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Materiały na elementy złączne po wysokociśnieniowej przeróbce plastycznej

100%

Kulczyk M. , Skiba J. , Radomski P.

Fastener : rynek elementów złącznych

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2020

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tom nr 2

26--30

PL

W pracy przedstawiono ogólną charakterystykę wysokociśnieniowej przeróbki plastycznej metali i stopów metali metodą wyciskania hydrostatycznego. Opisano zalety procesu ze szczególnym uwzględnieniem możliwości rozdrabniania struktury metali i stopów metali do poziomu nanometrycznego lub ultradrobnoziarnistego, skutkującego znacznym podniesieniem ich właściwości mechanicznych. Pokazano przykłady praktycznego zastosowania przerabianych plastycznie metali, tj. tytanu oraz stopu aluminium AA5083 na elementy złączne.

2

Texture, residual stresses and mechanical properties analysis in the commercial 1.4462 duplex stainless steel subjected to hydrostatic extrusion

100%

Zdunek J. , Maj P. , Kulczyk M. , Mizera J.

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2019

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tom Vol. 19, no. 2

525--534

EN

In the current research the hydrostatic extrusion (as one of the most common method of grain refinement) of the commercial 1.4462 duplex stainless steel was carried out using several reduction stages leading to a cumulative deformation strain ɛ = 1.4, and then ɛ = 3.8. The extrusion process has led to a change of microstructure and texture of the investigated material as was expected. Moreover, these changes were accompanied by improvements in mechanical properties measured by the nanohardness. The aim of this research was the characterization of the texture, residual stress and mechanical properties after subsequent stages of deformation.

3

Fastener materials after high-pressure forming

100%

Kulczyk M. , Skiba J. , Radomski P.

Fastener : rynek elementów złącznych

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2021

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tom nr 1

52--55

EN

This paper presents general characteristics of high-pressure forming of metals and metal alloys with the use of hydrostatic extrusion method. It describes the advantages of the process with particular attention paid to the possibility of refining the structure of metals and metal alloys to a nanometric or ultra-fine level resulting in significant improvement of their mechanical properties. It shows the examples of practical application of formed metals, namely titanium and aluminium alloy AA5083, in the manufacture of fastening elements.

4

Anisotropy of structural and mechanical properties in CuCrZr alloy following hydrostatic extrusion process

100%

Przybysz S. , Kulczyk M. , Skiba J. , Skorupska M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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tom Vol. 70, nr 4

art. no. e141725

EN

The methods of severe plastic deformation (SPD) of metals and metal alloys are very attractive due to the possibility of refinement of the grains to nanometric sizes, which facilitates obtaining high mechanical properties. This study investigated the influence of SPD in the process of hydrostatic extrusion (HE) on the anisotropy of the mechanical properties of the CuCrZr copper alloy. The method of HE leads to the formation of a characteristic microstructure in deformed materials, which can determine their potential applications. On the longitudinal sections of the extruded bars, a strong morphological texture is observed, manifested by elongated grains in the direction of extrusion. In the transverse direction, these grains are visible as equiaxed. The anisotropy of properties was mainly determined based on the analysis of the static mini-sample static tensile test and the dynamic impact test. The obtained results were correlated with microstructural observations. In the study, three different degrees of deformation were applied at the level necessary to refine the grain size to the ultrafine-grained level. Regardless of the applied degree of deformation, the effect of the formation of a strong morphological texture was demonstrated, as a result of which there is a clear difference between the mechanical properties depending on the test direction, both by the static and dynamic method. The obtained results allow for the identification of the characteristic structure formed during the HE process and the more effective use of the CuCrZr copper alloy in applications.

5

Effects of HE and ECAP processes on changes in microstructure and mechanical properties in copper, iron and zinc

88%

Kulczyk M. , Skorupska M. , Skiba J. , Przybysz S. , Smalc-Koziorowska J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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tom Vol. 71, nr 3

art. no. e145563

EN

The research presented in this paper concerns the influence of the rate of plastic deformation generated directly in the processes of severe plastic deformations on the microstructure and properties of three metals: copper, iron and zinc. The equal channel angular pressing (ECAP) method was used, and it was performed at a low plastic deformation rate of ∼ 0.04 s−1. The high plastic strain rate was obtained using the hydrostatic extrusion (HE) method with the deformation rate at the level of ∼ 170 s−1. For all three tested materials different characteristic effects were demonstrated at the applied deformation rates. The smallest differences in the mechanical properties were observed in copper, despite the dynamic recrystallization processes that occurred in the HE process. In Armco iron samples, dynamic recovery processes in the range of high plastic deformation rates resulted in lower mechanical properties. The most significant effects were obtained for pure zinc, where, regardless of the method used, the microstructure was clearly transformed into bimodal after the ECAP process, and homogenized and refined after the HE process. After the HE process, the material was transformed from a brittle state to a plastic state and the highest mechanical properties were obtained.

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Unconventional methods of manufacturing thin wires for application as input material in additive manufacturing. Part 1: Preparation of input material for wire drawing

75%

Burdek M. , Garbarz B. , Woźniak D. , Adamczyk M. , Skiba J. , Kulczyk M.

Journal of Metallic Materials

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2022

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tom Vol. 74, no. 3-4

14--23

EN

Part 1 of the article presents the technological path of producing semi-finished products for wires constituting input material in additive technologies. On the basis of the developed chemical compositions of experimental Fe-based alloys, laboratory ingots with a square section of 120×120 mm / 130×130 mm were produced, which were then hot rolled into flat bars. In order to select the physical parameters of the drawing tests, numerical modelling of the process was performed. As a result of the simulations, it was found that the calculated drawing force exceeds the capabilities of the experimental drawing machine and for this reason, hydrostatic extrusion was used to produce bars intended for drawing wires. The hydrostatic extrusion method was used to make bars with a diameter of 5 mm from three tested materials, while three experimental steels showed insufficient susceptibility to extrusion at high pressure and cracked at various strain values. An analysis of possible causes of bar breakage during extrusion was carried out on the basis of the results of microstructure examination.

PL

W części 1 artykułu przedstawiono ścieżkę technologiczną wykonania półwyrobów przeznaczonych na druty będące materiałem wsadowym do technologii przyrostowych. Na podstawie opracowanych składów chemicznych eksperymentalnych stopów na bazie Fe wytworzono wlewki laboratoryjne o przekroju kw. 120×120 mm / 130×130 mm, które następnie poddano walcowaniu na gorąco na płaskowniki. W celu dobrania parametrów fizycznych testów ciągnienia wykonano modelowanie numeryczne tego procesu. W wyniku symulacji ustalono, że wyliczona siła ciągnienia przewyższa możliwości eksperymentalnej ciągarki i z tego powodu do wytworzenia prętów przeznaczonych do ciągnienia drutów zastosowano wyciskanie hydrostatyczne. Metodą wyciskania hydrostatycznego wykonano pręty o średnicy 5 mm z trzech badanych materiałów, natomiast trzy eksperymentalne stale wykazały niewystarczającą podatność do wyciskania z wysokim ciśnieniem i ulegały pękaniu przy różnych wartościach odkształcenia. Przeprowadzono analizę możliwych przyczyn pękania prętów w trakcie wyciskania na podstawie wyników badań mikrostruktury.