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1

Selected microstructural phenomena in FSW joints

Wciślik Wiktor

Structure and Environment

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2024

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Vol. 16, no. 2

97--110

EN

The article is a literature review on selected phenomena leading to microstructural changes in material welded using the friction stir welding (FSW) method. Particular attention was paid to the phenomena of grains recrystallization, as well as dissolution and reprecipitation of second phase particles, resulting from temperature changes during FSW. Temperature transformations in different zones of the FSW joints were characterized. The role of base material phase transformation in the formation of new particles is discussed. In the tested aluminum alloys and stainless steels, this process was particularly intensified in the heat affected zone (HAZ). In areas subjected to high temperature and significant plastic deformation (nugget zone and thermomechanically affected zone), this phenomenon did not occur or was characterized by small intensity. It was indicated that the phenomenon of particle formation clearly affects the strength parameters of the joint.

PL

W artykule przedstawiono przegląd literatury dotyczący wybranych zjawisk prowadzących do zmian mikrostrukturalnych w metalach spawanych metodą zgrzewania tarciowego (FSW). Szczególną uwagę zwrócono na zjawiska rekrystalizacji ziaren oraz rozpuszczania i ponownego wytrącania cząstek drugiej fazy, zachodzące jako efekt zmian temperatury podczas FSW. Scharakteryzowano zmiany temperatury w różnych strefach złączy FSW. Omówiono rolę przemian fazowych materiału podstawowego w powstawaniu nowych cząstek. W badanych stopach aluminium i stalach nierdzewnych proces ten był szczególnie nasilony w strefie wpływu ciepła (SWC). W obszarach narażonych na działanie wysokiej temperatury i znacznych odkształceń plastycznych (jądro zgrzeiny i strefa uplastycznienia termomechanicznego) zjawisko to nie występowało lub charakteryzowało się niewielkim natężeniem. Wykazano, że zjawisko tworzenia cząstek wyraźnie wpływa na parametry wytrzymałościowe złącza.

2

Wykonywanie połączeń różnoimiennych ze stopów aluminium metodami spawania łukowego i FSW

Węglowska Aleksandra, Rykała Janusz, Pfeifer Tomasz, Pietrzak Jacek

Maszyny Elektryczne : zeszyty problemowe

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2023

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Nr 1 (128)

103--107

PL

Przedstawiono wyniki badań spawania TIG i MIG oraz zgrzewania FSW złączy z blach ze stopu aluminium EN AW6082, EN AW 5754 oraz odlewniczego stopu EN AC-43200. Scharakteryzowano stopy Al-Mg oraz Al-Mg-Si i ich spawalność. W ramach realizowanych badań przeprowadzono dobór warunków spawania i zgrzewania różnoimiennych stopów aluminium. Złącza poddano badaniom wizualnym, metalograficznym makroskopowym, penetracyjnym (złącza spawane) oraz własności mechanicznych w statycznej próbie rozciągania i zginania (złącza zgrzewane FSW). Na podstawie wyników badań realizowanych w Łukasiewicz – GIT oceniono, że jakość złączy spawanych zależy od przygotowania elementów do spawania, natomiast złączy zgrzewanych od parametrów zgrzewania i ustawienia stopów Al w złączu względem ruchu obrotowego narzędzia.

EN

Results of TIG, MIG and FSW welding technologies of joints made of EN AW-6082, EN AW 5754 aluminum alloy sheets and EN AC-43200 casting alloy are presented. This article briefly presents the characteristics of Al-Mg and Al-Mg-Si alloys and their weldability. As part of the research welding conditions for dissimilar aluminum alloys were selected. The joints were subjected to the visual and penetrant tests (TIG, MIG joints), light microscopy examination as well as tensile and bend tests (FSW joints). Based on the test results obtained in Łukasiewicz – GIT, it was found that the quality of arc welded joints depends on the preparation of the elements for welding, while the quality of FSW joints depends on the welding parameters and the positioning of Al alloys in the joint in relation to the rotational movement of the tool.

