Study on microstructure and its formation mechanism of Fep/Cu composite coatings produced by laser cladding

Using a 2kW CO2 laser to irradiate the mixture of Cu and Al (5% in weight fraction) powders on Q235 mild steel substrate the composite coatings of Fe/Cu has been successfully produced.The microstructure observations with SEM show that the spherical particles exist in the cladding layer and have regular distribution and are proved to be Fe rich phase particles.These particles have the important effect on the mechanical and electrical magnetic performances of the cladding layer.This paper points out that the formation procedure of the particles has the relation with the fogging process of metal and formulates an expression to calculate the diameter of the particles.