Effect of Irradiation with DC Plasma Jet on the Structure Phase Compositions and Properties of Powder Ni and Co – based Coatings

Abstract

This paper presents new results of transmission electron microscopy (TEM), scanning electron microscopy (SEM), Xray diffraction (XRD) and atomic force microscopy (AFM) investigation of the structure-phase compositions of coatings on the base of Ni and Co deposited by plasma-detonation on steel substrates after their modification by DC plasma jet irradiation. The phase structures and morphology of precipitation of strengthening phases from solid solution are defined. The irradiation of the coatings leads to the evolution of the structural-phase state of coatings: an increase in the size of the diffusion zone between the coating and the substrate, an increase in the volume fraction of hardening intermetallic phases, the formation of sufficiently homogeneous fine-grained structure in the irradiated coatings and, consequently, a significant increase of hardness, corrosion and wear resistance of modified coatings. There is a mutual penetration of the substrate main element Fe in the coating and base coating elements (Ni and Co correspondingly) into the substrate as a result of the coating treatment by a pulse DC plasma jet.

Plasma-Assisted Automated Precision Deposition of Powder Coating Multifunctional Systems

“…In order to form the desired nanostructures in microplasma coatings there were used the same powders as for the plasma detonation coatings where these nanostructures were observed previously [8][9][10][11].…”

“…These layers are also characterized by high hardness [8,9]. Our previous papers [10,11] dealt with the selection of relevant * corresponding author; e-mail: dalontseva@mail.ru components for developing multifunctional powder coating systems and appropriate trajectory of the plasma source and processing modes. This was based on mathematical modelling of the optimized condition determined by our initial experimentation [12,13].…”

Developing a New Resource and Energy Saving Technology of Precision Application of Powder Coating Multifunctional Systems

“…The authors of this work have had successful experience of plasma jet treatment of powder coatings. Their previous works in deposition by plasma detonation techniques on steel substrates have been reported in detail [7][8][9]. The selection of plasma irradiation processing modes (namely, the power density of the plasma jet on the coating surface, and the velocity of the plasma source) is based on the analysis the authors have done in their past works [10,11].…”

“…It provides the opportunity of using the same source for the coating deposition, and at the same time to reduce power consumption, needed for additional treatment. The results of additional processing of plasma-detonation coatings by the direct current (DC) plasma jet are discussed in our works [7,9].…”