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Among them, plasma transferred wire arc (PTWA) thermal spraying coating is becoming popular. Plasma electrolytic oxidation (PEO) coating is also proposed for increasing the wear resistance of aluminum alloy and reducing the friction between the cylinder and piston. ...In this work, a PEO coating with a thickness of ∼20 μm was prepared, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coating at oil lubricant conditions. Different surface roughness of the coating and a large range of the sliding speeds were employed for the tests. ...In this work, a PEO coating with a thickness of ∼20 μm was prepared, and a high speed pin-on-disc tribometer was used to study the tribological behavior of the coating at oil lubricant conditions.

Plasma electrolytic oxidation (PEO) coating is considered as a hard ceramic coating which can provide a dimpled surface for oil retention to bear the wear and reduce the friction from sliding piston rings. ...Five different lubricating oils and two different loads were applied to do the tribotests and the COFs of a PEO coating were studied. The results show that the PEO coating indeed had a lower COF in a lower viscosity lubricating oil, and a smaller load was beneficial to form the mixed and hydrodynamic lubricating regimes earlier. ...When tested with a very high viscosity of oil, the counterpart material had a significantly less wear, which may indicate that such kind of oil would provide a piston ring with a better protection against the ceramic coating. Thus, a proper selection of lubricating oil for PEO coating would be a decisive factor for balance between reducing friction loss and piston ring wear in an IC engine.

Surface coating on the gray cast iron rotor represents a trending approach dealing with the problems. In this research, a new plasma electrolytic aluminating (PEA) process was used for preparing an alumina-based ceramic coating with metallurgical bonding to the gray cast iron. ...In this research, a new plasma electrolytic aluminating (PEA) process was used for preparing an alumina-based ceramic coating with metallurgical bonding to the gray cast iron. Three different types of brake pads (ceramic, semi-metallic and non asbestos organic (NAO)) were used for tribotests. ...Performances of PEA coatings vs. different brake pad materials were comparatively investigated with respect to their coefficients of friction (COFs) and wear.

In this paper, a plasma electrolytic oxidation (PEO) process was used to produce ceramic oxide coatings on aluminized UHSS and Mg with intention to further improve their corrosion resistances. ...Galvanic corrosion of the aluminized UHSS and magnesium alloy coupling with and without PEO coatings was studied by a zero resistance ammeter (ZRA) test. It was found that the heating-cooling process simulating the hot stamping would reduce anti-corrosion properties of aluminized UHSS due to the outward iron diffusion. ...The PEO coating could reduce corrosion current and increase corrosion potential of aluminized UHSS. A denser PEO coating, usually produced using a bipolar current processing mode and thus showing a higher polarization corrosion resistance, was not always good for the galvanic corrosion prevention of the steel and Mg coupling.

Based on the research, this article briefly discusses employing plasma electrolytic aluminating to coat 52100 alloy steel samples, an eco-friendly and high-efficiency coating process. Coating experiments were conducted over different coating periods to determine the most appropriate thin film for 52100 alloy steel samples. ...Alumina coatings are suitable for insulating the 52100 alloy steel samples because alumina coatings provide excellent insulation, hardness, and corrosion resistance, among other characteristics. ...Longer treatment period resulted in thicker coating layers, but a rougher surface. The results indicated that extending the coating period increased the insulating characteristics of the ceramic coating on 52100 alloy steel samples.

Comparing with the PEO Alumina coatings, the PEA Alumina coating has much lower Coefficient of Friction (COF) and less wear. The microstructure, chemical composition and phase composition of this coating were investigated with Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDX) and X-Ray Diffraction (XRD), respectively. ...Since the PEA coating can also be applied onto steel materials, the coating technology can be used to protect the hinges of doors and other joint parts from frequent wear and corrosion issues. ...Alumina (Al2O3) thin film coatings are applied on Al alloys using Plasma Electrolytic Oxidation (PEO) method to reduce the wear and corrosion problems.

However, mentioned surface coating processes increase the cost of brake rotors and there is a need to search for cost-effective coating processes. In this research, a new Al2O3-Ni composite coating was proposed for preparation of a commercial cast iron brake rotor using plasma electrolytic aluminating (PEA) followed by electroless nickel plating (ENP) processes. ...The added nickel was to fit in the intrinsic pores of PEA coating and reached to the coating top surface. The brake rotor with the corrosion-resistant PEA-ENP coating was tested with modified SAE Brake Dynamometer Standards J2522. ...However, mentioned surface coating processes increase the cost of brake rotors and there is a need to search for cost-effective coating processes.

A plasma electrolytic oxidation (PEO) technique had also been proposed to produce an oxide coating on aluminum cylinder bore. The oxide coating can have a low coefficient of friction (COF) and minimum wear shown in the lab tests. ...The smoother of the coating surface, the less wear of counterface pin. A proper combination of coating surface roughness and sliding velocity could provide a significant lower COF and less wear. ...To overcome the aluminum alloys' poor wear resistance, cast iron liners and thermal spraying coatings were used as cylinder bore materials for wear protection. A plasma electrolytic oxidation (PEO) technique had also been proposed to produce an oxide coating on aluminum cylinder bore.

A chromium nitride (CrN) coating with plasma nitriding case hardened layer on a die material (duplex treatment) is found to offer good wear and galling resistances. The coating failure initiates from fatigue cracking on the coating surface due to cyclic sliding frictions. ...Stamping of AHSS with conventional die materials and surface coatings, however, results in frequent die failures and undesired panel surface finish. A chromium nitride (CrN) coating with plasma nitriding case hardened layer on a die material (duplex treatment) is found to offer good wear and galling resistances. ...A chromium nitride (CrN) coating with plasma nitriding case hardened layer on a die material (duplex treatment) is found to offer good wear and galling resistances.

In order to optimize the PEO process, orthogonal experiments were conducted to investigate the effect of PEO process parameters on the wear properties of PEO coatings. The PEO coatings showed a much better wear resistance, as well as a smaller friction coefficient, than the AJ62 substrate. ...In this paper, Plasma Electrolytic Oxidation (PEO) process was used to produce oxide coatings on AJ62 Mg alloy to provide wear and corrosion protection. In order to optimize the PEO process, orthogonal experiments were conducted to investigate the effect of PEO process parameters on the wear properties of PEO coatings. ...Applying PEO coating on Mg can effectively prevent the galvanic corrosion attack to Mg. Due to the small thickness of the PEO coating, the thermal conductivity of Mg would not be appreciably affected.

Laser cladding is a novel process of surface coating, and researchers in both academia and industry are developing additive manufacturing solutions for large, metallic components.

We are witnessing a rapid and ongoing expansion of nanoscience, driven by potential applications in advanced materials and nanotechnology. There is a race to develop techniques that may allow controlling the size, shape of nanostructures that can allow the tuning of their optical and electronic properties. Plasmonics is a field that encompasses and profits from the optical enhancement in nanostructures that support plasmon excitations. One of these new techniques is surface-enhanced Raman scattering (SERS), commonly used for nanostructure characterization. In the present report, we present a theoretical model for plasmon excitation and electric field enhancement that help to provide an explanation for the special features observed in experimental SERS. Two sets of experimental results are discussed illustrating the make out of the signature of the plasmonics producing the optical enhancement.