Papers by Author: Robert Skoblik

Abstract: . Literature provides three basic methods of explosive cladding, developed by Darenport and Person. Welding trials were performed in two- and three-layer arrangements, where in the second case, copper plates were welded with plates made from aluminium alloys with an interlayer of pure aluminium. Explosive welding technology does not always allow for joining of sheets of specific thicknesses. In order to obtain such thickness, they need to be rolled. The paper presents results of numerical study of asymmetrical rolling process of multilayer plates M1E-Al99.8-AlMg5. Numerical modeling of rolling of multilayer plates was realized by means of Forge 2D program that is based on finite element method. Obtained research results enabled to elucidate the process of rolling of multilayer plates.

Abstract: Modern materials on intermetallic matrix are in the scope of research of many scientific – research centers in Poland [1]. Intermetallic systematic alloys containing aluminium have high resistance to oxidation, abrasive corrosion and fatigue as well as heat resistance. That is why they are applied in the production of machine parts used in hard service conditions (internal combustion turbine blades, exhaust valves, turbo-blower rotors) [2]. Intermetallic coatings can be obtained by means of plasma spraying. Thermal spraying technology is widely used due to the possibility of increasing the service properties in surface layers (strength property, tribological, anti-corrosive and decorative property) as well as coating application on machine parts elements, on tools for plastic working (forging moulds busters, piston rods, gear wheels teeth, crank journals, valve seats, and combustion engine cylinders) [3, 4]. NiAl and Ni3Al coatings are characterized by high fatigue resistance, heat resistance and considerable corrosion resistance [5]. Coatings obtained by thermal spraying have high surface roughness. Thus, subsequent plastic treatment is advisable for plasma-sprayed intermetallic coatings. Therefore it is vital to define to what extent the change of unit pressure will influence reduction of surface roughness of intermetallic coatings. For this purpose experimental upsetting research was carried out on C45 steel samples having NiAl and Ni3Al coatings for the following unit pressures p = 500 MPa, p = 800 MPa, p = 1100 MPa.

Abstract: The paper presents the effect of dispersion phase of Al2O3 on selected potential properties of composite coatings on the nickel base. Coatings of Ni-Al-Al2O3 were applied on the steel specimens using the subsonic process of flame spraying. The specimens were then subjected to both cold and hot plastic working by rolling and also cold pressing by the hydraulic press. Plastic working is an alternative to machining, as the method of finishing of coats applied by flame spraying. The paper presents the findings of the research into the possibility of using plastic working (hot and cold rolling and pressing) to obtain the selected properties of the flame sprayed Ni-Al alloy coatings and Ni-Al-Al2O3 composite coatings. The alloy coatings had a single-phase structure, namely boundary solution α , of the maximum 10% aluminium solubility in the crystal lattice of nickel, whereas in the composite coatings the volume content of non-metallic material Al2O3 was: 0, 15, and 30 %.