Research on Abrasive Wear Behaviour of Laser Cladding Layers With Aluminum Bronze Powders

The paper presents the wear behaviour on rotating disk with abrasive paper of laser cladding layers with aluminum bronze powders compared with steel samples and aluminum bronze classically quenched. The hardness and wear mass variation were monitored

Studies and Researches on Obtaining Electrochemical Composite Coatings in Nickel - Ni / Kaolin Matrix

The paper presents the electrochemical obtaining of nickel matrix composite coatings using kaolin particles as dispersed phases. Watts electrolytes were used, with a pH = 4.5 current densities of 6, 9, 12 A/dm2 , a dispersed phase concentration of 20 g/L, shaking speeds of 500, 700 and 900 rpm, deposition time of 60 minutes. Their characterization has been achieved both from a microstructural point of view and from the point of view of layer thickness, microhardness and behaviour in salt mist corrosion. The presence of dispersed phase particles, which acted as nucleation centres, led to the reduction of the nickel crystallites, which further decreased the roughness of the coatings while increasing hardness. By correlating the current density with the rate of stirring, respectively the increase their, thicker layers were obtained

Research on the Coverage of Cold-Rolled Flat Products with Film-Forming Materials

The paper aims to characterize film-forming materials from the microstructural, mechanical point of view for the assessment of the elasticity and flexibility of films, and from the chemical point of view, to determine their resistance to various chemicals, distilled water, 3% hydrochloric acid and 3% sodium hydroxide and their behaviour at corrosion in saline mist. It aims to develop a coating technology with film-forming materials for protection against corrosion

Researches Regarding Structural Changes due to nickel Microlalloying of Hot Galvanizing Baths

This work offers a synthesis of researches performed in laboratory and regards the nickel microalloying of hot galvanizing baths. Experiments followed the structural changes of both hot galvanizing bath and deposed layer with effect on layer properties. Characterization of deposed layer and nickel microalloying of galvanizing bath performed by spectral chemical analysis, optical microscopy and X ray diffraction emphasized the structural constituents nature as well as changes shown up depending on nickel concentration of galvanizing bath. Correlation diagrams between deposed layer thickness and structural constituents were also made. Experimental results emphasized a close interdependence between nickel concentration and microstructure. This allowed to settle the optimal nickel concentration required by galvanizing bath microalloying with maximum effect upon hot galvanizing coating properties

Research on the Corrosion Behavior of the Stainless-Steel Thin Films Coated by PVD Method, Magnetron Assisted

The paper follows the corrosion behaviour of X10CrNi 18-8 stainless steel thin films coated by PVD method, magnetron assisted, on glass and copper substrates. It was found that with the increase of the coating time increases of the thickness of the coated layer which leads to the decrease of the corrosion rate. The surface condition can influence the corrosion behaviour through the existing defects and the size of the roughness. Coating uniformity, respectively corrosion, changes with the distance from the axis of symmetry of the magnetron

Laser Deposition of Bronze Aluminum on Steel Support

In order to rise the wear and corrosion resistance of 0.45% C superficial steel layers, a multilayer coating was tested by injection of powder with 88.3% Cu; 9.5% Al; 2.2% Fe in melted bath by CO2 continuous wave laser. Layers made by different laser conditions were characterized by macro and microstructure analysis, phase quality analysis, by X ray diffractometry and microhardness analysis. Research was carried out regarding the importance of nickel alloy intermediary layer for the rising of cladding quality

CuO Films Obtained by Oxidation of Cu Layers Deposited by the PVD Process - Magnetron Sputtering

The experimental research carried out and described in this paper aimed to obtain thin films from copper oxides and their characterization from the structural point of view and the optical and electrical properties. To obtain the copper films, a PVD spray deposition system was used, consisting of a vacuum chamber with a capacity of 2 liters, a planar magnetron with ferrite magnets (40x22x9) neodymium (15x8), a vacuum pump with sliding blades, a variable source of direct current of voltage 100 - 600 volts. The atmosphere used for plasma maintenance during deposition was argon rarefied in a pressure range between 3·10-2 - 8·10-3 mbar. The deposits were made on glass plates. The films thus obtained were subsequently subjected to oxidation at temperatures of 200, 300 and 450 °C. It was found that the transparency of the films increases with the oxidation temperature from 1.464 * 10-4 for 200 ºC to 0.5 for 450 ºC and the surface electrical resistance also increases from 0.984 Ώ for 200 ºC to 3882857,1428 Ώ for 450 ºC. With increasing spray power, transparency and surface strength decrease

Studies and Research on the Corrosion Behavior of Ni-Al2O3 Compound Coatings Obtained by Electrochemical Methods

The undertaken research which is described in this paper aims at the corrosion behaviour of composite coatings in nickel matrix using as dispersed phase technical alumina with dimensions of 5 μm and their characterization from a microstructural point of view. The corrosion resistance in the saline fog of the coatings is influenced by the microstructure, the stresses developed in the layer and the roughness

Study of Heat Treatment Influence on Aluminum - Based Alloy ATN-Si10Cu4

This work presents the experimental results concerning the behavior on heat treatment of on aluminum based alloy. The laboratory level experiments achieved on samples of ATN-Si10Cu4 (4145 series) alloy illustrate the variation of properties depending on the variation of heat treatment technological parameters specific to different heat treatment. We have experimented more variants of heat treatment in order to establish the optimal variant treatment. The samples were characterized by HB hardness and microstructure analysis

Research on Abrasive Wear Behavior of Laser Cladding Layers of High - Speed Steel Powder Type HS6-5-2 - M2

The paper presents the wear behaviour on a rotating disk which carried abrasive paper of laser cladding layers with high-speed steel powder type HS6-5-2 - M2 compared to steel samples of the same quality but heat treated in volume. To see how temperature affects the wear behaviour by abrasion of the laser cladding alloy and the classically hardened steel, samples have been heated to 450 °C, 550 °C, 650 °C and 700 °C during a four hour exposure, after which they were subjected to testing. It was monitored the hardness and wear mass variation with temperature and the variation of micro-hardness in the laser cladding layer. In order to point out the microstructural aspects of the samples metallographic analyses were performed