Although the intermetallic compounds exist in all specimens, the main cause of the high microhardness in the specimen is due to its smaller grain size, compared to rest of the specimens. They concluded that the increase of the heat input promotes the formation of the IMCs.
Kush et al. They described that higher heat input condition such as higher rotational speed [ 5 ], lower welding speed [ 14 ], larger shoulder diameter [ 16 ] and higher tilt angle [ 35 ] will result in higher amounts of IMCs in SZ, which subsequently increase the hardness. So, for specimen, the amount of heat generation was greater than that of the other specimens, while the microhardness was very close to that of the specimen, owing to the formation of more IMCs.
In fact, for specimen with coursing grain size, the formation of IMCs is the main factor for its higher microhardness and weakening tensile properties, which will be discussed later. Meanwhile, the microhardness of the HAZ of specimen was lower than that of the other specimens especially aluminum , due to a rise in its grain size. Basically, the mechanical properties of FSW between aluminum and copper mainly depend on the microstructure and intermetallic compounds. As a result, the joint efficiency is even lower than the low-strength materials. Figure 12 shows the tensile properties such as UTS, percentage of elongation, yield stress YS and failure energy.
Generally, mixing and flow of the material between aluminum and copper [ 7 ], finer grain in SZ [ 5 ], the amount of intermetallic compounds [ 9 , 10 , 31 ] and distribution of copper pieces [ 4 , 13 , 18 , 32 ] may be the most important factors affecting the tensile properties of dissimilar joints between aluminum and copper.
By further increase in heat generation for the , and specimens, the UTS was reduced and reached , and MPa and the elongation was decreased and reached 4. As mentioned above, by rising heat generation, UTS increases and reaches MPa, for specimen. Afterward, with further increase of heat generation, the UTS decreases and reaches MPa for specimen. Therefore, there was an optimum range for heat generation, which affected the UTS; in fact, the heat generation affected IMCs formation in FSWed joints between aluminum and copper [ 36 ].
Consequently, the UTS value decreases. For specimen, the traverse speed was relatively high, so that the mixing and flow of material between aluminum and copper did not occur appropriately. Consequently, many defects such as macro-cracks, tunnels and holes were created at the interface between aluminum and copper [ 17 ].
Regarding the mentioned phenomenon, brittle fracture occurred in the SZ and interface between aluminum and copper. For specimens, the mixing and flow of the material between aluminum and copper were taken place appropriately. Due to the finer grain size, the tensile strength increased [ 17 ]. Moreover, due to the lower heat generation, the amount of the intermetallic compounds was less than the other specimens [ 5 , 17 , 19 ]. Fine copper particles were a composite-like structure, and finer pieces of copper distributed in the aluminum matrix [ 4 , 13 , 18 ].
During the tensile test, dislocations should circumvent the copper pieces leading to an increase in tensile strength.
The fracture mechanism in the TMAZ is related to the dislocation movement. Since the density of dislocation was high, in the course of tensile test, the dislocations are more quickly piled up as compared to the base metals. Consequently, the ductile fracture occurred in TMAZ [ 37 , 38 ]. For , and specimens, by increasing heat generation, the mixing rate and material flow between aluminum and copper were enhanced.
As a result, the amount of IMCs increased and, therefore, the tensile properties lowered. The mechanical properties and microstructural characterization of FSWed joints of AA aluminum alloy to copper were investigated by Liu et al. On the other hand, it was found that, by increasing heat generation, the grain size increased. These issues led to reduction of the tensile strength. In addition, in the case of and specimens, the fracture occurs in SZ of aluminum and, in specimen, fracture occurs in SZ and at the interface between aluminum and copper.
The fracture of specimen from interface confirmed the presence of large amounts of IMCs in this joint. Figure 14 shows the fracture surfaces of all FSWed specimens studied. In general, the failure mode of dissimilar joints between aluminum and copper can be stated as a brittle and ductile mixed mode, which is reported by some of the researchers [ 13 , 19 , 26 ]. Here, fracture surfaces were studied by SEM. For specimen, no dimples were observed on fracture surface because inadequate mixing occurs between aluminum and copper.
Hence, this specimen failed in a brittle mode. For and specimens, large number of dimples were observed on fracture surface, meaning that these specimens failed in a ductile mode. However, for and specimens Fig. Hence, these specimens seem to fail in mixed mode. So, the brittle fracture is more dominant for and specimens. In this case, by increasing the heat generation, the fracture mode moves to the brittle mode, because of the increased amount of IMCs and their brittle nature. Figure 15 shows the results of XRD from the fracture surfaces of and specimens.
It indicated the presence of IMCs in weld joints. In fact, for specimen, the fracture is related to both the motion of dislocations and the formation of IMCs in TMAZ, while for specimen, the IMCs formation is the main factor for fracture. In this study, butt FSW was carried out between AAH and commercial pure copper with 1-mm offset tool to the aluminum from the butt centerline. Effect of heat generation on the mechanical properties and microstructure of FSWed joints was studied. Based on the results obtained, the following concluding remarks can be achieved:.
The macrostructures of the FSWed specimens showed the lamellar layer in the SZ consisting of aluminum, copper pieces and intermetallic compounds. Also dispersion of fine copper pieces in stir zone, as a composite-like structure, was observed. Hence, the grain size becomes smaller than that of the base metal. Increasing heat generation led to an increase in the grain size and amount of intermetallic compounds. The intermetallic compounds formed in the joints were proposed to be Al2Cu and Al4Cu9. The grain size and formation of intermetallic compounds were found to determine the mechanical properties of FSWed joints.
