Interfacial bonding properties between cobalt-based plasma cladding layer and substrate under tensile conditions

Publication date: 5 June 2017
Source:Materials & Design, Volume 123
Author(s): Yang Li, Xiufang Cui, Guo Jin, Zhaobing Cai, Na Tan, Bingwen Lu, Zonghong Gao
Bonding strength is critical to the service life of components in the surface engineering field. To identify the interfacial bonding behavior of metallurgical coating and substrate, micro-plasma cladding technique was used to fabricate cobalt-based metallurgical coating, meanwhile niobium and cerium oxide as reinforced particles were added to the composite coating. The elastic modulus of coating and substrate were measured to assess the matching degree of elastic coefficient between coating and substrate. In addition, the bonding properties of coating and substrate were tested. Result, the microstructure was refined by the addition of niobium and cerium oxide. The composite coating mainly consisted of γ-Co, Cr23C6, M7C3, Ni2Si and NbC. Interface is face-centered cubic structure and the main elements are iron and cobalt near the interface. Tensile and elastic modulus tests demonstrate an excellent match between the coating and substrate. With the addition of niobium and cerium oxide alone or in combination, the tensile performance was improved significantly. The bonding strength of the coating and substrate is superior to that of the coating itself. The fracture occurred in the interface between the two coatings instead of interior of single plasma cladding layer.

Graphical abstract

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