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A novel approach to improve reliability of aerosol jet printing process

Winnicki Marcin, Łapa Wojciech, Świadkowski Bartosz

Eksploatacja i Niezawodność

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2024

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Vol. 26, no. 2

art. no. 180012

EN

Additive manufacturingis gaining interest for printing of noble metals. In this study, aerosol jet printingwas applied to fabricate traces from commercialsilver nanoparticleink. A self-built three dimensional printing machine was used without or with in-line substrate heating. A conductive traces were printed on flexible polyimide substrates. Subsequently, sintering was conducted by furnace or near-infrared source. Examination of the sample using scanning electron and atomic force microscopy revealed the existence of both micro-and nanoscale pores in the structure. Local open porosity, aerosol extensive spatter and wide porous overspray were key defects found in samples printed without substrate heating. All the features affect the properties and reliability of silver prints.In-line process heating increased the concentration of nanoparticles and limited defects formation. What is more, the width of traces decreased from 31 µm to 19 µm with simultaneous thickness increase from 1.2 to 5.5 µm due to substrate heating. The final structure was influenced by sintering method and its time. Elongated time of sintering decreased porosity and roughness of the printed traces. Nevertheless,IR sintering provided the smoothest sample surface with lowest Sa roughness of 16 nm,and significantly improved bonding of aggregates. What is more, the printed structure had a measured sheet resistance of 8.3×10−2Ω/□.

2

Tribological wear analysis of Ti-Al composite coatings applied with the cold spray method

Rutkowska-Gorczyca Małgorzata, Wiśniewski Marcin, Dziubek Mateusz, Kowalewski Piotr, Winnicki Marcin

Tribologia

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2023

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nr 3

63--70

EN

The possibility of using the low-pressure cold gas spraying (LPCS) method to create composite coatings has been known and used for a long time. This method makes it possible to create coatings from physically and chemically different powders and to regenerate components damaged during operation. Composite coatings of titanium and aluminium at different weight concentrations were selected for the study. The research was conducted to optimise the influence of the chemical composition of the composite coatings on their tribological properties. This paper presents the results of tribological wear testing of composite coatings applied using the low-pressure cold gas spray (LPCS) method. Wear resistance tests were performed using the ball-on-plate method in reciprocating motion using a steel ball. Tribological testing of the coatings included determining the effect of contact force on wear and the value of the kinetic coefficient of friction of the friction pairs tested. The study determined the optimum chemical composition of the Ti-Al composite coatings to improve wear properties.

PL

Możliwość zastosowania metody niskociśnieniowego natrysku zimnym gazem (LPCS) do tworzenia powłok kompozytowych jest znana i wykorzystywana od bardzo dawna. Metoda ta pozwala na tworzenie powłok z różnych pod względem fizycznym i chemicznym proszków oraz na regenerację elementów uszkodzonych podczas eksploatacji. Do badań wybrano kompozytowe powłoki tytanu i aluminium przy różnych stężeniach wagowych. Badania przeprowadzono w celu optymalizacji wpływu składu chemicznego powłok kompozytowych na ich właściwości tribologiczne. W pracy zaprezentowano wyniki badań zużycia tribologicznego powłok kompozytowych nanoszonych z zastosowaniem metody niskociśnieniowego natrysku zimnym gazem (LPCS). Badania odporności na zużycie wykonano przy użyciu metody ball-on-plate, w ruchu posuwisto-zwrotnym z wykorzystaniem stalowej kulki. Badania tribologiczne powłok obejmowały określenie wpływu siły nacisku na zużycie oraz wartość współczynnika tarcia kinetycznego badanych par trących. Badania pozwoliły określić optymalny skład chemiczny kompozytowych powłok Ti-Al w celu poprawy właściwości eksploatacyjnych.

