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1

Deep Convolutional Neural Network Algorithm for Prediction of the Mechanical Properties of FSW Copper Welds from its Microstructure

Mishra Akshansh, Suman Asmita

Welding Technology Review

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2023

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R. 95

25--31

EN

Convolutional Neural Network (CNN) is a special type of Artificial Neural Network which takes input in the form of an image. Like Artificial Neural Network they consist of weights that are estimated during training, neurons (activation functions), and an objective (loss function). CNN is finding various applications in image recognition, semantic segmentation, object detection, and localization. The present work deals with the prediction of the welding efficiency of the Friction Stir Welded joints on the basis of microstructure images by carrying out training on 3000 microstructure images and further testing on 300 microstructure images. The loss function decreased for both training and testing set decreased with the increasing number of epochs. The obtained results showed an accuracy of 80 % on the validation dataset.

2

Numerical analysis of stress and temperature in the friction stir welding (FSW) process of steel

Szczecina Michał

Structure and Environment

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2023

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Vol. 15, no. 4

196--207

EN

Friction stir welding (FSW) is a modern technology for joining various metals, which has already undergone many laboratory tests, but still requires the development of numerical models. Author of the paper decided to summarize the current state of scientific knowledge regarding the modelling of the FSW process using the finite element method (FEM) and showed the main directions of development of numerical research on this process. Very advanced models are a combination of solid mechanics and fluid dynamics, but they often require expanding the computing environment with its own subroutines, as well as calibration and validation of some material parameter and constants occurring e.g. in the heat generation and heat flow laws. The Author of the paper proposed his own, simplified model, based on the computational solid mechanics and Lagrangian formulation. The model turned out to be an effective tool to reproduce stress and temperature fields during the FSW process.

PL

Zgrzewanie tarciowe z przemieszaniem (FSW) jest nowoczesną technologią łączenia różnych metali, posiadającą wiele zalet w porównaniu z tradycyjnym spawaniem. Zgrzewanie tarciowe zostało do tej pory poddane licznym badaniom laboratoryjnym, natomiast wymaga ciągłego rozwoju modeli numerycznych do symulacji tego procesu metodą elementów skończonych (MES). Autor artykułu postanowił dokonać podsumowania aktualnego stanu wiedzy dotyczącej modelowania zgrzewania tarciowego przy użyciu MES oraz wskazać główne kierunki rozwoju symulacji numerycznych tego procesu. Zaawansowane modele numeryczne zgrzewania tarciowego są kombinacją mechaniki ciała stałego z dynamiką płynów, a więc często wymagają rozbudowania środowiska obliczeniowego za pomocą własnych podprogramów, jak również kalibracji i walidacji wielu parametrów i stałych wymaganych do zdefiniowania np. prawa wytwarzania ciepła i prawa przepływu strumienia ciepła. Autor zaproponował swój własny uproszczony model bazujący na mechanice ciała stałego i opisie Lagrange’a. Model okazał się efektywnym narzędziem do odtworzenia naprężeń i pola temperatury w procesie zgrzewania tarciowego z przemieszaniem.

3

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.

4

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.

5

Influence of tool pin profile and welding parameters on microstructure and mechanical properties of dissimilar friction stir welded AA2024 to AA7075 alloys

Mohammed H. B., Naemah I. M., Jomah A. J. S., Alrubaiy A. A. A. G.

Archives of Materials Science and Engineering

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2023

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Vol. 124, nr 1

14--24

EN

Purpose: The paper aims to produce aluminium welds in the solid state with good specifications and the least amount of welding defects by using the friction stir welding method (FSW) and different tool pin profiles and welding parameters. The research investigated the mechanical characteristics and microstructure of a friction stir welded dissimilar aluminium alloy (2024-T3 to 7075-0) through thickness produced by varying welding settings and three different FSW tool pin shapes. Design/methodology/approach: The objective is to obtain the welds with the least amount of welding defects in the solid state by using the friction stir welding method (FSW), designing the tool pin profiles, and changing the rotation speeds. Findings: According to tensile strength and micro-hardness tests, tool rotation of 2000 rpm and square pin profile were the best compared to other working parameters. The greatest hardness and highest tensile strength of FSWed dissimilar aluminium joints have been 144 HV and 215 MPa, respectively, when using the square pin profile at a tool rotation speed of 2000 rpm. The hardness and tensile strength of FSWed dissimilar aluminium alloy joints increase with the tool rotation speed. Microstructural observations of the FSWed dissimilar aluminium joints using a square pin profile at the tool rotation speed of 2000 rpm exhibited the weld zone's high weld quality. Additionally, there were no defects in the weld zone. The fracture surface of the FSWed joint indicated a ductile fracture type. Research limitations/implications: With many regions on either side of the weld with varied compositions, microstructures, and characteristics, the resulting welds of dissimilar alloys might result in unsatisfactory weld joints. Practical implications: The weld zone's exceptional weld quality was demonstrated by microstructural investigations of the FSWed dissimilar aluminium connections utilising a square pin profile at a tool rotation speed of 2000 rpm and feed rate of 20 mm per minute. Application in aerospace, shipbuilding and marine, railway, construction, electrical industries, and land transportation. Originality/value: The original value of the paper is the production of welds from dissimilar aluminium alloy (2024-T3 to 7075-0) with the least amount of welding defects by changing the tool pin profiles and tool rotation speeds using the friction stir welding method.

