Fe-based coatings with high V and Cr content were obtained by laser cladding using Fe-based powder with different Cr3C2 and FeV50 content. The results showed that Fe-based coatings were uniform and dense. The constituent phases were mainly composed of α-Fe solid solution with the increase of Cr3C2 and FeV50, γ-Fe and V8C7 phases were achieved. The microstructure of the coatings exhibited a typi...

The interconnected porosity of the Cr3C2–NiCr coatings obtained by high-velocity oxy fuel spraying is detrimental in corrosion and wear resistance applications. Laser treatments allow sealing of their surfaces through melting and resolidification of a thin superficial layer. A Nd:YAG laser beam was used to irradiate Cr3C2–NiCr coatings either in the continuous wave mode or at different repetiti...

The thermodynamic stability of onion-like carbon (OLC) nanostructures with respect to highly oriented pyrolytic graphite (HOPG) was determined in the interval 765-1030 K by the electromotive force (emf) measurements of solid electrolyte galvanic cell: (Low) Pt|Cr3C2,CrF2,OLC|CaF2s.c.|Cr3C2,CrF2,HOPG|Pt (High). The free energy change of transformation HOPG = OLC was found positive below 920.6 K ...

Thermally sprayed cermet coatings are adequate solutions to improve cavitation and wear resistance of hydraulic turbines made stainless steel (SS), especially in rivers with a high sediment load, such as the Madeira River Brazil. However, some cermets easily dissolved river water, leading premature failure coating costly maintenance. Moreover, galvanic corrosion induced by coupling SS can accel...

The item deals with the possibilities of utilization HVOF coatings in thermal cyclic loading conditions. There were evaluated three types of coatings based on WC-Co, WC-Co-Cr and Cr3C2-25NiCr. The quality of coatings was evaluated in terms of their adhesion as sprayed and also during the cyclic thermal loading, EDX analysis and evaluation of microhardness. Construction and structure of coatings...

As a main part of hydraulic cylinder, the piston rod is used in tough surrounding and corrosive condition; consequently a high quality protecting layer is essential. Currently EHC, electroplating hard chromium (hard chrome) is a widespread method for piston rod due to powerful performance and low cost. Unfortunately the plating process contains hexavalent chromium (Cr) which is toxic and carcin...

Graphene nano platelets (GNP) have several attractive properties, including excellent lubricity that can be used to develop wear-resistant coatings. Thermally sprayed chromium carbide–nickel (Cr3C2–NiCr) coatings are widely employed impart wear resistance engineering components. This work attempts improve the of high velocity air fuel (HVAF) Cr3C2–NiCr by incorporating GNP using a hybrid approa...

In this study, a Cr3C2-NiCr cermet cladding layer was prepared on the surface of Q235 steel via high-speed laser method. The effects power, scanning speed, and overlap rate microstructure, quality, interfacial elements diffusion Cr3C2-NiCr/Q235 were studied. results show that there an obvious transition at interface steel, indicating had adequate metallurgical bond with matrix. Fe, Cr, Ni diffu...