scholarly journals A New Approach in Surface Modification and Surface Hardening of Aluminum Alloys Using Friction Stir Process: Cu-Reinforced AA5083

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1278 ◽  
Author(s):  
Ioannis G. Papantoniou ◽  
Angelos P. Markopoulos ◽  
Dimitrios E. Manolakos
Keyword(s):  
Surface Modification ◽  
Aluminum Alloys ◽  
Surface Hardening ◽  
Thin Sheet ◽  
Pure Copper ◽  
High Heat ◽  
Stir Zone ◽  
New Approach ◽  
Friction Stir ◽  
Almost All

In the current study, a new approach for surface modification and surface hardening of aluminum alloys is developed. The method is based on the logic of in-situ reinforcing FSP strategies. The novelty of the proposed process is the application of a bulk reinforcing metallic material instead of metallic powders. The FSP was carried out on aluminum alloy AA5083—thick plates. A thin sheet of pure copper (cross-section 4 × 0.8 mm2) was placed in a machined groove on the upper surface of the aluminum plate, and both materials were FSPed together. Samples with one, two and three FSP passes were manufactured respectively. Results indicate that the copper thin sheet was successfully integrated in the AA5083 stir zone. By increasing the FSP passes, almost all copper was integrated in the stir zone, mainly in the form of coper-based micron-sized intermetallic particles, and secondly, by copper diffusion in the AA5083 matrix. Due to the presence of complex intermetallic compounds created by the high heat input and intense plastic deformation, the hardness inside the stir-zone was found highly increased from 77 to 138 HV.

Stir zone material flow patterns during friction stir welding of heavy gauge AA5056 workpieces and stability of its mechanical properties

2021 ◽  
Vol 23 (4) ◽  
pp. 140-154
Author(s):  
Tatiana Kalashnikova ◽  
◽  
Vladimir Beloborodov ◽  
Kseniya Osipovich ◽  
Andrey Vorontsov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Elevated Temperatures ◽  
Thin Sheet ◽  
Stir Zone ◽  
Clear Correlation ◽  
Material Structure ◽  
Friction Stir ◽  
Significant Difference

Introduction. Friction stir welding and processing are almost identical processes of severe plastic deformation at elevated temperatures. These technologies differ mainly in the purpose of its use: the formation of a hardened surface layer or producing a welded joint. However, it is known that both during welding and during processing of heavy gauge workpieces temperature gradients occur. As a result, the conditions of adhesive interaction, material plastic flow, and the formation of the stir zone change as compared to thin-sheet workpieces with fundamentally different heat dissipation rates. In this connection, the purpose of the work is to determine the regularities of the structure formation and stability of the mechanical properties in different directions in the material of 35-mm-thick aluminum-magnesium alloy samples produced by friction stir welding/processing. Research Methodology. The technique and modes of friction stir welding and processing of AA5056 alloy workpieces with a thickness of 35 mm are described. Data on the equipment used for mechanical tests and structural research are given. Results and discussion. The data obtained show the excess mechanical properties of the processing zone material over the base metal ones in all studied directions. Material structure heterogeneities after friction stir welding/processing of heavy gauge workpieces have no determining effect on the stir zone properties. At the same time, there is no clear correlation between the tensile strength values and the load application direction, nor is there any significant difference in mechanical properties depending on the location of the samples inside the stir zone. The average ultimate tensile strength values in the vertical, transverse, and longitudinal directions are 302, 295 and 303 MPa, respectively, with the yield strength values of 155, 153 and 152 MPa, and the relative elongation of 27.2, 27.5, 28.7 %.

scholarly journals Microstructure and Mechanical Properties of Friction Stir Welded Joints Between Commercially Pure Copper and Al 6351 Alloy

2017 ◽  
Vol 62 (3) ◽  
pp. 1819-1825
Author(s):  
V.C. Sinha ◽  
S. Kundu ◽  
S. Chatterjee
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Rotational Speed ◽  
Pure Copper ◽  
Stir Zone ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Commercially Pure ◽  
Microstructure And Mechanical Properties ◽  
Commercially Pure Copper

AbstractIn the present study, the effect of tool rotational speed on microstructure and mechanical properties of friction stir welded joints between commercially pure copper and 6351 Al alloy was carried out in the range of tool rotational speeds of 300-900 rpm in steps of 150 rpm at 30 mm/minutes travel speed. Up to 450 rpm, the interface of the joints is free from intermetallics and Al4Cu9intermetallic has been observed at the stir zone. However, Al4Cu9intermetallic was observed both at the interface and the stir zone at 600 rpm. At 750 and 900 rpm tool rotational speed, the layers of AlCu, Al2Cu3and Al4Cu9intermetallics were observed at the interface and only Al4Cu9intermetallics has been observed in the stir zone. The maximum ultimate tensile strength of ~207 MPa and yield strength of ~168 MPa along with ~6.2% elongation at fracture of the joint have been obtained when processed at 450 rpm tool rotational speed.