3

The Effect of Different Conditions on the Tensile Properties of AA7075-T6 During the Friction Stir Welding Process

Sharma Akash, Dwivedi Vijay Kumar, Singh Yesh Pal

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

813--821

EN

In this paper the investigation of the FSW result characteristics on AA7075-T6 of the highest grade is carried out using different process parameters. A vertical milling machine with different FSW tool geometry is used to weld AA7075. When the tool rotational speed varies from 1200 and 1800 (rpm), different welding parameters are studied, the plunge depth of tool is between 0.14 and 0.20 mm, the table transverse speed range is between 20 and 50 (mm/min) and the tool shoulder diameter was 20 mm. The welding settings are optimized using the Taguchi approach. In this experimental investigation Taguchi Technique is utilized in this study to optimize three factorial and three level designs. The results show that when the rotating speed increases, the UTS of the welded joint increases, whereas the tensile strength of the welded joint decreases resulting to frictional heat created during the FSW process. Tensile strength decreases as feed increases and increases as rotational speed increases. For a 5 mm thick plate, tensile strength is optimal with a tool shoulder diameter of 20 mm, a rotational speed of 1600 rpm, feed rate of 30 mm/min and plunge depth. The shoulder diameter of 20 mm provides the maximum ultimate tensile strength when it is compared with all other tool shoulder diameter. The Al alloy AA7075-T6 plates, however, concurrently developed an equiaxial grain structure with a substantially smaller grain size and coarsened the precipitates.

4

Study on Microstructure and Mechanical Properties of Friction Stir Welding Joints of In-Situ Al3Zr/AA6082 Particle-Reinforced Aluminum Matrix Composites

Li Hui, Sun Caizhi, Wang Feng, Qiao Yuanpeng, Li Chuying, Xu Pinyi, Zatulovskiy Andrii, Shcheretskyi Volodymyr

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

907--919

EN

In this paper, the Al-K2ZrF6 reaction system was used to prepare in-situ Al3Zr/AA6082 particle-reinforced aluminum matrix composites by electromagnetic stirring melt reaction method, and the friction stir welding technology was used to weld the plate. The microstructure and mechanical properties of the welded joints were studied when the rotating speed was 14000 rpm and the welding speed was 30, 50 and 70 mm/min respectively. The results show that the weld forming quality and tensile properties of the FSW joints with welding parameters of 14000 rpm and 50 mm/min are the best, the tensile strength is 142(±0.5) MPa and the elongation is 8.2%. SEM analysis shows that the particle size of the reinforcing phase in the base metal is refined to about 5-10 μm, while that in the NZ is about 1-5 μm. The grain size in the HAZ is about 20-30 μm and in the NZ is about 5-10 μm. EBSD analysis shows that the proportion of low-angle grain boundary in the NZ is 59.7% and of recrystallized grain structure is 23.65%, while the proportion of small-angle grain boundary in the HAZ is 24.35% and of recrystallized grain structure is 37.18%. It provides theoretical and experimental basis for the forming and application of friction stir welding of the composite.

5

The Effect of Brushing on Residual Stress and Surface Roughness of EN AW-2024-T3 Aluminum Alloy Joints Welded Using the FSW Method

Bucior Magdalena, Kluz Rafał, Kubit Andrzej, Ochał Kamil

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 1

86--93

EN

This article presents the influence of the brushing process on residual stress and surface roughness of EN AW-2024-T3 aluminum alloy joints welded using the Friction Stir Welding (FSW) method. Butt joints with thicknesses of 2 mm were brushing with using ceramic brush. The aim of the study was to find optimal parameters of the brushing process, which would significantly improve the functional properties of welded joints. The experiments were carried out in two steps. In the first stage of the research, the feed rate was changed in the range f = 40 ÷ 120 mm / min with a constant brushing depth d = 0.5 mm. The roughness decreased from Sa = 5.285 µm for the specimen after welding to Sa = 2.460 µm for the f = 120 mm/min and d = 0.5 mm. The change in the parameters of the brushing process did not have a significant impact on the state of residual stresses. Hence, in the second step, the brushing depth was increased in steps of 0.1 mm. The best properties were obtained for f = 120 mm / min and d = 0.6 mm (variant 6A), where roughness was Sa = 0.443 µm and compressive stresses σ = -118 MPa.