6

Computed Tomography and Scanning Electron Microscopy Analysis of a Friction Stir Welded Al-Cu Joint

Depczyński Wojciech P., Bańkowski Damian, Młynarczyk Piotr S.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 4

65--71

EN

The study aimed touse3D computed tomography (CT) to analyse a joint between two dissimilar materials produced by friction stir welding (FSW). As the materials joined, i.e., aluminum and copper, differ in properties (e.g., density and melting point), the weld is predicted to have an inhomogeneous microstructure. The investigations involved applying microfocus computed tomography (micro-CT) to visualize and analyze the volumetric structure of the joint. Volume rendering is extremely useful because, unlike computer modelling, which requires many simplifications, it helps create highly accurate representations of objects. Image segmentation into regions was performed through global gray-scale thresholding. The analysis also included elemental mapping of the weld cross-sections using scanning electron microscopy (SEM) and examination of its surface morphology by means of optical microscopy (OP). The joint finds its use in developing elements used in the chemical, energetics and aerospace industries, due to the excellent possibilities of combining many different properties, and above all, reducing the weight of the structure.

7

Enhancing the properties of friction stir welded joints of L-PBF printed AlSi10Mg alloy via multi-variable optimization

Minhas Navdeep, Sharma Varun, Bhadauria Shailendra Singh

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e60, 2023

EN

The feasibility study to join the laser powder bed fused AlSi10Mg alloy sheets using different friction stir welding parameters was investigated in the present work. Fifteen butt-welded joints using varied parametric combinations were developed based on the design of the experiment's approach. An empirical model between the process parameters and tensile strength was developed and used to understand the mechanical behavior of the welded joints w.r.t. the FSW parameters, followed by the attainment of optimized welding conditions using response surface methodology. The results inferred that the weldability was most significantly influenced by the tool rotational speed, followed by the tool tilt angle and tool traverse speed. The microstructure and mechanical properties of the optimized welded joint were compared with the as-built alloy and the welded joint yielding minimum tensile strength. The electron back scattered diffraction analysis revealed the reduction of average grain size of the stir zone of the joints by 21% for the optimized weld, as compared to the as-built alloy. The welded zones of the joints showed a reduction in hardness by 40-50% and formed the stir zone as the weakest link. The parametric combinations of the optimized weld improved the joint efficiency by ≈ 20% compared to the other weld, followed by an improvement in ductility, which was further characterized using scanning electron microscopy.

8

Mechanical and corrosion properties of Friction Stir Welded and Tungsten Inert Gas welded phosphor bronze

Gopi S., Mohan Dhanesh G., Natarajan Elango

Advances in Materials Science

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2023

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Vol. 23, nr 4(78)

83--98

EN

This study investigated the mechanical and corrosion properties of Friction Stir Welded (FSW) and Tungsten Inert Gas (TIG) welded phosphor bronze (CuSn4) joints. Corrosion tests were conducted on the welded joints, and the percentage of weight loss due to corrosion was measured at different time intervals. Results revealed that the percentage of weight loss due to corrosion of the TIG joint increased with time, whereas the percentage of weight loss due to corrosion of the FSW welded joint remained constant. This could be attributed to recrystallisation that happened in the solid-state welding, which reduced corrosion in the FSW welded joint. In addition, tensile tests were conducted to evaluate the strength of the joints. FSW with a spindle speed of 1300 rpm, weld speed of 0.06mm/sec, plunge depth of 0.25mm, pin profile of pentagon, and flat shoulder profile was found to produce good results. TIG welding with a welding speed of 1.75mm/sec, a gas flow rate of 7.5 cm3/min and an amperage of 120A also produced good results. The tensile strength of FSW was found to be approximately 1.6 times higher than that of TIG welding.

