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Effects of ageing heat treatment temperature on the properties of DMLS additive manufactured 17-4PH steel

Świetlicki Aleksander, Wlaczak Mariusz, Szala Mirosław, Turek Marcin, Chocyk Dariusz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 4

art. no. e146237

EN

Additive manufacturing (AM) is a modern, innovative manufacturing method that enables the production of fully dense products with high mechanical properties and complex shapes that are often impossible to obtain by traditional methods. The 17-4PH grade steel is often applied where high mechanical performance is required. 17-4PH, or AISI 630, is intended for precipitation hardening, an operation that combines solution and ageing treatments and is used to significantly change the microstructure of the steel and enhance its mechanical properties. This study investigates the effect of precipitation hardening on the properties of 17-4PH steel. To examine microstructure and morphology, metallographic tests were performed together with phase composition and chemical composition analyses. Mechanical parameters were determined via Vickers hardness testing and the Oliver-Pharr method. Samples were fabricated using direct metal laser sintering (DMLS), which is one of the powder bed fusion methods. The use of a constant solution treatment temperature of 1040_C and different ageing temperatures made it possible to evaluate the effects of ageing temperature on the mechanical properties and microstructure of 17-4PH. The presence of face-centered cubic FCC g-austenite and body-centerd cubic BCC a-martensite structures were detected. The tests revealed that – similarly to the wrought material – the highest hardness of 382_10:3 HV0:2 was obtained after ageing at 450_C. The nanoindentation test showed the same H/E ratio for the sample after fabrication and after solution treatment at 0.016769, but this value increased after ageing to 127–157.5%. The sample aged at 450_C was characterized by the highest H/E ratio of 0.026367, which indicates the highest wear resistance of this material under employed treatment conditions. In general, the sample treated at 450_C showed the best performance out of all tested samples, proving to have the smallest grain size as well as high Vickers and nanoindentation hardness. On the other hand, the use of solution treatment led to reduced hardness and improved workability of the AM material.

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Thermal Desorption of Argon Implanted into Gallium Arsenide

Turek Marcin, Droździel Andrzej, Pyszniak Krzysztof, Węgierek Paweł

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 4

318--326

EN

Thermal desorption of Ar implanted with energies 150 keV and 100 keV with fluence 1×10^16 cm^-2 into GaAs is considered. A sudden release of Ar is observed in temperature range 1100 -1180 K as a single narrow peak in TDS (Thermal Desorption Spectroscopy) spectra. This is accompanied by a strong background signal from atmospheric Ar trapped in various parts of the spectrometer. Desorption peak shift analysis allows estimation of desorption activation energy values - these are 3.6 eV and 2.5 eV for implantation energies 150 keV and 100 keV, respectively. These results are comparable to that measured for Ar implanted into germanium target.

3

Suppressing of Co-Extracted Electrons in a Negative Ion Source-Numerical Simulation

Turek Marcin, Węgierek Paweł

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 5

1--10

EN

Electron co-extraction and suppression by a transverse magnetic fields is studied within a two dimensional particle-in-cell numerical model of surface ionisation ion source with beveled extraction opening. A novel approach of data presentation is proposed, based on the fact that dependences of co-extracted current on the filter strength could be approximated by four parameters only, describing e.g. initial electron current value and cut-off B value. In the paper the influence of extraction system geometry is considered – it is shown that the cut-off B value increases with the size of the opening in the extraction electrode, while the inclination of the extraction opening walls does not play any significant role. It is demostrated that the most of electron is eliminated by hiting the extraction electrode walls, however up to 30 % of electrons were lost by encountering the extraction channel walls due to the modification of their trajectories by the filter field. The influence of the magnetic filter field placement is also investigated – the center of the filter field has to be no further than 2 mm form the extraction channel orifice in order to achieve minimal values of the cut-off field (~20 mT). The possibly low extraction voltages are preferable, as the ammount of co-extracted electrons grows rapidly with Vext resulting in e.g. threefold increase of cut-off parameter value when extraction voltage is changed from 1 kV up to 10 kV. Within the considered model the filter field does not have any significant influecne on extracted H- current.

