Thin Films, Materials Surface & Interfaces
Giulia F. da Silva; Jorge Conceição Jr.; Daiane T. da Silva; Everton Dos Santos
Abstract
This study investigates the deposition of hydrogenated diamond-like carbon (DLC) films on SAE 1045 alloy samples using a plasma-enhanced chemical vapor deposition (PECVD) system and evaluates their potential as automotive coatings. Copper doping was performed via a hollow copper cathode to examine its ...
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This study investigates the deposition of hydrogenated diamond-like carbon (DLC) films on SAE 1045 alloy samples using a plasma-enhanced chemical vapor deposition (PECVD) system and evaluates their potential as automotive coatings. Copper doping was performed via a hollow copper cathode to examine its effects on the DLC films. The primary focus was to determine the structural properties, color variations, and friction resistance of the coated samples, with the goal of establishing their applicability in the automotive industry. Raman spectroscopy confirmed the successful deposition of DLC films, while energy dispersive X-ray spectroscopy (EDS) analysis demonstrated the variation in copper atom concentrations in the samples based on the sputtering duration during the doping process. The observed color changes in the DLC films correlated with the copper atom concentrations, with the interference phenomenon and refractive index differences between DLC films and copper proposed as the primary factors influencing color variations. Scratch tests were conducted to evaluate the resistance to friction and delamination of the coated materials compared to conventionally painted steel samples. The results indicated that the DLC-coated materials exhibited higher resistance, with an estimated 15% increase in delamination resistance. The enhanced resistance was hypothesized to result from the high hardness of DLC films and the potential accumulation of nanoparticles in the valleys of the sample surface, reducing irregularities.
Thin Films, Materials Surface & Interfaces
Bougoffa M. Seyf Eddine; Sayhia Benchaa
Abstract
The paper examines the influence of initial surface roughness and sliding speed on friction and wear behavior of AA6061 aluminum alloy and brass alloy (CuZn37Pb2) under dry contact using a CSM tribometer. Surface roughness of materials studied were measured using optical profilometer. Rough surfaces ...
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The paper examines the influence of initial surface roughness and sliding speed on friction and wear behavior of AA6061 aluminum alloy and brass alloy (CuZn37Pb2) under dry contact using a CSM tribometer. Surface roughness of materials studied were measured using optical profilometer. Rough surfaces (Ra=0.37 - 1.33 μm) were prepared on two materials: AA6061 and CuZn37Pb2 alloy. Track width, wear rate, and wear loss values were assessed and contrasted with changes in coefficient of friction values at various starting surface roughness and sliding speeds. Experiments are conducted at sliding speed 0.15;0.24;0.35 and 0.48 m/s. wear track diameter 4;6;8;10 mm. Results show that wear loss, wear rate and track width of CuZn37Pb2 and AA6061 increase at high initial surface roughness and speed but the value of friction coefficient decreases. Various SEM analysis of the wear trace and worn surfaces for each alloy at different sliding speed were analysed and compared.
Nanomaterials & Nanotechnology
Giorgos Papadimitropoulos; Angelika Balliou; Dimitris Kouvatsos; Dimitris Davazoglou
Abstract
The gas sensing properties of porous hot-wire MoS2 (hwMoS2) thin films have been studied. The films were deposited on oxidized silicon substrates by heating a molybdenum filament in a vacuum chamber in H2S environment. The samples remain at room temperature during the deposition and the grown films are ...
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The gas sensing properties of porous hot-wire MoS2 (hwMoS2) thin films have been studied. The films were deposited on oxidized silicon substrates by heating a molybdenum filament in a vacuum chamber in H2S environment. The samples remain at room temperature during the deposition and the grown films are amorphous and porous. Reversible changes of the current values in the hwMoS2 films were observed due to the presence or upon removal of chemical gases such as hydrogen (H2) and carbon monoxide (CO). The sensitivity, was dependent on the concentrations of the gases and the temperature of measurement. The response time was found to be comparable to the recovery time and of the order of a few seconds. It is important to note that the surface of the hwMoS2 films was not activated with any catalyst, which is a common practice in most thin films used for gas sensing, rendering our process simpler and cheaper.
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