9

A new tooling approach for friction stir welding of thin sheet AA2024-T3 - optimization of welding parameters

Myśliwiec Piotr

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2022

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z. 94

37--50

EN

In this study a new ceramics tools with different groove distributions were designed and manufactured in order to enrich technological storage of joining thinwall structures and obtain sound joint with high quality of Alclad AA2024-T3 alloy of 0.5 mm in thickness. Four types of tools were tested, without grooves, with 1, 2 and 6 grooves. The tools are made of two materials. The straight shank is made from tungsten carbide and tool body made from ceramics strengthened with whiskers. The influence of technological parameters on the strength of FSW joints was tested by the Response Surface Methodology (RSM) and Analysis of Variance (ANOVA) method. The least durable weld is produced by a tool without grooves. The single and double flute tool produces a good quality weld over a wide range of tool speeds. It has been shown that the grooves on the tool shoulder significantly affect the quality of the obtained FSW joint.

PL

W pracy zaprojektowano i wykonano nowe narzędzia ceramiczne o różnym rozkładzie rowków w celu wzbogacenia technologii łączenia konstrukcji cienkościennych i uzyskania wysokiej jakości połączenia blach ze stopu aluminium AA2024-T3 Alclad o grubości 0,5 mm. Przetestowano cztery typy narzędzi, bez rowków, z 1, 2 i 6 rowkami. Narzędzia wykonano z dwóch materiałów. Część chwytową wykonano z węglika wolframu, a korpus narzędzia z ceramiki wzmocnionej whiskerami. Wpływ parametrów technologicznych na wytrzymałość złączy FSW badano metodami analizy powierzchni odpowiedzi (RSM) oraz analizy wariancji (ANOVA). Najmniej trwałą spoinę wytworzyło narzędzie bez rowków. Narzędzie z pojedynczym i podwójnym rowkiem zapewniło dobrej jakości spoinę w szerokim zakresie prędkości obrotowych narzędzia. Wykazano, że rowki na kołnierzu narzędzia istotnie wpływają na jakość uzyskanego połączenia FSW.

10

Zastosowanie zgrzewania tarciowego z przemieszaniem (FSW) do wykonywania połączeń doczołowych wysokowytrzymałych stopów aluminium stosowanych w przemyśle zbrojeniowym

Kosturek Robert

Stal, Metale & Nowe Technologie

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2022

|

nr 9-10

38--41

PL

Otrzymywanie wysokiej jakości połączeń spójnościowych umacnianych wydzieleniowo stopów aluminium stanowi jedną z decydujących batalii na froncie rozwoju współczesnej techniki, będąc istotnym motorem postępu przemysłu motoryzacyjnego, lotniczego i zbrojeniowego.

EN

This paper presents selected results of research concerning AA2519-T62 and AA7075-T651 butt joints produced with the FSW technique, including macroscopic observations, microhardness distributions and tensile tests. The applied welding technique enabled obtaining high-quality welds of the 87% and 77% joint efficiencies for AA2519-T62 and AA7075- -T651 respectively.

11

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

|

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.

12

Prediction of filler added friction stir welding parameters for improving corrosion resistance of dissimilar aluminium alloys 5052 and 6082 joints

Sasikumar A., Gopi S., Mohan Dhanesh G.

Advances in Materials Science

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2022

|

Vol. 22, nr 3(73)

79--95

EN

The aluminium alloys 5052 and 6082 are extensively used in manufacturing lighter structural members, having improved strength and resistance to corrosion. Magnesium (Mg) and Chromium (Cr) powder were the filler materials selected for enhanced corrosion protection properties in this investigation. Friction stir welding (FSW) process parameters viz., spindle speed, welding speed, shoulder penetration, the centre distance between the holes and filler ratio are used to forecast the minimum corrosion rate from different weld regions of AA5052-AA6082 dissimilar joints. Response surface methodology based on a central composite design was used to evolve the mathematical models and estimate dissimilar FSW joints’ corrosion rates. Response optimization shows that the minimum corrosion rate was achieved by the welding parameters of spindle speed 1000 rev/min, welding speed 125 mm/min, holes spacing of 2 mm and filler ratio 95% of Mg and 5% of Cr.