4

New Approach to Non-Volatile Metal Ion Production Using Plasma Ion Source with Internal Evaporator

Turek Marcin, Droździel Andrzej, Pyszniak Krzysztof, Filiks Janusz, Węgierek Paweł

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 5

20--27

EN

A new approach to application the internal evaporator in an arc discharge ion source is presented, namely a crucible with a plug made of feeding substance. This solution is suitable especially for high-melting point metallic feeding substances. The ion source was tested using Ni and Cr. Basic ion source characteristics, i.e. dependences of ion current and discharge voltage on discharge and filament currents as well as on the external magnetic field flux density are shown and discussed in order to find optimal working conditions. The maximal ion currents were 18 μA for Ni+ and 38μA for Cr+. The stability of the ion current was also tested. It was proven that ion source is able to provide intense ion beam current long enough to perform irradiations with the fluence of ~5×1015 cm-2 confirming the usefulness of the design for ion implantation purposes.

5

Modification of Optical, Electronic and Microstructural Properties of PET by 150 keV Cs+ Irradiation

Musiatowicz Michał, Turek Marcin, Droździel Andrzej, Pyszniak Krzysztof, Grudziński Wojciech

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 5

11–19

EN

Thick (0.125 mm) sheet samples of PET were irradiated with 150 keV Cs+ ion beam with fluences in the range from 10^13 cm^-2 up to 10^16 cm^-2). Raman and UV-VIS spectroscopy measurements shown destruction of numerous bonds within the polymer – this effect intensifies with fluence. Raman spectroscopy shows the presence of amorphous graphitelike structures as the broad G band appears in the collected spectrum. The analysis of absorbance spectra also confirms formation of numerous carbon clusters leading to a formation of vast conducting structures in the modified layer of the polymer. One can observe the decrease of optical bandgap from 3.85 eV (typical for pristine PET) to 1.05 eV for the sample implanted with the highest fluence, the effect is weaker than for lighter alkali metal ions. The estimated average number of C atom in a clusters reaches in such case values close to 1100. The changes in the polymer structure lead to intense reduction of electrical sheet resistivity of the modified samples by ~ 8 orders of magnitude in the case of severely modified sample. The dependence of resistivity on temperature has also been measured. The plots of ln(σ) vs 1/T show that band conductivity or nearest neighbor hopping between conducting structures prevail in the considered case

6

Crystal Lattice Damage and Recovery of Rare-Earth implanted Wide Bandgap Oxides

Sarwar Mahwish, Ratajczak Renata, Ivanov Vitalii, Mishra Sushma, Turek Marcin, Wierzbicka Aleksandra, Woźniak Wojciech, Guziewicz Elżbieta

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 5

147--154

EN

Rare earth (RE) elements are important for the optical tuning of wide bandgap oxides (WBO) such as β-Ga2O3 or ZnO, because β-Ga2O3:RE or ZnO:RE show narrow emission lines in the visible, ultra-violet and infra-red region. Ion implantation is an attractive method to introduce dopant into the crystal lattice with an extraordinary control of the dopant ion composition and location, but it creates the lattice damage, which may render the dopant optically inactive. In this research work, we investigate the post-implantation crystal lattice damage of two matrices of wide-bandgap oxides, β-Ga2O3 and ZnO, implanted with rare-earth (RE) to a fluence of 5 x 10^14, 1 x 10^15 and 3 x 10^15 atoms/cm^2, and post-growth annealed in Ar and O2 atmosphere, respectively. The effect of implantation and annealing on both crystal lattices was investigated by channeling Rutherford backscattering spectrometry (RBS/C) technique. The level of crystal lattice damage caused by implantation with the same RE fluences in the case of β-Ga2O3 seems to be higher than in the case of ZnO. Low temperature photoluminescence was used to investigate the optical activation of RE in both matrices after performed annealing.

7

Termodesorpcja argonu implantowanego do germanu

Turek Marcin, Droździel Andrzej, Pyszniak Krzysztof, Vaganov Yuriy A.