6

Investigating the FSW parameter’s role on microstructure and mechanical properties of welding AZ31B–AA8110 alloy

Dharmalingam S., Lenin K., Srinivasan D.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 1

art. no. e140098

EN

The influence of friction stir welding (FSW) in automotive applications is significantly high in recent days as it can boast beneficial factors such as less distortion, minimized residual stresses and enhanced mechanical properties. Since there is no emission of harmful gases, it is regarded as a green technology, which has an energy efficient clean environmental solid-state welding process. In this research work, the FSW technique is employed to weld the AA8011–AZ31B alloy. In addition, the L16 orthogonal array is employed to conduct the experiments. The influences of parameters on the factors such as microstructure, hardness and tensile strength are determined. Microstructure images have shown tunnel formation at low rotational speed and vortex occurrence at high rotational speed. To attain high quality welding, the process parameters are optimized by using a hybrid method called an artificial neural network based genetic algorithm (ANN-GA). The confirmation tests are carried out under optimal welding conditions. The results obtained are highly reliable, which exhibits the optimal features of the hybrid method.

7

Extended friction stir welding applications and the use of an innovative FSW head

Nowak Mirosław, Szostek Paweł, Nowak Marcin

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2022

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Vol. 66, No. 5

61--72

EN

The article presents general information about friction stir welding process (FSW) as a welding method involving the stirring of the weld material, discusses the course of the welding process itself, describes the structure of the FSW joint, presents advantages and disadvantages of the method as well as discusses factors affecting the quality of FSW joints. In addition, the article describes an innovative FSW head (designed by Stirweld (France) and installed on CNC machines) as well as illustrates the operation of the head and enumerates the advantages resulting from the use of the head in comparison with those characteristic of “conventional” friction stir welding machines.

PL

W artykule przedstawiono ogólne informacje na temat metody zgrzewania z mieszaniem materiału zgrzeiny FSW (Friction Stir Welding). Scharakteryzowano przebieg procesu zgrzewania, opisano budowę złącza, przedstawiono i omówiono wady oraz zalety metody, a także czynniki wpływające na jakość połączeń. W publikacji opisano innowacyjną głowicę do zgrzewania FSW firmy Stirweld (Francja), instalowaną na frezarkach CNC. Zilustrowano proces działania głowicy oraz omówiono korzyści wynikające z jej zastosowania w porównaniu ze zgrzewarkami FSW.

8

Fabrication of longitudinal welded tube of aluminum alloy for structural application using friction stir welding process and its characterization

Sen Debolina, Pal Surjya Kanta, Panda Sushanta Kumar

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 2

art. no. e91, 1--21

EN

Thin-walled aluminum alloy tubes used for structural applications can be produced by various processes among which friction stir welding process (FSW) has emerged rapidly due to its superior welded properties. But, FSW of tubular components is complex due to its curvature which makes it challenging to get the desired quality of the tube. Hence, in the present study, an attempt was made to fabricate longitudinal FSWed tubes of AA5083-O alloy. A novel parameter window highlighting their effects on the weld quality was presented, and the significant process parameters were optimized to get a defect-free good-quality welded tube. In this regard, X-ray micro-computed tomography, hardness and uniaxial tensile tests of the weld zone (WZ) were carried out to assess the weld quality. Negligible amount of porosity was observed in the WZ, and the hardness was comparable to that of the base material. The joint efficiency obtained was 87%, suggesting homogeneity of the WZ. To get further insight into the WZ homogeneity, the failure mechanism along with the microscopic damage initiation characteristic of the tensile samples was studied. Failure of these samples took place in between the nugget zone and the thermo-mechanically affected zone, and a mixed type of fracture was observed. Three types of void nucleation mechanisms viz., inclusion or particle cracking, interface debonding, and matrix cracking coexisted in the welded sample among which particle cracking was the most significant. Also, the surface roughness of the WZ was measured and it was observed that the material flow during the welding process affected the average roughness value.

