Microstructure and mechanical properties of carbon fibers strengthened Ni-based coatings by laser cladding: The effect of carbon fiber contents

Abstract

To study the effect of carbon fibers (CFs) on the microstructure and properties of Nickel based coatings, the carbon fibers reinforced Ni-based composite coatings (CFs/Ni) were fabricated on the surface of Q235 steel by laser cladding (LC). The microstructural and interfacial characteristics between CFs and Ni-based metallic matrix, microhardness and tensile strength of coatings were investigated. The results showed that the CFs with different contents presented the different morphologies and distribution in coatings. When the CFs increased from 0 vol% to 9 vol%, the homogeneity in distribution of CFs in coatings were improved first and then decreased. Especially, the distribution of CFs was the most uniform when the CFs content was 6 vol%. As a result, the average microhardness and ultimate tensile strength of the composite coating reached up to 678 HV0.2 and 608 MPa, respectively, which was about 1.7 and 3.7 times respectively higher than the corresponding one of Ni-based coating without CFs. This can be attributed to the homogeneous distribution of CFs and the metal carbides as well as good bonding of the interface between CFs and matrix.