Przegląd Elektrotechniczny

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2020

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R. 96, nr 8

126--130

PL

Badano termodesorpcję Ar zaimplantowanego do germanu (z energią 100 keV i 150 keV, dawka 2×1016 cm-2). Zaobserwowano gwałtowne uwolnienia Ar w temperaturach 790-840 K w postaci wąskich wierzchołków w widmach TDS, co świadczy najprawdopodobniej o uwalnianiu Ar zgromadzonego w postaci bąbli we wnękach w Ge. Analiza przesunięć położenia wierzchołków pozwoliła oszacować wartości energii aktywacji desorpcji – wynosi ona 3.2 eV (100 keV) i 2.2 eV (150 keV) - znacznie więcej niż uzyskane w przypadku He implantowanego do Ge.

EN

Thermal desorption of Ar implanted into germanium (with energies 100 keV and 150 keV, fluence 2×1016 cm-2) was studied. Sudden release of Ar was observed as narrow peaks in temperature range 790-840 K in TDS spectra, which may be assigned to the release of gas trapped as bubbles in cavities in the Ge lattice. The analysis of peak shifts enabled estimation of desorption activation energies - it is 3.2 eV (100 keV) and 2.2 eV (150 keV) - these values are much larger than those measured for He implanted into Ge.

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Modyfikacja właściwości folii PET przy wykorzystaniu naświetlania jonami K+

Turek Marcin, Droździel Andrzej, Pyszniak Krzysztof, Grudziński Wojciech, Klimek-Turek Anna

Przegląd Elektrotechniczny

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2020

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R. 96, nr 8

151--155

PL

Cienkie (3 m) folie PET implantowano jonami K+ (150 keV, dawki 1014 cm-2, do 1016 cm-2. Zaobserwowano niszczenie różnego rodzaju wiązań chemicznych i powstanie struktur grafitopodobnych a także wzrost absorbancji modyfikowanych próbek w widmie UV-VIS oraz zwężenie przerwy energetycznej z około 4 eV aż do 0.55 eV (1016 cm-2). Implantacja spowodowała spadek oporności powierzchniowej warstwy zmodyfikowanej o około 6 rzędów wielkości oraz wzrost stałej dielektrycznej folii: od kilku procent dla dawki 1014 cm-2 do ~65 % dla dawki 1016 cm-2.

EN

Thin (3 m) PET foils were implanted with K+ ions (150 keV, fluences from 1014 cm-2 to 1016 cm-2). Destruction of various chemical bonds and formation of graphite-like structures as well as the increase of absorbance in UV-VIS spectra and narrowing of the energy bandgap from ~4 eV to 0.55 eV (1016 cm-2) were observed. Ion implantation leads to the reduction of sheet resistance by 6 ordes of magnitude as well as to the increase of dielectric constant of the sample by several percent (1014 cm-2) up to 65 % for the maximal fluence.

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Comparing of Microhardness of the Stellite 6 Cobalt Alloy Implanted with 175 keV Mn+ Ions and 120 keV N+ Ions

Kamiński Mariusz, Budzyński Piotr, Szala Mirosław, Turek Marcin

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 3

179--185

EN

Nowadays, high-precision machines require lightweight materials with very high strength. Ion implantation is used to improve the mechanical strength of the material. A further paper presents the influence of manganese and nitrogen ion implantation on changes of microhardness of the surface layer of cobalt alloy. Samples were analyzed with the SEM-EDS Phenom ProX microscope. Microhardness was assessed with the Vickers method, and the loads of 1 gf (0.00981 N) and 5 gf (0.049 N) was applied using a FM-800 from Future-Tech microhardness meter. At a load of 1 gf, the penetration depth of the implanted specimens was reached not exceeding 0.5 um. At this depth, all samples showed an increase in microhardness compared to the unimplanted sample. The highest increase in microhardness was achieved after implantation of Mn ions with dose D=1∙1017 Mn+/cm2 and energy E=175 keV. The increased load on the indenter to 5 gf reduced the microhardness differences between implanted and unimplanted samples.