9

Relation between geometry of FSW tools and formation of nano- dispersed zones in macrostructure EN AW 6082-T6 alloy welded joints

Krasnowski Krzysztof, Khokhlova Julia, Khokhlov Maksym, Kostin Valery

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2021

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Vol. 65, No. 5

7--16

EN

An article present the result of macrostructure formation with distribution of mechanical properties in cross-sections of 8 mm-thick one-sided butt-welded FSW joints of EN AW 6082-T6 alloy which were obtained using three types of specially designed tools: C-type – conventional tool consisting of a housing, cylindrical threaded probe and a shoulder with a grooved spiral, T-type – Triflute-type tool consisting of a housing, cylindrical threaded probe with three grooves and a shoulder with a grooved spiral, S-type – simple tool consisting of a housing, smooth cylindrical probe without a thread and a flat shoulder. Friction stir welding was performed using equipment of the Institute of Welding in Gliwice of Poland, and mechanical tests in the E.O. Paton Electric Welding Institute of the NAS of Ukraine. Mechanical test by indentation was performed using Micron-gamma device, which allows experimental identification of structural state of metal and determination of the strain hardening presence by limiting values of ratio of hardness to Young’s modulus of elasticity. It was found that for all three specimens the HAZ hardness decreases, and in the zone of thermomechanical effect the hardness increases. Maximum hardness values are inherent to the central part of welded joint nugget, as well as to light-coloured oval concentrated fragments of structure in the nugget upper and lower part. Judging by the presence of nanosized hardened structure and uniformity of its distribution in the nugget, as well as good dispersion of oxide films and absence of discontinuities, the friction stir welding with C-type tool can be regarded as the optimum variant. An assumption was made that formation of a uniform structure in welds can be achieved at three–four revolutions of the tool in friction stir welding in one place. The model of thermal fields distribution in Al-plate during FSW using a C-type tool visualized the metal’s thermal condition when formated hardened nano-dispersed weld zones.

PL

W artykule przedstawiono wyniki badań nad tworzeniem się nanostruktury z rozkładem właściwości mechanicznych w przekrojach poprzecznych złączy FSW o grubości 8 mm ze stopu EN AW 6082-T6 zgrzewanych jednostronnie doczołowo. Połączenia uzyskano przy użyciu trzech rodzajów specjalnie zaprojektowanych narzędzi. Stwierdzono, że dla wszystkich próbek twardość w SWC zmniejsza się, a w strefie oddziaływania termomechanicznego wzrasta. Maksymalne wartości twardości są charakterystyczne dla środkowej części jądra zgrzeiny, a także dla jasno zabarwionych, owalnych fragmentów w strukturze części górnej i dolnej jądra zgrzeiny. Oceniając obecność utwardzonej struktury nanometrycznej i równomierność jej rozmieszczenia w strefie zmieszania oraz dobre rozproszenie warstewek tlenkowych i brak nieciągłości, zgrzewanie tarciowe z przemieszaniem narzędziem konwencjonalnym można uznać za wariant optymalny. Można przypuścić, że podczas zgrzewania tarciowego z mieszaniem zgrzeiny uzyskuje się jednorodną strukturę zgrzein przy czterech i więcej obrotach narzędzia FSW w jednym miejscu. Model rozkładu pól termicznych w płycie aluminiowej podczas FSW, przy użyciu narzędzia konwencjonalnego, zwizualizował stan termiczny metalu podczas formowania utwardzonych stref nanodyspersyjnych w zgrzeinach.

10

Friction stir welding of wrought aluminium alloy EN AW-6082

Miara Damian

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2021

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Vol. 65, No. 4

15--24

EN

The article presents results of the friction stir welding of 6 mm thick plates made of wrought aluminium alloy EN AW-6082. Tests discussed in the article involved the identification of the effect of primary welding process parameters on the quality of welds. Test welds were subjected to visual tests, measurements of temperature (inside the weld), tensile strength tests as well as macro and microscopic metallographic tests and structural tests (performed using a scanning electron microscope). The application of the appropriate values of the primary welding process parameters (i.e. the tool rotation rate and the welding rate) enabled the obtainment of the high and repeatable quality of FSW joints made of aluminium alloy EN AW-6082. The test results presented in the article can offer technological solutions for potential users representing, among others, the railway, automotive or aviation industries.

