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EN
This work is a Copper oxide (CuO) thin films were effectively produced using cold spray technique. The process take place in an inert gas (helium) without using catalyst. Nano CuO was deposited on a glass slide, using helium as carrier gas heated to 100, 200, 300, and 400oC, respectively on heated glass substrates at 300°C. The effect of structural and electrical properties was examined at each temperature for each film. AFM images show that the CuO thin film have different diameters ranging from 80 to 600 nm, and low surface roughness about 20.9 nm. The measured value of copper oxide resistivity was found to be decrease very much with the increasing temperature. All the result showed that copper oxide is suitable material for photovoltaic applications. This research is part of a larger work for the solar cells industry. Therefore, the aim of this research is to study the electrical properties of solar cells in the primary stages of manufacturing from available materials at low costs.
EN
Purpose: Measurement of the adhesion of a Ti coating applied by cold spraying on metal substrates with different elastic modulus. An attempt to analytically describe the experimental results, considering cold gas spray parameters such as working gas, pressure p and temperature T. Design/methodology/approach: Ti coating was sprayed on flat bars made of metal: copper, magnesium, brass, titanium, Al 7075, Al 2024 and steel with dimensions of 4x50x400 mm. All coatings were applied under the same spray conditions (p = 3.8 MPa, T = 800ºC, spray distance l = 50 mm, and spray spead V = 400 mm/s). The state of plastic deformation of coatings and substrates was examined using optical methods, and the adhesion strength was measured with the POSITEST tester. Findings: The experimental results are presented graphically. The adhesion force as a function of the relative modulus of elasticity showed a maximum. At this time, the mutual penetration depth of the coating and the substrate showed a minimum. The extremes of the relationships mentioned above occurred for points where the relative modulus of elasticity took the value one. The curve described by formula (1) was fitted to the distribution of adhesion points as a function of the relative elastic modulus. The function parameter described by formula (1) is related to the spray parameters (p, T). Research limitations/implications: To achieve a better accuracy of the analytical description of the adhesion of coatings deposited with cold gas, tests should be carried out on a larger number of substrates. The validity of the presented interpretation should be checked by applying coatings from other materials. Practical implications: In coating technologies, adhesion is a key concept. A coating with high adhesion strength is used primarily in regeneration and anti-corrosion protection processes. The analytical relationship between adhesion, relative modulus of elasticity and cold gas spray parameters will significantly speed up the selection of optimal spray parameters. Cold spray technology is a cost-intensive technology, so the economic element is not without significance. Originality/value: The article presents a method for limiting the number of variables on which the quality of the applied coatings depends. The relationship between the adhesion force, the relative elastic modulus and the selected spray parameters are indicated.
EN
Thermal/cold spray deposition were used for additive manufacture of oxide dispersion strengthened (ODS) steel layers. Mechanically alloyed F/M ODS steel powders (Fe(bal.)-10Cr-1Mo-0.25Ti-0.35Y2O3 in wt.%) were sprayed by a high velocity oxygen fuel (HVOF) and cold spray methods. HVOF, as a thermal method, was used for manufacturing a 1 mm-thick ODS steel layer with a ~95% density. The source to objective distance (SOD) and feeding rate were controlled to achieve sound manufacturing. Y2 Ti2 O7 nano-particles were preserved in the HVOF sprayed layer; however, unexpected Cr2 O3 phases were frequently observed at the boundary area of the powders. A cold spray was used for manufacturing the Cr2 O3 -free layer and showed great feasibility. The density and yield of the cold spray were roughly 80% and 45%, respectively. The softening of ODS powders before the cold spray was conducted using a tube furnace of up to 1200°C. Microstructural characteristics of the cold sprayed layer were investigated by electron back-scattered diffraction (EBSD), the uniformity of deformation amount inside powders was observed.
