Microstructure and Wear Resistance of Cr3C2/ Ni Composite Coating Deposited by Plasma Transferred Arc Surfacing

The nickel-based alloys with different Cr3C2 contents had been deposited by means of a plasma transferred arc (PTA) welding machine.The effects of Cr3C2 on the microstructure and wear resistance of the nickel-based alloy coatings were investigated using various techniques,including optical microscopy,SEM,XRD and dry sand abrasion test (DSAT).The Cr3C2-free nickel-based alloy coating is composed of γ(Ni,Fe),CrB and M7(C,B)3.The composition segregation exist in this coating.The addition of Cr3C2 particles led to the existing of Cr3C2 phase.The dendrites in the Cr3C2-free coating are broken,which led to the refinement of the Cr3C2-modified coatings.The addition of Cr3C2 particles led to the decreasing of the composition segregation till final disappearance.The wear resistance is improved because of the addition of Cr3C2 particles.The wear resistance increase with the increasing of Cr3C2 contents from 0% to 30%.However,further increasing its content led to the decreasing of the wear resistance.