Papers by Author: M. Ossowski

Abstract: Structure of the nitride-oxide surface layers, formed using glow discharge technique at low temperature (between 200 and 380°C) changing the parameters of the process, was examined applying X-ray diffraction as well as transmission electron microscopy. The phase analysis was supported by results obtained from XPS measurement. Obtained results have shown that low temperature nitriding/oxiding produced the thin layers (18 ÷ 30 nm in thickness), which consist of titanium nitride and oxide phase. Low amount of the nickel-titanium oxide was also identified in the layer produced at higher temperature. Decrease of nitriding/oxidizing temperature below 300oC cause that between nitride-oxide surface layer and NiTi alloy did not create the intermediate layer of Ni3Ti phase. The results were verified and confirmed by observation carried out using high resolution electron microscopy. The corrosion properties of such coatings were tested in the physiological Tyrod’s solution using the cyclic potentiodynamic polarization method.

Abstract: The paper presents the results concerning the microstructure of Ti – Al intermetallic layers produced on a TA6V titanium alloy by the “duplex method”. This method combines vacuum evaporation coating of aluminum with glow discharge assisted heat treatment of the deposited films. It has been found that this combination of surface engineering techniques yields multi – layered films of the diffusive character. The films contain intermetallic phases from Ti – Al system which ensure a high microhardnes and good wear resistance. It is finally suggested that these properties can significantly widen application range of titanium alloy parts in aerospace.

Abstract: The rapid progress in engineering enhances the demands set on materials requiring better mechanical properties, resistance to frictional wear, resistance to corrosion and erosion etc. These demands can be satisfied by e.g. applying various surface engineering techniques which permit modifying the microstructure, phase and chemical composition of the surface layers of the treated parts. By subjecting a laminate composite: α+β titanium alloy - TixAly intermetallic phases produced by diffusion bonding of titanium alloy and aluminum with the hybrid surface treatment that consists of magnetron sputtering and glow discharge assisted oxidizing or by the glow discharge nitriding process we can produce a composite built of several zones arranged in the following sequence: Al2O3/ TixAly intermetallic phases/titanium alloy/TiAl3/ titanium alloy/ TixAly intermetallic phases/ Al2O3 or TiN+αTi(N)/ titanium alloy/ TiAl3/ titanium alloy/αTi(N) +TiN. The paper presents the structure, phase composition and properties such as the resistance to frictional wear and to corrosion of a new constructional material - a laminate composite Ti –Al with diffusion surface layers, which widen significantly the application range of titanium alloys.

Abstract: The rapid progress in engineering enhances the demands set on materials requiring better mechanical properties, resistance to frictional wear, corrosion and erosion etc. These demands can be also satisfied by e.g. applying various surface engineering techniques which permit modifying the microstructure, phase and chemical composition of the surface layers produced on the treated parts. A prospective line of the development is the production of the intermetallic layers by combining various methods aimed to improve essentially the performance properties and service life of the treated parts. The paper presents properties of the Al2O3+TiAl3+TiAl+Ti3Al type layer produced on titanium alloy Ti6Al2Cr2Mo by duplex method combined with magnetron sputtering process of aluminium coating with a glow discharge assisted treatment. The results of the examinations: microstructure, chemical and phase composition, frictional wear resistance and mechanical properties are discussed. Produced composite surface layers have the diffusion character and a precisely specified structure, chemical and phase composition and good wear and corrosion resistance what can widen significantly application range of treated parts.