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Enhancing Fatigue Performance of Additively Manufactured Ti6Al4V – The Role of Surface Characteristics and Post-Processing Techniques

Kurek Andrzej, Żrodowski Łukasz, Choma Tomasz, Abramczyk Izabela, Kłonica Mariusz, Wachowski Marcin

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 6

280--290

EN

Geometrically complex objects are more and more often produced with the help of the so-called additive manufacturing commonly referred to as 3D printing. This technology proves itself to be effective in the field of medical industry due to processing potential of titanium alloys. Nonetheless 3D printing also has its drawbacks, the most severe being high roughness of printed elements’ area as well as the need to remove support structures created following the printing. Mechanical processing is commonly used for said parameters being enhanced. The completion of that process, however, takes a lot of time and prevents hard-to-reach elements from being reached. The task of this article is to provide a new method of firming the print’s surface and removing load-bearing structures. To achieve this, selective laser melting (SLM) technology will be used along with bathing prints in HF/HNO3 solution, all of which are supported by ultrasound.

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Studies of the microstructure of bimetallic titanium – austenitic steel joints obtained by explosive welding

Wachowski Marcin, Kosturek Robert

Materiały Wysokoenergetyczne

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2023

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T. 15

15--23

EN

The specific requirements of installations used in the chemical and petrochemical industries require materials with high corrosion resistance and adequate strength. Materials with these characteristics can be obtained by explosive cladding technology. Results of studies of the microstructure of titanium-austenitic steel 304L bimetallic joints in the welded and heat-treated condition are presented. Applications for this type of material include heat exchanger tube surfaces exposed to aggressive environments with high cyclical mechanical loads. The joints were tested using an optical microscope and a scanning electron microscopy. Heat treatment has contributed to a decrease in microhardness near the joint, which demonstrates a reduction in the strain hardening in this area.

PL

Szczególne wymagania instalacji stosowanych w przemyśle chemicznym i petrochemicznym powodują konieczność stosowania materiałów o dużej odporności korozyjnej oraz odpowiedniej wytrzymałości. Materiały spełniające te wymagania można wytworzyć technologią platerowania wybuchowego. W pracy przedstawiono wyniki badań mikrostruktury złączy bimetalicznych tytan-stal austenityczna 304L w stanie po zgrzewaniu i po obróbce cieplnej. Aplikacją tego typu materiałów są m.in. ściany sitowe wymienników ciepła, które narażone są na pracę w agresywnym środowisku, przy wysokich cyklicznych obciążeniach mechanicznych. Złącza badano z wykorzystaniem mikroskopu świetlnego oraz skaningowej mikroskopii elektronowej. Obróbka cieplna przyczyniła się do spadku mikrotwardości w pobliżu złącza, co świadczy o redukcji strefy umocnienia występującej w tym obszarze.

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Research on the post-weld explosive hardening of AA7075-T651 friction stir welded butt joints

Kosturek Robert, Lewczuk Rafał, Torzewski Janusz, Wachowski Marcin, Słabik Piotr, Maranda Andrzej

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 4

art. no. e145685

EN

In this paper, the post-weld explosive hardening of a 5 mm AA7075-T651 plate welded via FSW was performed. To investigate the possibility of increasing FSW joint mechanical properties, the welded plate was explosively treated with four various explosive materials (ammonal, emulsion explosive, FOX-7, and PBX) in two different hardening systems. As part of the investigation, the observations of the surface and macrostructure of the treated plates were described. The obtained microhardness distribution allowed us to register the increase in hardness of the SZ up to 6%, but no increase in hardness of the LHZ was reported. In most cases, the influence of explosive treatment on the mechanical properties of the welded joint was disadvantageous as ultimate tensile strength and ductility were reduced. The only positive effect which was observed is the increase in the value of yield strength up to 27% corresponding to 77 MPa, achieved by explosive materials with detonation velocity below 3000 m/s.

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Mechanical properties of titanium grade 1 after laser shock wave treatment

Hutsaylyuk Volodymyr, Wachowski Marcin, Kovalyuk Bogdan, Mocharskyi Vitalii, Sitkar Oksana, Śnieżek Lucjan, Zygmuntowicz Justyna

Advances in Materials Science

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2023

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Vol. 23, nr 4(78)

48--61

EN

In the presented work the impact of a laser shock wave on the mechanical properties of a Titanium Grade 1 was investigated. Based on a series of experimental studies related to the impact of the laser shock wave on the tested material, the impact of the given treatment on the structure and mechanical properties was assessed. The influence of the environment on the distribution of plasma temperature and pressure in the material during the implementation of the laser shock wave was analyzed. The effect of the laser treatment on the structure and micromechanical properties was initially estimated on the basis of the analysis of experimental results in the form of static strength testof samples after laser treatment. A slight increase in material strength was detected with a minimal decrease in ductility. In order to comprehensively understand the observed phenomenon, a number of fractographic tests were performed, especially the analysis of the porosity of the fracture surfaces. A decrease in the porosity of the material after impact laser treatment was observed as a result of local plastic deformation.

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Research on the Microstructure of Laser Beam Welded Sc-Modified AA2519-F Extrusion

Kosturek Robert, Śnieżek Lucjan, Grzelak Krzysztof, Wachowski Marcin

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 2

773--778

EN

In this paper, the microstructure of laser beam welded Sc-modified AA2519-F has been taken under investigation. The welded joint has been produced using Fanuc 710i industrial robot equipped with YLS-6000 6 kW laser beam source. The welding speed and laser power were equal to 0.75 m/min and 3.2 kW, respectively. The investigation involved microstructure observations with the use of both light microscope and scanning electron microscope with energy dispersive spectroscopy (EDS) analysis of chemical composition and microhardness distribution measurements. It has been stated that laser beam welding allows to obtain Sc-modified AA2519-F weld of good quality, characterized by the presence of an equiaxed grain zone containing scandium-rich precipitates adjacent to the fusion boundary.

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Microstructure and mechanical properties of Sc-modified AA2519-T62 laser beam welded butt joints

Kosturek Robert, Grzelak Krzysztof, Torzewski Janusz, Wachowski Marcin, Śnieżek Lucjan

Advances in Materials Science

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2022

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Vol. 22, nr 4(74)

57--69

EN

The fundamental aim of the research is to investigate the microstructure and mechanical properties of the AA2519-T62 laser beam welded joints obtained with various values of welding velocity. For the constant value of laser power (3.2 kW) three joints have been produced with various values of welding velocity: 0.8, 1.1, and 1.4 m/min. The joints have been subjected to microstructure analysis (including both light and scanning electron microscope), microhardness measurements, tensile tests, and fractography of tensile samples. The established values of joint efficiency contain within the range of 55-66% with the highest value (66%) reported for the joint obtained with 1.1 m/min welding velocity. The produced welds have noticeable participation of pores, which tends to increase together with the value of welding velocity. In all cases, the failure has occurred in the fusion zone by ductile fracture.