Coated powder particles composed of a ceramic core and a metallic coating are being considered for plasma spray applications. The goal of using these powders is to produce particulate-reinforced metal-matrix composite coatings. In this work, the feasibility of plasma spray processing in producing these composite coatings is evaluated. A numerical model is presented to analyze the in-flight ther...

In this paper, the authors present an experimental study of roughness characteristics of electroless Ni-B coatings and optimization of the coating process parameters based on L27 Taguchi orthogonal design. Three coating process parameters are considered viz. bath temperature, reducing agent concentration, and nickel source concentration. It is observed that concentration of reducing agent toget...

Electroless composite coatings used for achieving of high hardness, lubrication properties, non-stick surface, abrasive coating applications that by impregnation of soft and hard particles into Ni matrix. Electroless Nickel-phosphorous coatings properties and performance is greatly affected by the amount of phosphorus in them. The phosphor in this coating usually varies from 1 to 13 percent. In...

Modern gas turbine hot sections need to be protected from elevated temperature and damaging environments. This protection starts as a typically two layer coating system, the base layer or bond coat (BC) acts as a corrosion barrier and a kind of buffer for the thermal mismatch between the base material and the second top thermally protective layer or Thermal Barrier Coating (TBC). The BC is norm...

The effect of an electroless Ni-Cu-P coating on the fatigue behavior of quenched and tempered CK45 steel has been investigated. The fatigue tests under rotating bending conditions have been conducted in three different conditions of uncoated, as-deposited and shot peened prior to the coating deposition. The results indicate that plating of the base steel leads to a fatigue life reduction. The d...

Graphene can be synthesized from polyacrylonitrile (PAN) polymer through pyrolysis. A metal catalyst such as nickel (Ni) is required for the conversion of the polymer to graphene. The metal catalysts can be placed either atop or underneath the polymer precursor. We observed that spatially non-uniform and disconnected graphene was fabricated when PAN film coated with a Ni layer was pyrolyzed, re...

Platinum is added to thermal barrier coatings (TBCs) as it is observed empirically to extend their lifetime, but the mechanism by which Pt acts is unknown. Since Pt has been proposed to alter diffusivities in NiAl, a key component of TBCs, we use first-principles quantum mechanics calculations to investigate atomic level diffusion mechanisms. Here, we examine the effect of Pt on five previously...

Electrocatalytic activity for the hydrogen evolution reaction on Ni–Co–LaNi5 composite electrodes prepared by electrochemical codeposition technique was evaluated. The relationship between the current density for hydrogen evolution reaction and the amount of LaNi5 particles in Ni–Co baths is like the well-known “volcano plot”. The Surface morphology and microstructure of Ni–Co–LaNi5 coatings we...