Improvement in Mechanical and Metallurgical Properties of Friction Stir Welded 6061-T6 Aluminum Alloys through Cryogenic Treatment

2019 ◽  
Vol 969 ◽  
pp. 490-495
Author(s):  
K. Tejonadha Babu ◽  
S. Muthukumaran ◽  
C.H. Bharat Kumar ◽  
C. Sathiya Narayanan
Keyword(s):  
Aluminum Alloys ◽  
Welded Joints ◽  
Cryogenic Treatment ◽  
Base Material ◽  
Cryogenic Cooling ◽  
Stir Zone ◽  
Welding Parameters ◽  
Cooling Rates ◽  
Friction Stir ◽  
Metallurgical Properties

An investigation has been made to improve the properties of the friction stir welded (FSW) 6061-T6 aluminum alloys. A cryogenic thermal treatment is developed for the joints during welding and its effects on mechanical and metallurgical properties, and precipitates are evaluated at various welding parameters. The friction stir welded joints with cryogenic treatment attained the better properties than the without cryogenic treatment. The improvement of properties was attributed to the refinement of grain size and to the introduction of a reduction in the softening region of the welded joints. Under cryogenic cooling rates, joints were experienced to the low temperature environments and faster cooling rates, which are contributed to enhance the hardness of the stir zone and heat affected zone regions and the formation of fine grain structure in the stir zone. The results indicated that the formation of finer grains of less than 5 µm in the stir zone, which is smaller than the joints of without cryogenic treatment. Subsequently, mechanical properties drastically improved and the joints achieved a maximum joint efficiency of 74% of the base material

Statistical Investigations on Friction Stir Welded Aluminum Tailored Blanks for a Robust Process Window

2005 ◽  
Vol 6-8 ◽  
pp. 599-606 ◽  
Author(s):  
Arthur Giera ◽  
Marion Merklein ◽  
Manfred Geiger
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Process Parameters ◽  
Thin Sheet ◽  
Cost Effective ◽  
Process Window ◽  
Tool Geometry ◽  
Main Process ◽  
Friction Stir ◽  
Welding Processes

The multifarious applications of aluminum alloys in different industrial domains are based on the mechanical properties as well as the light weight characteristics, which allow energy saving for the products in use. Nevertheless aluminum alloys are considered to be difficult to weld by conventional welding processes. This paper deals with cost-effective friction stir welding of thin sheet aluminum alloys in thicknesses of about 1 mm to widen the possible range of applications. Based on former studies results will be shown how an optimized tool geometry increases the mechanical properties of friction stir welded parts. The characteristics of these friction stir welded thin sheets will be analysed in a statistical evaluation in order to detect the interactions and dependencies of the process parameters. By highlighting the main process parameters and their significances a process window for friction stir welded blanks of AA5182 and AA6016 is presented.

scholarly journals A Study of the Metallurgical and Mechanical Properties of Friction-Stir-Processed Cu

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 656
Author(s):  
Michael Regev ◽  
Stefano Spigarelli
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Parent Material ◽  
Stir Zone ◽  
New Approach ◽  
Friction Stir ◽  
Fine Grain ◽  
Plastic Deformation Process ◽  
Uniform Cross Section ◽  
Pure Cu

Friction stir processing (FSP), a severe plastic deformation process, was applied on pure Cu to obtain a stir zone with a very fine grain size. Yet, when FSP is used, the stir zone is as wide as the diameter of the shoulder at the upper surface of the weld and markedly narrower near its opposite surface. This property, as well as the differences between the advancing side and the retreating side, makes it impossible to obtain a uniform cross-section as far as the microstructure and mechanical properties are concerned. For these reasons, a new approach is proposed in which the material was processed on both sides, thus yielding a wider, rectangular and more homogenous stir zone from which all the specimens were machined out. Processing the material from both sides eliminated any microstructural difference between the upper and the lower side, at least within the gauge length’s cross-section of the creep specimens. Although grain refinement was detected, the mechanical properties of the friction-stir-processed (FSP’ed) material are inferior relative to those of the parent material. The TEM study reported in the current paper revealed the existence of nanosized grains in the FSP’ed material due to dynamic recrystallization (DRX) occurring during the processing stage. Because both X-ray inspection and fractography showed that the FSP’ed material was free of defects, the material may not comply with the Hall–Petch relation due to lower dislocation density caused by XRD occurring during FSP. The inverse Hall–Petch effect may also be considered as an assistive mechanism in mechanical property deterioration.

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