PL

W artykule przedstawiono wyniki badań dotyczące zgrzewania metodą FSW płyt ze stopu aluminium przerabianego plastycznie EN AW-6082 o grubości 6 mm. Sprawdzono wpływ głównych parametrów procesu zgrzewania na jakość zgrzein. Przeprowadzono badania jakości zgrzein, w tym badania wizualne, pomiary temperatury wewnątrz zgrzeiny, badania: wytrzymałości zgrzein na rozciąganie oraz metalograficzne makro- i mikroskopowe, a także struktury na skaningowym mikroskopie elektronowym. Zastosowanie odpowiednich wartości głównych parametrów technologicznych zgrzewania, tj. prędkości obrotowej narzędzia oraz prędkości zgrzewania, umożliwia uzyskanie wysokiej i powtarzalnej jakości złączy FSW ze stopu aluminium EN AW-6082. Wyniki badań pozwolą opracować rozwiązanie technologiczne, które może zostać wykorzystane przez przedsiębiorców z branży kolejowej, motoryzacyjnej i lotniczej.

11

Comparative Study on Mechanical Performances of Circular and Flat Geometry Welds in Friction Stir Welding of Aluminium Alloy

Senthil S. M., Ragu Nathan Seerangan, Parameshwaran Rathinasamy, Bhuvanesh Kumar M.

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 3

881--886

EN

This study is to find the extent of variation in mechanical properties between plate and pipe welds fabricated out of the same FSW process parameters. Common thickness of 3 mm along with similar tool specifications is used to fabricate the weld. Process parameters of tool rotational speed 2000 rpm and weld speed 94 mm/min that was defined as optimal for pipe weld is used as common process parameters. Welds are analyzed for hardness and tensile properties. Yield strength and ultimate tensile strength varied about 8.1% and 11.2% respectively between plate and pipe welds. The hardness of the stir zones varied about 11.6% between plate and pipe welds.

12

A new method for measurement the residual stresses in friction stir welding

Jweeg M.J., Hamdan Z.Kh., Majeed A.H., Resan K.K., Al-Waily M.

Archives of Materials Science and Engineering

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2021

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Vol. 112, nr 2

63--69

EN

Purpose: The residual stresses in different welding methods are fundemental problems to consider. Friction stir welding is one of a solid state joining process, it is economical in that it permits joining together different materials, the specimens in this method (FSW) have excellent properties of mechanical as proven by tensile, flextural and fatigue tests, also it is environmentally friendly process minimizes consumption of energy and generate no gasses or smoke. In friction stir welding , there are two kinds of generated residual stresses: tensile stress and compressive stress. So, this study measuring the residual stresses by using a new method for measuring residual stresses depends on tensile testing and stress concentration factor, this method is a simple, fast and low cost, also it is not need special device. Design/methodology/approach: In previous studies, several techniques were used to predict the value of residual stress and its location, such as destructive, semi-destructive, and non-destructive methods. In this study, a simple, new, and inexpensive way was used based on the tensile test and stress concentration of the friction stir welding (FSW). Findings: By comparing the results obtained with the previous studies using the X-ray method, with the current research, it was found that the results are good in detecting the location and value of the residual stress of friction stir welding. The value of discrepancy of the residual stress in the results between those obtained by the previous method and the current method was about 3 MPa. Research limitations/implications: There are many rotational and linear feeding speeds used in this type of welding. This research used two plates from 6061 AA with 3mm thickness, 100 mm width, and 200 mm length. The rotational speed used in friction stir welding was 1400 rpm, and the feeding speed was 40 mm/min. Practical implications: The residual stress obtained with the new method is 6.2 MPa, and this result approximates other known methods such as the X-ray method in previus studies. Originality/value: Using a new simple method for measuring residual stresses of friction stir welding depends on stress concentration factor and tensile testing. This method is fast and low cost , also it is not need specialized device, compared to other methods such as x-ray or hole drilling methods.