13

Mathematical model for friction stir lap welded AA5052 and SS304 joints and process parameters optimization for high joint strength

Chitturi Veerendra, Pedapati Srinivasa Rao, Awang Mokhtar

Advances in Materials Science

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2022

|

Vol. 22, nr 1(71)

5--22

EN

Due to the numerous challenges faced during the dissimilar welding, choosing the right process parameters and their optimization yields better results. In this context, the current investigation is focused on the optimization of process parameters. Taguchi's L9 orthogonal array was selected to carry out the experimental investigations. The welded samples were tested for shear strength, and the results were analysed using Taguchi's S/N ratio analysis with "larger the better" criteria. Log-linear regression analysis was applied to formulate an empirical correlation between the process parameters and shear strength. According to S/N ratio analysis, the tool rotational speed of 800 rpm, welding speed of 20 mm/min and a penetration depth of 4.1 mm are the optimized parameters that achieve high joint strength. The achieved joint strength was 3.46 kN that is 70% of the base aluminium metal. It was noticed from the Analysis of variance of the regression model that penetration depth and tool rotational speed are the significant contributors with p-values less than 0.5. Confirmation tests show that the error between the predicted and calculated shear strength is 2.06% which is considered acceptable. R2 and adjusted R2 values of the model with a standard error of 0.076 show that the developed model is statistically significant.

14

Friction Stir Welding/Processing of High Entropy Alloys (HEAs)

Mishra Akshansh

Welding Technology Review

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2021

|

R. 93, nr 1

27--33

EN

The composition of High Entropy Alloys is quite different from the existing classical engineering alloys because in near equiatomic ratios they contain multiple principal alloying elements. Design and development of high entropy alloys is very important to overcome the shortcomings of conventionally used alloys in applications where operating conditions of temperature and loading are extreme. High entropy alloys generally find applications in compressor blades of an aerospace engine, energy, and transportation industries due to its low density and high strength. In order to enhance the application of high entropy alloys, the proper selection of a feasible welding process is very important. It has been observed that when high entropy alloys are subjected to the welding process other than the Friction Stir Welding process then it will result in reduced overall strength and lower hardness in the fusion zone and heat-affected zone. In this recent paper, the application of Friction Stir Welding for joining the high entropy alloys and also using Friction Stir Processing for improving the mechanical and microstructure properties of high entropy alloys are discussed.

PL

Projektowanie i opracowywanie stopów o wysokiej entropii jest bardzo ważne, aby przezwyciężyć niedociągnięcia konwencjonalnie stosowanych stopów w zastosowaniach, w których warunki pracy, takie jak temperatura i obciążenie, są ekstremalne. Stopy o wysokiej entropii zwykle znajdują zastosowanie w łopatkach sprężarek silników lotniczych, energetyce i transporcie ze względu na ich niską gęstość i wysoką wytrzymałość. Aby usprawnić stosowanie stopów o wysokiej entropii, bardzo ważny jest właściwy dobór możliwego do wykonania procesu spawania. Zaobserwowano, że gdy stopy o wysokiej entropii zostaną poddane procesowi spawania innemu niż proces zgrzewania tarciowego z mieszaniem, to spowoduje to zmniejszoną ogólną wytrzymałość i niższą twardość w strefie topienia i strefie wpływu ciepła. W artykule omówiono zastosowanie zgrzewania tarciowego z przemieszaniem do łączenia stopów o wysokiej entropii, a także zastosowanie tarciowej modyfikacji z przemieszaniem do poprawy właściwości mechanicznych i mikrostrukturalnych tych stopów.

15

Forecasting process parameters on weld nugget hardness of filler added friction stir welded dissimilar aluminium alloys 5052 and 6082 joints

Sasikumar A., Gopi S., Mohan Dhanesh G.

Journal of Mechanical and Energy Engineering

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2021

|

Vol. 5, No 2

103--112

EN

This article deals with the optimization of friction stir welding process parameters with filler ratios on dissimilar Aluminium alloy groups. For this purpose, 6 series Aluminium alloy 6082 and 5 series Aluminium alloy 5052 were taken. Microhardness property was conducted under various rotational speeds, welding speed, plunge depth, Center distance between the holes and filler mixing ratio. The Central Composite Design (CCD), the most commonly used Response Surface Methodology (RSM), is considered to develop the prediction equation. A validation analysis is carried out, and the results were compared with the relative impact of input parameters on weld nugget microhardness. It is observed that the increase in welding speed with plunge depth and filler ratio result in the increase of weld nugget microhardness up to a maximum value. The maximum weld nugget hardness of fabricated joint was obtained with the welding process parameters combination of 1000 rpm rotational speed, 125 mm/min welding speed, 0.15 mm plunge depth, 2 mm centre distance between the holes, and filler ratio of 95% Mg and 5% Cr.

