Study on Formation Mechanism about the Cr3C2-NiCr/NiAl Coating of CuCo2Be Alloy by Plasma Spraying

Cr3C2-NiCr/NiAl coating on the CuCo2Be alloy was prepared by plasma spraying. The formation mechanism, phase composition in the Cr3C2-NiCr/NiAl coating and the phase characteristics were analyzed by DTA, XRD, SEM, EDS etc. The DTA analysis shows that in thermal spray process, Ni2Al3, NiAl3, NiAl phase may be generated for the exothermic reaction. SEM, EDS analysis results showed that the coating displays an obviously layered structure and nickel-aluminum compounds exhibit a angular. XRD analysis shows that the compounds of the coating conformed exhibit different changes and types in the different forming stages and time. The phase formation at the interface and the distribution of elements were investigated by XRD, EDS, it is shown that a certain element diffusion appears in the boundary, So the interface has the micro-metallurgical bonding.