Wyniki wyszukiwania - Biblioteka Nauki

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Laser Powder Bed Fusion and Selective Laser Melted Components Investigated with Highly Penetrating Radiation

100%

Gadalińska E. , Pawliszak Ł. , Moneta G.

Fatigue of Aircraft Structures

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2021

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tom Iss. 13

81--98

EN

Methods of incremental manufacturing, i.e. 3D printing, have been experiencing significant growth in recent years, both in terms of the development of modern technologies dedicated to various applications, and in terms of optimizing the parameters of the process itself so as to ensure the desired mechanical and strength properties of the parts produced in this way. High hopes are currently being pinned on the use of highly penetrating types of radiation, i.e. synchrotron and/or neutron radiation, for quantitative identification of parameters characterizing objects produced by means of 3D printing. Thanks to diffraction methodologies, it is feasible to obtain input information to optimize 3D printing procedures not only for finished prints but also to monitor in situ printing processes. Thanks to these methodologies, it is possible to obtain information on parameters that are critical from the perspective of application of such obtained elements as stresses generated during the printing procedure itself as well as residual stresses after printing. This parameter, from the point of view of tensile strength, compression strength as well as fatigue strength, is crucial and determines the possibility of introducing elements produced by incremental methods into widespread industrial use.

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Comparison of mechanical properties and structure of Haynes 282 consolidated via two different powder metallurgy methods: laser powder bed fusion and hot pressing

94%

Maj P. , Bochenek K. , Sitek R. , Koralnik M. , Jonak K. , Wieczorek M. , Pakieła Z. , Mizera J.

Archives of Civil and Mechanical Engineering

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2023

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tom Vol. 23, no. 2

art. no. e130, 2023

EN

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.

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Process parameters effect on porosity rate of AlSi10Mg parts additively manufactured by Selective Laser Melting: challenges and research opportunities

84%

Kiass E. M. , Zarbane K. , Beidouri Z.

Archives of Materials Science and Engineering

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2023

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tom Vol. 122, nr 1

22--33

EN

Purpose: The present study aims to conduct a literature review on the various methods explored to enhance the quality of AlSi10Mg parts manufactured via the Selective Laser Melting (SLM) process. Specifically, the research focuses on identifying strategies for reducing the porosity level in SLM-fabricated AlSi10Mg parts. Considering the highly competitive nature of the market in which SLM technology is employed, improving part quality is necessary to ensure business continuity and maintain a competitive edge. Design/methodology/approach: The present study offers a comprehensive examination of the SLM process, particularly emphasising the diverse parameters that can influence the porosity rate in SLM-fabricated parts. By providing a detailed description of the SLM process, we highlight the intricacy of this technology and discuss the significance of various parameters. Furthermore, we present a literature review of prior research on SLM, summarising the studied parameters and their impact on porosity. This research aims to enhance our understanding of the SLM process and the parameters that affect the density of SLM-fabricated parts. Findings: The present study aims to identify research opportunities in the field of SLM technology. One particularly promising area of investigation is exploring the correlation between scan direction and the porosity rate in SLM-fabricated parts. This research seeks to enhance our understanding of the relationship between these two parameters and their potential impact on the quality of SLM-fabricated parts. Practical implications: By reducing porosity, industries such as aerospace and aeronautics can attain enhanced performance through mechanical system optimisation. Originality/value: The present study summarises the various methods previously investigated for reducing the porosity rate in parts manufactured using the SLM process. Additionally, it proposes new avenues for achieving further parameter optimisation to attain higher levels of quality.

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Development of Diffraction Research Methodologies for Mediloy S-CO Alloy Speciments Made Using LPBF Additive Manufacturing

84%

Gadalińska E. , Malicki M. , Trykowska A. , Moneta G.

Fatigue of Aircraft Structures

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2023

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tom Iss.15

90--114

EN

This study focuses on the application and improvement of diffraction measurement methodologies for the optimization of manufacturing parameters of CoCr alloy components made by additive manufacturing (AM) - particularly for Mediloy S-Co alloy specimens made using Laser Powder Bed Fusion (LPBF) additive manufacturing. We measured the phase composition of specimens obtained in AM processes, the measurement of residual stresses resulting from the manufacture of these printed parts, as well as the effectiveness of stress relaxation through the use of heat treatments dedicated to this type of material. Findings reveal several insights into how printing strategies affect the porosity and residual stresses in additive manufacturing. Specimens with higher porosity, particularly those created using specific strategies that resulted in lower energy densities, exhibited lower residual stresses. Notably, printing direction and energy density were found to significantly affect the mechanical stresses within the specimens, with directional choices playing a critical role in the final properties of the parts. Additionally, our findings underscore the complex relationship between various printing parameters and the development of mechanical stresses, highlighting the impact of adjustments in printing strategy on the properties of printed components.