Effect of Graphene on the Microstructure and Properties of Laser Cladding Cobalt-Based Coatings

Abstract

For studying the effect of graphene on the microstructure and properties of laser cladding cobalt-based alloy coatings，mixed alloyed Stellite6 powder and graphene were selected as the cladding material，and the composite coatings with the graphene mass fractions of 0.5%～2.0% was prepared on 00Cr13Ni4Mo martensitic stainless steel under the same process parameters.Results showed that a small amount of graphene was burned out during the laser cladding process，and part of the graphene was retained.When the graphene content reached 1.5%，obvious cracks appeared in the coating surface.With the increase of graphene content，the hardness of the coating reached 720 HV.When the graphene content was 0.5%，the wear loss of the coating decreased from 2.31 mg to 1.96 mg，the wear resistance of the coating increased，and the excessive graphene reduced the wear resistance of coatings.When the graphene content was 0.5%～1.0%，the cavitation corrosion loss was about 1/3 of that of the Stellite6 coating，and the cavitation resistance of the coating was improved.When the graphene content exceeded 1.0%，the cavitation corrosion resistance of the as-obtained coating declined significantly due to crack defects.

Keywords

• co-based alloy|cavitation corrosion|laser cladding|graphene