Microstructure and Mechanical Properties of in Situ WC Particles Reinforced Iron-Based Composite Coating

摘要

A kind of centrifugal casting plus in situ techniques of fabricating iron-based composite coating reinforced by tungsten carbide (WC) particles was developed. The experimental results show that the reinforcing particles were generated by reaction between dissolved tungten wires and carbon from gray cast iron molten. The composite coating mainly consists of primary WC carbides, some fine secondly WC carbides as the reinforcing phase and pearlite accompanied by negligible graphite flakes as the matrix. Compared with the unreinforced gray cast iron, the in situ synthesized WC particles can enhance the ultimate tensile strength and decrease elongation rate of the composite coating. Fracture morphology reveals that fracture mode of composite coating is brittle and ductile mixed fractures, the fracture mechanism of the composite is not only related with the introduction of reinforcement but also with the reduction of graphite flakes in the matrix