Influence of the powder mixture composition on the deposition coefficient and the properties of NI+B4C CGDS coatings

Abstract

The cold gas dynamic spray (CGDS) method used to form composite Ni+B₄C coatings from mechanical powder mixture with various content of abrasive components is investigated, and the surface and microstructure of these coatings are considered. An experimental dependence of the deposition coefficient on the abrasive content in the mechanical powder mixture is obtained. The coatings are studied by interference profilometry, optical microscopy, and microindentation methods. The dependence of the bulk and mass B₄C content in the sprayed material on the abrasive content in the sprayed powder mixture is obtained. The bulk B₄C content in the coating c_V ≈ 0.27 is attained. The dependence of the microhardness of composite CGDS coatings on the boron carbide content in them is investigated. The results of this paper demonstrate that the powder mixture composition significantly affects the CGDS coating growth and the properties of these coatings and can be used to control the properties of the CGDS cermet materials.