13

Local binary pattern defect recognition approach for the friction stir welded AA 1200 and AA 6061-T6 aluminum alloy

Mishra Akshansh

Journal of Mechanical and Energy Engineering

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2020

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Vol. 4, No 1

27--32

EN

The research reported in this paper focuses on the application of local binary patterns (LBPs) for surface defects detection. The surface defection detection algorithm for friction stir welded aluminum plates is the key part of the entire surface defect recognition system. Two different grades i.e AA 1200 and AA 6061 plates were similarly joined with the help of Friction Stir Welding process. Python codes for the proposed algorithm were executed on Google Colaboratory platform. The results obtained prove that the local binary patterns method can be used for real-time surface defects detection in friction stir welded joints.

14

Parametric study of friction stir welding using elastic return

Serier Mohamed, Berrahou Mohamed, Chikh Amina

Archives of Mechanical Technology and Materials

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2020

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Vol. 40

7--11

EN

Aluminum alloy is a very useful material in light manufacturing. Friction stir welding (FSW) is a solid state assembly process that is achievable for this material. This work aims to characterize the quality of the weld joint by an operation of shaping (folding), it aims to study the rate of elastic return in this weld joint after a folding operation. In this context, the elastic return for the folding process has been modeled using experimental tests under optimal welding conditions.

15

Analogue modelling of flow patterns in bobbin friction stir welding by the dark-field/bright-field illumination method

Tamadon A., Pons D. J., Clucas D.

Advances in Materials Science

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2020

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Vol. 20, nr 1(63)

56--70

EN

The flow-inducing effect of the bobbin-tool features (tri-flat pin and scrolled shoulder) were replicated by a simple analogue model for aluminium welds by layered plasticine samples. Flow patterns of the weld zone were clarified by a typical stereomicroscopy instrument assisted by dark-field/bright-field illumination. The effects of the pin features, specifically threads and flats in centre of bond zone and scrolled shoulder in sides of stirred zone, were identified. This study shows that internal flow features for BFSW welds is transferable from the friction stir welding process to the functional metal forming processes such where the shearing can extensively affect the microstructure. The similarity between the flow pattern of the provided aluminium samples and the plasticine analogue can validate the accuracy of the flow model presented in this work.

16

The influence of welding method on microstructure and mechanical properties of aluminum alloys joints

Noga Piotr, Richert Maria, Węglowski Marek Stanisław

Metallurgy and Foundry Engineering

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2019

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Vol. 45, no. 2

43--50

EN

Rapid technological progress in recent years has led to an intensified interest in alternative methods of joining metals. Today’s industry is constantly demanding new joining processes, which enable high-quality welded joints in a wide range of thicknesses of combined materials at low production cost. There are at least several dozen welding methods currently available. The selection of the process depends on the type of welded materials, acceptable heat input, as well as future working conditions. The paper presents the results of the microstructural examination and mechanical properties of joints of the aluminum alloy for plastic working such as EN AW-6082. The paper presents the results of microstructural observations and mechanical properties of EN AW-6082 aluminum alloy. Methods used for joining were successively TIG (welding with a non-consumable electrode in a shield of inert gases), MIG (welding with a consumable electrode in a shield of inert gases), EBW (electron beam welding) along with FSW (friction stir welding method). TIG (welding with a non-consumable electrode in a shield of inert gases), MIG (welding with a consumable electrode in a shield of inert gases), EBW (electron beam welding) along with FSW (friction stir welding method) were used as joining techniques.

PL

Współczesny przemysł wymaga opracowania i udoskonalania metod, które umożliwiają uzyskanie wysokiej jakości połączeń w szerokim zakresie grubości łączonych materiałów oraz obniżenie kosztu produkcji. Istnieje kilkadziesiąt metod spawania. Proces ten trzeba dostosować do rodzaju spajanych materiałów, dostępnych źródeł energii, a także do przyszłych warunków pracy urządzeń. W pracy przedstawiono wyniki badań łączenia najpopularniejszego stopu do przeróbki plastycznej, jakim jest stop EN AW-6082. Metodami wykorzystanymi do łączenia były zarówno najbardziej popularne techniki spawania: TIG (spawanie elektrodą nietopliwą w osłonie gazów obojętnych), MIG (spawanie elektrodą topliwą w osłonie gazów obojętnych), metoda wysokoenergetyczna EBW (spawanie wiązką elektronową), jak również metoda zgrzewania tarciowego z mieszaniem materiały zgrzeiny – FSW.