Also the values of the yield strength and the percentage of elongation were equal to MPa and 6. In addition, the ductile fracture occurred in TMAZ. The microhardness of FSWed joints between aluminum and copper was directly related to the grain size, the intermetallic compounds formed and dispersion of fine copper pieces. Maximum value of micro-hardness in SZ was about HV. Acta Metallurgica Sinica English Letters , , 31 11 : Abstract : In this study, the dissimilar friction stir welding FSW butt joints between aluminum alloy H and commercially pure copper were investigated.
Key words : Friction stir welding ; H aluminum alloy ; Pure copper ; Heat generation ; Microstructure ; Intermetallic compounds. Table 2 Welding parameters and the FSWed specimens. View Option. Mishra , Z. Ma , Mater. Firouzdor , S. Kou , Weld. J 88 , Bozzi , A. Helbert-Etter , T. Baudin , B. Criqui , J. Kerbiguet , Mater. Esmaeili , M. Givi , H. Rajani , Mater. Sinha , S. Kundu , S. Chatterjee , Perspect. Sahu , S. Pal , S. Pal , R. Jain , J. Muthu , V. Jayabalan , Trans. Metals Soc. China 26, Mubiayi , E. Akinlabi , Trans. Zhang , W. Gong , L. Wei , Trans. China 25, Akinlabi , A.
Andrews , S. China 24, Tan , Z. Jiang , L. Chen , X. Chen , Mater.
Liu , Q. Shi , W. Wang , X. Wang , Z. Zhang , Mater. Galvao , J. Oliveira , A. Loureiro , D. Rodrigues , Sci. Rodrigues , Intermet 22, Kush P. Mehta , Vishvesh J. Xue , B. Xiao , D. Ma , Sci. Bisadi , A. Tavakoli , M. Sangsaraki , K. Sangsaraki , Mater. Pishevar , J. Mohandesi , H. Omidvar , M. Safarkhanian , J. Chen , H. Ding , J. Zhao , M. Li , Trans. Lotfalian Saremi , S.
Mirsalehi , A. Shamsipur , Trans. Metals 70, Zhang , Q. Cheng , W. Zhang , Trans. China 22, Meyghani , M. Awang , S. Emamian , M. Mohd Nor , S. Pedapati , Metals 7 , Sanjeev , V. Malik , H. Hebbar , Int. Ouyang , E. Yarrapareddy , R.
Kovacevic , J. Liu , J. Shen , L. Zhou , Y. Zhao , C. Liu , L. Kuang , Sci. Kim , S. Kim , J.
Lee , M. Choi , S. Choe , K. Ryu , S.
Han , W. Kim , Acta Mater. Lee , K. Bang , S. Jung , J. Alloys Compd. Akinlabi , J. Mehta , V. Badheka , Mater. Shojaei-Zoeram , S. Mousavi-Anijdan , H. Jafarian , T. This is because cold working builds up dislocations and vacancies in the structure, which then inhibits the movement of atoms relative to each other.
This increases the strength of the metal. Alloying elements like magnesium intensify this effect, resulting in even higher strength. Manganese is the major alloying element in this series, often with smaller amounts of magnesium added. However, only a limited percentage of manganese can be effectively added to aluminum. Alloy and its modifications are used in the bodies of aluminum beverage cans.
Because of this, the 4xxx series produces excellent welding wire and brazing alloys where a lower melting point is required. Alloy is one of the most widely used filler alloys for welding 6xxx series alloys for structural and automotive applications. Magnesium is the primary alloying agent in the 5xxx series and is one of the most effective and widely used alloying elements for aluminum. Alloys in this series possess moderate to high strength characteristics, as well as good weldablility and resistance to corrosion in the marine environment.
Because of this, aluminum-magnesium alloys are widely used in building and construction, storage tanks, pressure vessels and marine applications. Examples of common alloy applications include: in electronics, in marine applications, anodized sheet for architectural applications and makes the aluminum beverage can lid. The U. Three years later, the system was approved as American National Standard H This designation system was officially adopted by the International Signatories of the Declaration of Accord in and became an international designation system.
The Association has served as the major standard setting organization for the global aluminum industry ever since. The whole process, from registering a new alloy to assigning a new designation, takes between 60 to 90 days. When the current system was originally developed in , the list included 75 unique chemical compositions. Today, there are more than registered active compositions and that number continues to grow.
That underscores how versatile and ubiquitous aluminum has become in our modern world. Otherwise, you agree to the use of the cookies as they are currently set. Skip to main content. Google Tag Manager. Remember me. Request new password. Search form Search. The Aluminum Advantage. Aluminum Advantage.
Product Markets. Members Area. Buyer's Guide. Aluminum Alloys Quick Read An aluminum alloy is a chemical composition where other elements are added to pure aluminum in order to enhance its properties, primarily to increase its strength. Bradley Fighting Vehicle The military Bradley Fighting Vehicle is made from two different aluminum alloys: a 7xxx series and 5xxx series.
Trusted to keep soldiers safe and mobile, aluminum is also used in many other military vehicles. The shell of the can is composed of and the lid is made from Sometimes it takes more than one alloy to make one, everyday item. Hot and Cold Aluminum alloys can be made stronger through heat-treatment or cold working. The attributes of a particular alloy are different because of their additives and treatment.