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Maj P.♦, Bochenek K., Sitek R.♦, Koralnik M.♦, Jonak K.♦, Wieczorek M.♦, Pakieła Z.♦, Mizera J.♦, Comparison of mechanical properties and structure of Haynes 282 consolidated via two different powder metallurgy methods: laser powder bed fusion and hot pressing,
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1007/s43452-023-00674-y, Vol.23, No.130, pp.1-11, 2023Streszczenie: The development of powder metallurgy methods in recent years has caused traditional casting methods to be replaced in many industrial applications. Using such methods, it is possible to obtain parts having the required geometry after a process that saves both manufacturing costs and time. However, there are many material issues that decrease the functionality of these methods, including mechanical properties anisotropy and greater susceptibility to cracking due to chemical segregation. The main aim of the current article is to analyze these issues in depth for two powder metallurgy manufacturing processes: laser powder bed fusion (LPBF) and hot-pressing (HP) methods—selected for the experiment because they are in widespread use. Microstructure and mechanical tests were performed in the main manufacturing directions, X and Z. The results show that in both powder metallurgy methods, anisotropy was an issue, although it seems that the problem was more significant for the samples produced via LPBF SLM technique, which displayed only half the elongation in the building direction (18%) compared with the perpendicular direction (almost 38%). However, it should be noted that the fracture toughness of LPBF shows high values in the main directions, higher even than those of the HP and wrought samples. Additionally, the highest level of homogeneity even in comparison with wrought sample, was observed for the HP sintered samples with equiaxed grains with visible twin boundaries. The tensile properties, mainly strength and elongation, were the highest for HP material. Overall, from a practical standpoint, the results showed that HP sintering is the best method in terms of homogeneity based on microstructural and mechanical properties. Słowa kluczowe: Haynes 282 nickel alloy, LPBF, HP, SEM , Static tensile test Afiliacje autorów:
Maj P. | - | Politechnika Warszawska (PL) | Bochenek K. | - | IPPT PAN | Sitek R. | - | Politechnika Warszawska (PL) | Koralnik M. | - | inna afiliacja | Jonak K. | - | inna afiliacja | Wieczorek M. | - | inna afiliacja | Pakieła Z. | - | Politechnika Warszawska (PL) | Mizera J. | - | Politechnika Warszawska (PL) |
| | 140p. |
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Chmielewski M.♦, Nosewicz S., Jakubowska D.♦, Lewandowska M.♦, Mizera J.♦, Rojek J., Bazarnik P.♦, The influence of sintering time on the microstructural properties of chromium-rhenium matrix composites,
International Journal of Refractory Metals and Hard Materials, ISSN: 0263-4368, DOI: 10.1016/j.ijrmhm.2016.05.017, Vol.59, pp.78-86, 2016Streszczenie: This paper comprises the results of studies of the changes in the structure of Cr-Re-Al2O3 metal matrix depending on heat treatment time in sintering temperature. The density of material with the following composition: 95%(75%Cr-25%Al2O3)+5%Re was increased using the technique of sintering under pressure (30MPa) at the temperature of 1450°C. As a result, materials characterized by a high relative density (< 97% of theoretical density) were obtained. Next, they were subjected to structural tests including scanning and transmission electron microscopy as well as X-ray diffraction. Changes in the phase composition, grains size and parameters of crystallographic structure depending on heat treatment time were analysed. It was found that during sintering rhenium is dissolved in the chromium matrix and Cr-Re solid solution is formed. When sintering time is extended to 120 min, the matrix of the composite becomes completely homogenous, which results in an increased strength of the composite. Słowa kluczowe: Metal matrix composites, Rhenium, Hot pressing, Microstructure analysis, XRD Afiliacje autorów:
Chmielewski M. | - | Institute of Electronic Materials Technology (PL) | Nosewicz S. | - | IPPT PAN | Jakubowska D. | - | inna afiliacja | Lewandowska M. | - | inna afiliacja | Mizera J. | - | Politechnika Warszawska (PL) | Rojek J. | - | IPPT PAN | Bazarnik P. | - | Politechnika Warszawska (PL) |
| | 35p. |
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Pawełek A.♦, Piątkowski A.♦, Kuśnierz J.♦, Bogucka J.♦, Jasieński Z.♦, Ranachowski Z., Ranachowski P., Mizera J.♦, Kúdela S.♦, Kúdela Jr S.♦, Acoustic emission in compressed Mg - Li and Al. alloys processed by ECAP, HPT and ARB methods,
ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.32, No.4, pp.88-94, 2007 | |