4
Content available remote Properties of titanium coating deposited using spheroidal powders by cold spraying
EN
Purpose: The purpose of this study was to investigate the microstructure and the properties of the Ti coatings cold sprayed using spheroidal powder on the Al 7075 alloy. Design/methodology/approach: The Ni powder with irregular shape of grains was applied in the cold spraying process. The coatings were sprayed by means of a Impact Innovations 5/8 system with of nitrogen as process gas. Findings: The high kinetic energy of titanium particles causes their significant deformation and splats strongly adhere to the substrate and to each other. Cold sprayed titanium coatings exhibit negligible porosity and different mechanical properties caused by varying deformation degree of titanium powder. There were no phase changes in titanium powder during the spray process, and the coating consist of crystalline titanium. Practical implications: Titanium and its alloys have unique properties such as a high strength to weight ratio, excellent corrosion resistance and bio-compatibility. These features make it a material that is ideally suited for use in the aerospace, medical, and corrosive industries. Originality/value: The main advantage of cold spraying is elimination of influence of temperature on the particles of the coating material and the substrate that occurs in conventional thermal spraying methods. Therefore, the properties of such formed coatings are not available in other technologies.
5
Content available remote Characterization of thermally oxidized titanium based coating
EN
Purpose: Aim of the study is to improve the bioactivity of CoCr alloy upon covering the surface with titanium based coating. Design/methodology/approach: CoCr alloy was coated by cold spraying of powder mixture having a composition of 92 wt.%Ti + 8 wt.%Al. Coated samples were thermally oxidized at 600°C for 60 hours. Characterization of the coating was made by X-Ray diffraction analyses, microstructural surveys, cross-section and surface SEM elemental mapping analyses, roughness and hardness measurements. Findings: Results showed that sequential application of cold spray and thermal oxidation processes provided the multi-layered coating consisting of an inner titanium based layer and an outer oxide layer consisted of TiO2 and Al2O3. Thermal oxidation also caused the remarkable increasing in the surface hardness as compared to the as-cold sprayed state. Practical implications: Modifying the surface of CoCr metallic implants for long term success. Originality/value: Producing a multilayer coating on the surface of the CoCr alloy for biomedical application by sequential application of cold spray and thermal oxidation processes is the orginality of the study.
6
EN
The article presents the application of interlayers deposited by Low Pressure Cold Spraying (LPCS) in the soldering process. The problems concerning soft soldering of aluminium and copper were indicated and a solution with the use of metallic and composite interlayers was proposed. Wettability and spreadability tests with selected solders were performed to evaluate a solderability of various aluminium and copper LPCS coatings. Light and scanning microscopes were used to analyze solder dissimilar Al–Cu joints with previously deposited LPCS interlayer. What is more mechanical properties of the joints, e.g. microhardness and shear strength, were examined. Strength of the soldered Al–Cu joints with the LCPS interlayer highly depend on shape of powder used in spraying process. The joints with the interlayer sprayed with dendritic copper powder have low strength of about 20 MPa. However, the strength of soldered joints with the LPCS interlayer of spherical copper powder is significantly higher and amounts to 36.7 MPa.
EN
Composite coatings were deposited on commercially pure copper substrates by cold spraying of feedstock consisted of copper and Al2Cu powders. The amount of the Al2Cu powder incorporated in the feedstock varied in between 0 and 15 vol.%. Characterisations of the coatings were done by microstructural examinations, hardness and electrical conductivity measurements and wear tests. Composite coatings deposited from the feedstock containing 5 and 10 vol.% Al2Cu powder exhibited better electrical conductivity and superior wear resistance than the monolithic (Al2Cu free) copper coating. Presence of 15 vol.% Al2Cu in the feedstock diminished both the wear resistance and the electrical conductivity of the coating.
EN
The paper deals with effect of working gas pressure and temperature on surface stereometry of coatings deposited by low-pressure cold spray method. Examinations were focused on aluminium coatings which are commonly used to protect substrate against corrosion. A commercial Al spherical feedstock powder with admixture of Al2O3 (Al + 60vol.-%Al2O3), granulation -50+10 µm, was used to coat steel, grade S235JR. Thedeposited coatings were studied to determine their stereometry, i.e. roughness, transverse and longitudinal waviness, topography of surface and thickness as the functions of gas pressure and temperature. A profilometer and focal microscope were used to evaluate the stereometric properties. In order to reduce the number of variables, the remaining process parameters, i.e. shape and size of de Laval nozzle, nozzle-to-substrate distance, powder mass flow rate, linear velocity of spraying gun, were kept unchanged. The investigation confirmed influence of temperature and pressure on coating thickness as well as on the surface seterometry.
