Wyniki 1-10 spośród 23 dla zapytania: authorDesc:"Barbara Kucharska "

Measurement of Fe-Cr-Ni coatings density in XRD analysis

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The article presents the measurement of the density of heat-resisting steel coatings using X-ray methods, XRD and GXRD. Coatings of a thickness of 8.5￿m deposited by the magnetron method were tested using targets made of AISI310S steel on a substrate of the same steel. The coatings were deposited at a negative table polarization voltage of -50V and an Ar flow pressure of 0.03 Pa. By us[...]

Effect of Al and Iradditions on surface morphology and topography of FeCrNi coatings

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The magnetron sputtering deposition (MSD) method belongs to the basic and the most important methods of depositing coatings in vacuum conditions, PVD [1÷3]. A very valuable advantage of this method is the possibility of depositing coatings, particularly those of complex chemical composition, in a broad range of thicknesses, starting from several angstroms. This method is successfully used for depositing coatings based on steels, also heat-resistant grades, which include 310S steel. In the chemical composition of this steel are the additions of Ni (~20%) and Cr (~25%) [4÷6]. For better resistance the chemical composition are enriched by addition of high melting elements [7, 8]. The properties of magnetron coatings depend on the sputtering process parameters, which influence the microstructure and the grain size of coatings [9, 10]. The essential purpose of applying coatings is to protect the substrate or to modify the properties of surface. This function can only be fulfilled by coatings that are tight and exhibit good adhesion to the substrate [11]. These conditions are applicable in particular to coatings intended for protection against corrosion in liquid solutions, as well as in high-temperature oxidation conditions [12÷15]. Also, in corrosion protection, surface smoothness plays an important role. Low surface roughness and the absence of surface defects inhibit the build-up of aggressive ions and deposits that might initiate pit corrosion [16]. The paper presents the investigation of the surface topography of magnetron coatings based on heat-resisting steel of 310S enriched Al and Ru additions. The AFM (Atomic Force Microscope), SEM (Scanning Electron Microscope), and profilometric techniques were used in the investigation. material Coatings of the composition of 310S heat-resisting steel, deposited on a substrate of the same steel by the magnetron sputtering method, were examined. The magnetron targets were two discs, eac[...]

A Low-Cost Temperature Attachment for in-situ Measurements in the X–ray Diffractometer

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The paper presents the design of a temperature attachment for in-situ measurements to be used in the Seifert 3003TT X-ray diffractometer owned by the Institute of Materials Engineering at the Czestochowa University of Technology, but being also able to be adapted to other types of diffractometers. The schematic diagram of the device, its temperature characteristics and the method of mounting [...]

Własności rezystancyjne powłok PVD ze stopów AlSi DOI:10.15199/13.2015.8.12


  Aluminium znajduje się na czwartym miejscu wśród metali o najlepszym przewodnictwie elektrycznym, za srebrem, miedzią i złotem. Przewodnictwo elektryczne aluminium, wynoszące 1,72×10-8 Ω ⋅ m (w 20oC), stanowi tylko ok. 60% przewodnictwa miedzi, mimo to jest ono również szeroko stosowne w urządzeniach elektrotechnicznych. Powodem tego jest mała masa właściwa (gęstość) aluminium 2,7 g/cm3, stanowiąca ok. 30% gęstości miedzi, a także lepsza odporność korozyjna. Również za sprawą tych korzystnych własności aluminium i jego stopy są szeroko stosowane w przemyśle motoryzacyjnym, lotnictwie i budownictwie [1, 2]. Wśród stopów aluminium do najbardziej popularnych należą siluminy - stopy odlewnicze, w których głównym dodatkiem stopowym jest Si. Dodatek Si poprawia lejność stopu, zwiększa twardość i odporność na ścieranie [3]. Si charakteryzuje się bardzo małym współczynnikiem rozszerzalności cieplnej (aSi~3×- 10-6/K) w porównaniu do aluminium (αAl~22,2×10-6/K) zatem sprzyja stabilizacji wymiarowej detali wykonanych ze stopów Al- Si, takich jak np. tłoki silników ze stopu AlSi20 [4,5] ale również obudowy urządzeń elektronicznych [6]. Ze stopów o mniejszym stężeniu Si wykonuje się m.in. odporne na ścieranie powłoki na blachach do produkcji tłumików samochodowych [7]. Odporność na ścieranie tym stopom zapewniają twarde kryształy Si rozmieszczone w osnowie aluminium. Z punktu widzenia własności plastycznych istotnym jest aby kryształy Si miały jak najmniejsze wymiary, co osiąga się na drodze szybkiego chłodzenia (odlewanie ciśnieniowe) i modyfikacji, czyli wprowadzenia sztucznych zarodków krystalizacji (modyfikatorów) [3]. W niniejszej pracy do wykonania stopów Al-Si zastosowano metodę PVD magnetronowego rozpy[...]