17

Mechanical properties of AW-5083 alloy joints welded by hybrid method : FSW and MIG

Dudzik Krzysztof

Journal of KONES

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2019

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Vol. 26, No. 4

47--52

EN

The article presents the research results on the mechanical properties of aluminum alloy AW-5083 and its joints welded by hybrid method – traditional MIG and FSW. AW-5083 alloy is the most currently used in shipbuilding industry. Friction Stir Welding (FSW) – a new technology can be successfully used for butt-welding of different types of aluminum alloy sheets. FSW method can be an alternative to traditional arc welding methods i.e. MIG or TIG. Hybrid welding (FSW with MIG or TIG) could be used in cases when joining only by FSW is not possible. Welding parameters used for the connection of the sheets were presented. Metallographic analysis showed the correct construction of structural bonded joints. The research was carried out using a static tensile test in accordance with the requirements of the Standard PN-EN ISO 4136:2013-05. Flat samples cut perpendicular to the direction of rolling were used. The research was conducted at the temperature of +20ºC. The test shows that the mechanical properties of joints made by hybrid method compered to native material were lower. The tensile strength of joint was lower by 20% then native material 5083 while its yield stress was lower only about 6%. The biggest change was observed in case of plastic properties. Elongation of joint was over 50% lower compared to native material. Despite the decrease of mechanical properties, they meets the requirements of classification societies, so the conclusion is that hybrid method (FSW and MIG) of joining AW-5083 can be applied in shipbuilding industry.

18

Analysis of wear of tools made of 1.2344 steel and MP159 alloy in the process of friction stir welding (FSW) of 7075 T6 aluminium alloy sheet metal

Więckowski Wojciech, Burek Rafał, Lacki Piotr, Łogin Waldemar

Eksploatacja i Niezawodność

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2019

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Vol. 21, no. 1

54--59

EN

The study presents an analysis of wear of tools made of 1.2344 steel and MP159 alloy for the process of obtaining an overlap joint in 1.0 mm and 0.8 mm sheet metal made of 7075 T6 aluminum alloy using friction stir welding (FSW) technology. Tool geometry was designed at the Czestochowa University of Technology. Evaluation of tool wear was conducted based on the measurements of geometry of working area of tools by means of a multisensory meter system and based on the assessment of the working area by means of a stereoscope after individual stages of wear tests. Furthermore, based on the results of a static tensile strength test and metallographic examinations of the specimens sampled from the joints obtained during tool wear tests, the effect of the degree of tool wear on joint quality was also evaluated. Analysis of the results revealed that both the tool made of 1.2344 steel and that made of MP159 alloy were substantially worn, increasing the risk of further use of the tools for the joint material (7075-T6) after obtaining the joint with length of 200m, which suggests their low durability. Furthermore, modification of tool geometry caused by wear led to insignificant improvements in joint strength. Therefore, the results of wear measurement set directions for further modification of tool geometry, also due to the fact that despite a substantial wear, the tools continued to yield high-quality joints without defects. As demonstrated in the study, the type of tool material does not only impact on tool life but also, as it was the case in their geometry, has a significant effect on the quality of obtained joints. Although the tool made of MP159 alloy was worn more than the tool made of 1.2344 steel, it allowed for obtaining the joints with substantially better strength parameters.