PL
W pracy badano wpływ ciśnienia oraz temperatury gazu roboczego na stereometrię powierzchni warstw uzyskanych metodą niskociśnieniowego natryskiwania na zimno. W badaniach skupiono się na wykonaniu powłok aluminiowych, które są powszechnie stosowane w celu ochrony podłoża przed korozją. Wykorzystano komercyjny proszek sferyczny Al z domieszką Al2O3 (w proporcji obj. 40% Al / 60% Al2O3) o granulacji -50+10 µm, którym pokryto stal S235JR. Przeprowadzone analizy miały na celu określenie stereometrii otrzymanych warstw, tj. chropowatości, falistości poprzecznej oraz wzdłużnej, topografii powierzchni oraz grubości, w zależności od ciśnienia i temperatury gazu. Do analizy właściwości stereometrycznych wykorzystano profilografometr oraz mikroskop konfokalny. W celu ograniczenia ilości zmiennych, pozostałe parametry procesu, tj. kształt i rozmiar dyszy de Lavala, odległość dyszy od podłoża, masowe natężenie przepływu proszku, prędkość liniowa palnika, pozostawiono na stałym poziomie. Przeprowadzone badania potwierdziły wpływ temperatury oraz ciśnienia gazu na grubość naniesionych powłok, jak również na stereometrię ich powierzchni.
9
Content available remote Taguchi optimization of the thickness of a coating deposited by LPCS
EN
The low-pressure cold spray (LPCS) technique is used to produce conducting, anticorrosive, insulating, etc., coatings. In order to increase the efficiency of the process the latter is often automated by attaching the spraying gun to a robot or a manipulator. However, because of the large number of interdependent parameters the thickness of the run obtained in one pass of the spraying gun may range from a few hundred micrometres to as much as a few millimetres. As a result, a coating with varied surface waviness and roughness is obtained. This paper focuses on determining the optimal LPCS process parameters yielding a coating having the desired thickness. For this purpose, the Taguchi method was employed whereby the experiment could be properly designed and the principal parameters having the greatest influence on the process could be determined. The L16′ orthogonal table, four key process parameters and four levels of values for each were used. The input parameters were: powder feeding rate, spraying gun travel velocity, gas pressure and temperature. The output parameter was coating thickness. For verification purposes composite (aluminium + alumina) coatings were deposited.
PL
W procesie nanoszenia powłok metodą Cold Spray cząsteczki są przyspieszane do dużych prędkości za pomocą rozgrzanego i sprężonego gazu, a po uderzeniu w podłoże osadzają się wskutek deformacji plastycznej. Ze względu na niską temperaturę występującą w tej metodzie wydaje się ona odpowiednia do metalizacji tworzyw sztucznych. W artykule zawarto analizę literaturową z zakresu metalizacji tworzyw sztucznych. Przedstawiono wyniki symulacji numerycznej MES nanoszenia proszku cyny na podłoże z tworzywa ABS. Analizie zostały poddane pola temperatury podczas procesu nanoszenia. Otrzymane wyniki zweryfikowano w oparciu o zdjęcia z mikroskopu skaningowego.
EN
In Cold Spray process particles are accelerated to high speed by heated and compressed gas, and after impact deposited on the substrate as a result of plastic deformation. Due to the low temperatures during the process the Cold Spray method seems to be appropriate to the metallization of plastics. The article includes analysis of the literature of plastics metallization. The results of numerical simulation of tin powder spraying onto ABS substrate plastic are presented. The temperature fields during the spraying process are analyzed. The obtained results are verified on the basis of scanning microscope images.
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