New possibility to extend Wagner method for oxidation process modelling

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Diffusion processes during the selective oxidation of an alloy containing a noble metal and a oxidizable metal were theoretically analyzed by C. Wagner. He had shown the analytical method to calculate the oxidation rate (growth of the scale) as a function of initial concentration of the reacting metal. Wagner simplified the problem of alloy oxidation assuming the constant concentration at the[...]

Influence of heat treatment on the phase composition of Al-Si coat on X2CrTi12 high chromium steel

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In the article there was presented an influence of heat treatment saturating and ageing on the Al-Si layer placed on X2CrTi12 steel used in exhaust systems production. The material was subjected by microscopic and -X-ray phase analysis. The morphology of the crystals of silicon was changed from big and acicular shape forms to small and rounded shapes after heat treatment process. An eliminati[...]

The effect of cyclic deformation on the level of residual stress in the magnesium alloy Az91

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The paper presents the results of studies on the effect of heat treatment and cyclic deformation on the properties of the magnesium alloy AZ91. The alloy was subjected to heat treatment by solutioning and ageing (420 °C/24 h/powietrze+210 °C/4 h/powietrze) and then to cyclic uniaxial zero-start pulsating loads. The maximal amplitudes of cyclic loads 54 and 74 MPa were lower than the offset yield strength of the alloy. The microstructure of the alloy is presented, while the properties of the alloy before and after cycling loading (up to 50 and 70 cycles) are determined by measurements of residual stress made by the X-ray method of sin2ψ. It has been found that cyclic deformation causes the strengthening of the alloy AZ91. The strengthening of the alloy is found to increase with i[...]

The effect of structure on the stability of Al-Si coatings under salt mist conditions

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The high corrosion resistance of Al alloys, as well as their sufficient heat resistance, have contributed to the use of these alloys for anodic protective coatings being applied on steels intended for, e.g., exhaust system elements. Developing coatings that would meet the ever-increasing operation parameters of cars is the subject of continuous research work. The new customer demands, technological solutions, and increasing car performance parameters are all urging the designers to use increasingly expensive steel grades with bettered mechanical parameters. However, a significant limitation on the wide application of stainless steels is the fact that, in spite of the absence of visible corrosion products, in acidified oxidizing media containing some anions, these steels undergo spontaneous, often localized dissolution. Due to the weight and economy of product, the basic element used for protective coatings in the automotive industry still remains to be aluminium [1÷4]. The problem of properly selected protective coatings is crucial in the manufacture of car exhaust silencers, because the whole exhaust system, in addition to mechanical damage during service, is exposed to aggressive chemical agents that accelerate the steel corrosion processes. At present, steels of a chromium content above 10% with an aluminium-silicon hot-dip coating applied are used for the manufacture of car exhaust systems. Exhaust system elements are formed in a stamping process. The main technological problem during their production from aluminium-coated steel sheet is to maintain the integrity of the coating. This problem has been partially solved by using silicon as an alloying element. However, it has been demonstrated in the author’s studies, that such coatings often exhibit an uneven arrangement and size of silicon crystals (as a result of the trade-off between the technical capabilities to produce a coating by the hot-dip coating method and th[...]

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