3

Investigation of aerosol droplets diameter generated in aerosol jet printing

Łapa Wojciech, Winnicki Marcin, Orłowska Karolina

Materials Science Poland

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2022

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Vol. 40, No. 4

78--90

EN

Aerosol jet printing is a contactless direct-write technique that could be used for the deposition of a variety of materials. First, used for electric paths, the technology was explored for many applications. The substantial part of the process is the generation of aerosols. The size of the droplets and the stability of the process affect the quality of the sprayed lines. This article investigates the diameter of the sprayed droplets, allowing future comparison of the results with sprayed lines. Droplets from ultrasonic and pneumatic generators were sprayed at their outlet on the polyethylene terephthalate (PET) foil. Using a digital microscope and the built-in algorithm, the diameter of the droplets was measured, and the dataset was collected as CSV files and served as a background to the box plot. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) scans were applied to verify the results obtained. The ink parameters used in the process have an influence on the aerosol generation and droplet diameter, whereas the carrier gas pressure has an impact mostly on the droplet diameter. In this case, the aerosol was produced from three types of ink in combination with two generators. For inks with a dynamic viscosity below 6.5 m·Pa-1·s-1a stable range of 5–10 μm droplet diameter was observed. A high-viscosity ink (7.5–10.5 m·Pa-1·s-1) produced droplets with diameter in the range of 6–25 μm. The diameter of the droplet decreased from 7–22 μm to 1–5 μm with a reduction in the dynamic viscosity from 7.5–10.5 m·Pa-1·s-1 to 4.5–5.5 m·Pa-1·s-1.

4

A new approach to flux deposition for brazing aluminium by low pressure cold spraying

Wojdat Tomasz, Winnicki Marcin, Pabian Jarosław

Materials Science Poland

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2022

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Vol. 40, No. 4

114--124

EN

This paper presents the results of study on the possibility of Nocolok flux deposition to aluminium substrates using the low-pressure cold gas spraying (LPCS) method. An innovative method of applying flux in the form of a powder without organic adhesive additives was proposed, allowing strict control of the deposited material. The influence of the flux powder feeding rate (PFR – 4.5 g/min, 6.3 g/min and 8.5 g/min) on the efficiency of the brazing process of AA3003 aluminium alloy plates was investigated. The results of energy dispersive spectrometry (EDS) analysis of the deposited flux coatings are presented for various process parameters. The wettability tested by spreading the B-AlSi12 filler metal on flux-covered aluminium substrates increased significantly with increasing PFR – the contact angle decreased from 21.0° to 4.6°. Microstructure analysis confirmed the high quality of the brazed joints, which were devoid of braze incompatibilities.

5

Corrosion Damage Mechanisms of TiO2 Cold-Sprayed Coatings

Lachowicz Marzena, Winnicki Marcin

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

975--985

EN

Cold spraying as a low-temperature coating deposition method is intended for thermally sensitive materials. Due to its precise temperature control, it limits the formation of structural defects, and can therefore be easily applied to spray corrosion protective coatings made from metal or metal-ceramic powders. However, the formation of pure ceramic coatings with the use of cold spraying is still not so common. Titanium dioxide is one of the most interesting ceramics due to its photocatalytic properties. Nevertheless, these types of coating materials usually work in a corrosion favoring humid atmosphere. In the presented paper, amorphous TiO2 powder was deposited onto aluminum alloys and steel substrates and then submitted to potentiodynamic corrosion tests in a 3.5 wt.% NaCl solution. The as-sprayed coating showed phase transition from amorphous TiO2 to anatase, and also revealed porosity. As a result, electrolytes penetrated the coating and caused undercoating corrosion in the tested environment of an aqueous NaCl solution. The analysis of the potentiodynamic curves showed that the presence of the coating decreased corrosion potential on both substrates. It arose from the mixed phases of TiO2, which consisted of photocathode - amorphous material and photoanode - crystalline anatase. The phase mixture induced the galvanic corrosion of metallic substrates in the presence of electrolytes. Moreover, pitting-like corrosion and coating delamination were detected in aluminium alloy and steel samples, respectively. Finally, the corrosion mechanism of the titanium dioxide coatings was characterized and described.

