Effect of interlayer interfaces enriched with multi-walled carbon nanotubes network on microstructure and mechanical properties of carbide-based composite coatings

Abstract

In this paper, a WC-20Cr3C2-7Ni/multi-walled carbon nanotubes (MWCNTs)-Ni composite powder with a core-shell structure was prepared by surface modification and electroless nickel plating. After high-velocity oxy-fuel (HVOF) spraying, MWCNTs enriched in the shell and reinforced the interlayer interface of the composite coating. The addition of 0.2 wt% MWCNTs increased the reduced modulus and energy dissipation capacity of the composite coating by 12.6 % and 25.0%, respectively. The HRTEM results showed that MWCNTs formed a network structure at the interface. During the deformation process, stress was effectively transferred to network MWCNTs due to the strong metallurgical bond between MWCNTs and the binder phase. It allowed MWCNTs to absorb more energy and promoted stress to be transferred to the interior along the interlayer interface. The influence of MWCNTs on the elastic deformation process of the coatings was analyzed by numerical simulation.