Influence of pulsed plasma treatment on phase composition and hardness of Cr3C2-NiCr coatings

Abstract

In this study, the research results of the influence of pulsed plasma treatment on phase composition, hardness, and roughness of Cr3C2-NiCr coatings are presented. The Cr3C2-NiCr coating was applied to substrate 12Kh18N10T stainless steel by detonation spraying method. To change the physical and mechanical properties of sprayed coating’s surface layers, subsequent pulse-plasma treatment was used. The pulse-plasma treatment leads to changing the roughness of Cr3C2-NiCr coating. The results of mechanical tests showed that after pulsed plasma treatment, the hardness of Cr3C2-NiCr coating is increased. Based on X-ray diffraction analysis, it was found that the hardness increasing of coating is associated with phase transformations on the surface layer, in particular, the formation of the oxide phase and an increase in the number of carbide particles.

The influence of pulse-plasma treatment on the phase composition and hardness of Fe-TiB2-CrB2 coatings

“…The alloy composition (wt.%): Fe-base; Ni 6 ÷ 8; Cr 20.0 ÷ 20.5; Ti 2.4 ÷ 2.5; B 2.5 ÷ 2.6; Al 5.6. The coating is applied by using a multi-chamber detonation unit (MCDU) [12,13], where the powder material is heated and accelerated by the products of detonation combustion of a combustible gas mixture consisting of propane-butane, oxygen, and air. The coating equipment consists (Figure 1) of a multi-chamber detonation unit for spraying-1; a powder feeder-2; a gas console for feeding the combustible mixture-3; a process control system-4; an automated system for moving the detonation device-5.…”

Influence of Spraying Parameters on the Structure and Tribological Properties of Cr3C2-NiCr Detonation Coatings

“…Various spray technologies are used for coating deposition: atmospheric plasma spraying (APS), high velocity oxygen fuel spraying, air-fuel spraying (HVOF, HVAF), and detonation spraying [5][6][7][8]. In the process of coating Cr 3 C 2 -NiCr powder by thermal methods, a change in the chemical composition of the material is observed due to a decrease in the carbide content in the coating due to elastic rebound [9][10][11][12][13][14][15] and due to oxidation [16,17] caused by the presence of oxygen and superheated water vapor in the combustion products [18,19]. During thermal spraying of Cr 3 C 2 -NiCr powder under the infuence of high temperatures (several thousand degrees) and a combustion gaseous oxidizing atmosphere, the higher carbides (Cr 3 C 2 ) are depleted from carbon to lower carbides (Cr 23 C 6 , Cr 7 C 3 ).…”

Structure and properties of multilayer coatings based on CoCrAlY/Al2O3 obtained by detonation spraying

“…This means that a strong and logical relationship must be established between the coating composition and the coating design (the latter can also be understood as the coating structure). The design of the coating usually implies the development of gradient multilayer structures and their combinations [1][2][3][4].…”