6

Analysis of the Tribological Properties of Cu-aTiO2 Composite Coatings Applied by the Cold Spray Method

Rutkowska-Gorczyca Małgorzata, Ptak Anita, Winnicki Marcin

Tribologia

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2020

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nr 4

51--57

EN

The properties of copper have been known and used for a very long time, and research has also been carried out for a long time to expand the applications of this material. One of the methods increasing the bactericidal and bacteriostatic effect of copper is modification by means of the TiO2 phase. The research was conducted in order to determine the impact of modification of copper coatings with TiO2 titanium dioxide on their tribological properties. The paper presents the results of studies on tribological wear of composite coatings applied on steel using the method of low-pressure cold gas spraying (LPCS). The tests of resistance to abrasive wear were carried out in a ball-disc combination in reciprocating motion. The analysis of the resistance to abrasive wear of the tested coatings included the determination of the impact of the pressure force on the intensity of wear and the kinetic friction coefficient of the tested friction pairs. It was found that the samples covered only with copper coatings were characterized by a higher value of friction coefficient in relation to the substrate made of AISI 316l steel. The modification of copper with the submicron particles TiO2 fraction does not increase the value of friction coefficient. The value of this parameter is maintained at a similar level regardless of the applied counterspecimen.

PL

Właściwości miedzi są znane i wykorzystywane od bardzo dawna, od dawna również są prowadzone badania nad zwiększeniem możliwości zastosowania tego materiału. Jedną z metod zwiększających działanie bakteriobójcze i bakteriostatyczne miedzi jest modyfikacja fazą TiO2 . Badania przeprowadzono w celu określenia wpływu modyfikacji powłok miedzianych ditlenkiem tytanu TiO2 na ich właściwości tribologiczne. W pracy zaprezentowano wyniki badań zużycia tribologicznego powłok kompozytowych nanoszonych na stal metodą niskociśnieniowego natrysku zimnym gazem (LPCS). Badania odporności na zużycie ścierne wykonano w skojarzeniu kula–tarcza, w ruchu posuwisto-zwrotnym. Analiza odporności na zużycie ścierne badanych powłok obejmowała określenie wpływu siły nacisku na intensywność zużywania i współczynnik tarcia kinetycznego badanych par trących. Stwierdzono, że próbki pokryte wyłącznie powłoką miedzianą charakteryzują się wyższą wartością współczynnika tarcia, w stosunku do podłoża ze stali AISI 316l. Modyfikacja miedzi frakcją submikronowych cząstek TiO2 nie powoduje zwiększenia wartości współczynnika tarcia. Wartość tego parametru zostaje zachowana na podobnym poziomie niezależnie od zastosowanego obciążenia przeciwpróbki.

7

An innovative method of applying fluxes using the low-pressure cold gas spraying method

Wojdat Tomasz, Winnicki Marcin, Mirski Zbigniew, Żuk Agata

Welding Technology Review

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2019

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R. 91, nr 10

17--24

EN

In the paper, the results of tests of flux application for aluminum brazing processes using the low-presure cold gas spraying method, are presented. It was pointed out that this method could be used as an alternative to current methods of flux application, among others in the production of aluminum heat exchangers. The results of wettability tests made with braze spreading method on fluxed substrates and metallographic investigations of brazed joints are presented. Good quality of brazed joints without incompatibilities and good mechanical properties have been demonstrated.

PL

W artykule przedstawiono wyniki badań nanoszenia topnika do procesów lutowania aluminium metodą niskociśnieniowego natryskiwania zimnym gazem. Wskazano na możliwość zastosowania niniejszej metody, jako alternatywnej dla obecnie stosowanych metod aplikacji topników m.in. w produkcji aluminiowych wymienników ciepła. Przedstawiono wyniki badań zwilżalności wykonane metodą rozpływności lutów na topnikowanych podłożach oraz badania metalograficzne złączy lutowanych. Wykazano dobrą jakość połączeń lutowanych, bez niezgodności lutowniczych oraz dobre właściwości mechaniczne.