti₈C₅.Increasing the C/B₄C ratio can help to refine the microstructure of the coatings.However,the microhardness of the middle-upper of the coatings and the wet sand abrasion resistance of the coatings degenerate with the increase of C/B₄C ratio.The coating exhibits the best wet sand abrasion resistance at C/B₄C =0 and its average mass loss rate per unit wear distance is 0.001 2%/m.The change of the wet sand abrasion resistance of the coatings with the C/B₄C ratio can be mainly attributed to the combined action of the changes of microhardness and the volume percentage of the ceramic reinforcements containing titanium in the coatings.