16

Design of Functionally Graded Composites through Friction Stir Processing

Sai B. V. Hima Sekhar

Journal of Mechanical and Energy Engineering

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2021

|

Vol. 5, No 2

95--101

EN

An Investigation was conducted to produce Aluminium based Functionally graded material (FGM) composites by Friction stir processing (FSP). A reinforcement strategy featuring the use of Alumina and TiC reinforcements was investigated, where holes were drilled in an Aluminium plate, filled with reinforcements and stirred using FSP. A mathematical model was formulated for the positioning of holes in such a manner that the composition of the reinforcements varies from maximum to minimum over a given length. Samples were subjected to various numbers of FSP passes from one to three with a 100% overlap and its influence on particle distribution and homogeneity was studied using Scanning electron microscopy (SEM) at cross sections parallel to the tool traverse direction. A progressive gradient in hardness values was observed for the surface composites at all the passes.

17

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

|

2021

|

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.

18

Internal flow behaviour and microstructural evolution of the bobbin-FSW welds: thermomechanical comparison between 1xxx and 3xxx aluminium grades

Tamadon Abbas, Pons Dirk J., Sued Kamil, Clucas Don

Advances in Materials Science

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2021

|

Vol. 21, nr 2(68)

40--64

EN

The influences of processing parameters and tool feature on the microstructure of AA1100 and AA3003 aluminium alloys were investigated using bobbin friction stir welding (BFSW). The research includes flow visualization and microstructural evolution of the weld texture using the metallographic measurement method. Results indicated that the operational parameters of the welding (e.g. feed rate, rotating speed) and the geometry of the tool can directly affect the flow patterns of the weld structure. The microscopic details revealed by the optical and electron microscope imply the dynamic recrystallization including grain refinement and precipitation mechanisms within the stirring zone of the weld region. The microscopic observations for the weld samples show a better performance of the fully-featured tool (tri-flat threaded pin and scrolled shoulders) compared to the simple tool without inscribed surface features. The fully-featured tool resulted in a more uniform thermomechanical plastic deformation within the weld structure along with the precipitation hardening and the homogeneity of the microstructure.

19

Induction assisted hybrid friction stir welding of dissimilar materials AA5052 aluminium alloy and X12Cr13 stainless steel

Mohan Dhanesh G., Tomków Jacek, Gopi S.

Advances in Materials Science

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2021

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Vol. 21, nr 3(69)

17--30

EN

This research aimed to study the induction in-situ heated hybrid friction stir welding (IAFSW) method to join AA5052 aluminium alloy with X12Cr13 stainless steel (SS) to enhance joint strength. The potency of this method on the mechanical properties and microstructural characterizations were also investigated. The results show that the transverse tensile strength gained was 94% of the AA5052 base metal that is 229.5 MPa. This superior strength was achieved due to the annealing that happened to the AA 5052 region and elevated plastic flow in the weld zone by the in-situ induction heating, which resulted in the elongation of the weld region. The microstructure characterization indicates that a refined grain structure was gained in the nugget zone without defects.

20

Assessment of corrosive behaviour and microstructure characterization of hybrid friction stir welded martensitic stainless steel

Mohan Dhanesh G., Gopi S., Tomków Jacek, Memon Shabbir

Advances in Materials Science

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2021

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Vol. 21, nr 4(70)

67--78

EN

This study examined the effect of induction heating on the microstructure and corrosion characteristics of hybrid friction stir welded AISI 410 stainless steel. Five joints have been produced with different friction stir welding parameters like welding speed, spindle speed, plunge depth, and induction power. Their microstructures were evaluated using a scanning electron microscope, and chemical composition was examined using energy-dispersive X-ray spectroscopy (EDX). The rate of corrosion was found out via the weight loss method in a 1 M HCL solution. The hybrid friction stir welding method used for this work is induction assisted friction stir welding; the results show that this method could produce sound AISI 410 stainless steel Joints. The experiment results show that the joint made at a spindle speed of 1150 rpm, welding speed 40 mm/min, plunge depth 0.5 mm, and in-situ heat by induction 480°C show a better corrosion resistance property with a fine grain structure.