PL

W pracy przedstawiono analizę procesu zużycia narzędzi wykonanych ze stali 1.2344 oraz stopu MP159 w procesie wykonywania złączy zakładkowych z blach ze stopu aluminium 7075 T6 o grubości 1,0mm i 0,8mm technologią zgrzewania tarciowego z przemieszaniem materiału (FSW). Geometrię narzędzi użytych do badań opracowano na Politechnice Częstochowskiej. Ocenę zużycia narzędzi przeprowadzono w oparciu o pomiary geometrii części roboczej narzędzi na maszynie multisensorycznej oraz na podstawie oględzin powierzchni roboczej przy użyciu stereoskopu po kolejnych etapach badań zużycia narzędzia. Dodatkowo, w oparciu o wyniki statycznej próby rozciągania oraz badania metalograficzne próbek pobranych ze złączy wykonywanych w trakcie badań zużycia narzędzi, przeprowadzono ocenę wpływu stopnia zużycia narzędzi na jakość wykonanych złączy. Na podstawie analizy wyników można stwierdzić, że zarówno narzędzie wykonane ze stali 1.2344 oraz ze stopu MP159 ulegają intensywnemu, zagrażającemu ich dalszej eksploatacji zużyciu, we współpracy z materiałem zgrzeiny (7075-T6) już po wykonaniu złącza o długości 200m, co świadczy o ich niskiej trwałości. Przy czym zmiany geometrii narzędzia spowodowane zużyciem pozwoliły na nieznaczną poprawę wytrzymałości złączy. Uzyskane wyniki pomiarów zużycia wyznaczają zatem kierunek w procesie dalszej modyfikacji geometrii badanych narzędzi, również z uwagi na fakt, iż pomimo znaczącego zużycia badanych narzędzi, pozwalały one w dalszym ciągu uzyskać dobre jakościowo złącza pozbawione wad. Jak wykazały badania, rodzaj materiału narzędzia wpływa nie tylko na trwałość narzędzi ale również, jak ma to miejsce w przypadku ich geometrii, ma on istotny wpływ na jakość uzyskanych połączeń. Pomimo tego, że narzędzie wykonane ze stopu MP159 uległo większemu zużyciu w porównaniu z narzędziem ze stali 1.2344, to pozwoliło ono uzyskać złącza o znacznie lepszych parametrach wytrzymałościowych.

19

The application of the bobbin tool in the friction stir welding of aluminium sheets

Węglowska Aleksandra

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2019

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Vol. 63, No. 5

23--32

EN

The article presents the effect of the technological parameters of the friction stir welding of 2 mm thick aluminium sheets made of aluminium alloy EN AW 6082 performed using of the bobbin tool. The tests included static tensile tests, hardness tests and macroscopic metallographic tests. The tests revealed that properly selected welding parameters enabled the obtainment of joints characterised by material continuity, compact structure and the lack of welding imperfections in the welding area. The application of the bobbin tool made it possible to obtain joints of aluminium sheets characterised by high strength, i.e. amounting to 61% of the base material strength.

PL

Przedstawiono wpływ parametrów technologicznych zgrzewania metodą FSW blach o grubości 2 mm ze stopu aluminium EN AW 6082 przy użyciu narzędzia szpulowego „bobbin tool”. Badania obejmowały statyczną próbę rozciągania, pomiary twardości oraz badania metalograficzne makroskopowe. Wykazano, że przy prawidłowo dobranych parametrach zgrzewania złącza charakteryzują się ciągłością materiałową, zwartą strukturą i brakiem niezgodności spawalniczych w obszarze zgrzewania. Przy zastosowaniu narzędzia szpulowego możliwe jest uzyskanie złączy cienkich blach aluminiowych, o wysokiej wytrzymałości wynoszącej 61% wytrzymałości materiału rodzimego.

20

The Numerical Simulation of Aviation Structure Joined by FSW

Lacki P., Adamus K., Winowiecka J.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

387--392

EN

This work presents a numerical simulation of aviation structure joined by friction stir welding, FSW, process. The numerical simulation of aviation structure joined by FSW was created. The simulation uses thermomechanical coupled formulation. The model required creation of finite elements representing sheets, stiffeners and welds, definition of material models and boundary conditions. The thermal model took into account heat conduction and convection assigned to appropriate elements of the structure. Time functions were applied to the description of a heat source movement. The numerical model included the stage of welding and the stage of releasing clamps. The output of the simulation are residual stresses and deformations occurring in the panel. Parameters of the global model (the panel model) were selected based on the local model (the single joint model), the experimental verification of the local model using the single joint and the geometry of the panel joints.