Investigation of forming limit diagram and mechanical properties of the bimetallic Al/Cu composite sheet at different temperatures which fabricated by explosive welding

Author(s):  
Ali Alaie ◽  
Ramin Hashemi ◽  
Farshad Kazemi

This research aims to investigate the mechanical properties, fractography and formability of Al/Cu two-layer composite sheets at three temperatures (23 °C, 120 °C and 220 °C). The bimetal sheet was fabricated by the explosive welding method. The anisotropy of the Al/Cu bimetallic composite sheet was investigated. The result showed significant anisotropy in the Al/Cu composite sheet due to the explosive welding process. The Vickers hardness measurements demonstrated that the hardness in both aluminum and copper sides increased because of the work hardening phenomenon. The fractography of the surfaces was investigated by the scanning electron microscope after tensile tests to study the effect of temperature and the direction, which the samples prepared for the tensile test with respect to the explosion direction, on the mechanism of the fracture. For the tensile test, the samples were prepared parallel to the detonation direction [Formula: see text] and two other directions with respect to the explosion direction [Formula: see text] from the AA1100/Cu10100 bimetallic sheet. Finally, the forming limit diagram of the Al/Cu composite sheet was determined at the three mentioned temperatures. The results demonstrated that temperature and the direction had a considerable effect on the mechanism of the rupture and formability. As the temperature of the specimen rises, the regions that brittle fracture happened became less and the formability improved significantly. The formability of the Al/Cu composite sheet enhanced about 34.8% when the temperature increased from 23 °C to 120 °C and 67.5% when it increased from 120 °C to 220 °C.

2007 ◽  
Vol 129 (4) ◽  
pp. 530-537 ◽  
Author(s):  
M. Weiss ◽  
M. E. Dingle ◽  
B. F. Rolfe ◽  
P. D. Hodgson

The influence of temperature on the forming behavior of an aluminum/polypropylene/aluminum (APA) sandwich sheet was studied. Shear and tensile tests were performed to determine the mechanical properties of the laminate and the component materials as a function of process temperature. The forming limit diagram (FLD) of the laminate was established for two different temperatures, and its springback behavior was examined in four-point bend and channel bend tests. Cup forming tests were performed at various test temperatures to determine the limiting drawing ratio (LDR) and the tendency for wrinkling at these temperatures. Although there was only a minor influence of temperature on the mechanical properties and the FLD values of the laminate, the bend test results reveal that springback can be reduced by forming at higher temperature. The decreasing strength of the core material with rising process temperature led to an increased tendency of the laminate to wrinkle in the heated cup drawing tests.


2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.


1999 ◽  
Author(s):  
Takeru Ohki ◽  
Shinya Ikegaki ◽  
Ken Kurasiki ◽  
Hiroyuki Hamada ◽  
Masaharu Iwamoto

Abstract In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two type of specimens were prepared. They are a braided flat bar with an integrally-formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole.


1992 ◽  
Vol 73 (3) ◽  
pp. 1171-1180 ◽  
Author(s):  
J. C. Debes ◽  
Y. C. Fung

The influence of temperature on the mechanical properties of excised saline-filled lung parenchyma of the dog was studied at low lung volume. The motivation of this study was to determine whether lung tissue material without the influence of surface tension undergoes a phase transition in the 20–40 degrees C range, as does synthetic elastin studied by Urry in 1984–1986. Dynamic biaxial and uniaxial tensile tests were done, and strain vs. Lagrangian stress curves were recorded during slow cooling and heating between 40 and 10 degrees C. To emphasize the effects of elastin, strains (defined as stretch ratio minus one) were kept below 30%. A slight decrease in compliance occurred with cooling over the entire temperature range. This effect may be attributed to collagen. It was accompanied by a gradual increase in length as the tissue cooled, an effect that may be attributed to elastin. This process was partially reversible with reheating. However, this effect is in contrast with the sudden drastic change in mechanical properties of synthetic elastin described by Urry. Hysteresis, creep, and stress relaxation were small at these low strains. Possible causes of these effects are discussed.


Author(s):  
J. Brnic ◽  
M. Canadija ◽  
G. Turkalj ◽  
D. Lanc

In this paper, some interesting, experimentally determined actualities referring to the 50CrMo4 steel are presented. That way, the mechanical properties of the material are derived from uniaxial tensile tests at lowered and elevated temperatures. Engineering stress versus strain diagrams for both mentioned temperatures, curves representing the effect of temperature on specimen elongation, and short-time creep curves are given. Notch impact energy test was also carried out. Taking into consideration the service life of the final product of the mentioned steel widely used in engine and machine technology, all of the mentioned data may be relevant during design and manufacturing procedure.


2000 ◽  
Vol 122 (4) ◽  
pp. 420-424 ◽  
Author(s):  
Takeru Ohki ◽  
Shinya Ikegaki ◽  
Ken Kurasiki ◽  
Hiroyuki Hamada ◽  
Masaharu Iwamoto

In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two types of specimen were prepared. They are a braided flat bar with an integrally formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole. [S0094-4289(00)02604-9]


Author(s):  
Behrouz Bagheri ◽  
Mahmoud Abbasi ◽  
Reza Hamzeloo

A tailor welded blank (TWB) includes two or more blanks joined together in order to make a single blank. Different welding methods are used to join blanks with different characteristics and form TWBs. In this study, a comparison is made among the effects of three different welding methods namely CO2 laser welding, friction stir welding (FSW), and friction stir vibration welding (FSVW) on mechanical and formability properties of developed TWBs. AA6061 alloy sheets with different thicknesses (1.2 and 0.8 mm) are joined to get TWBs. The forming limit diagram (FLD) and limiting dome height (LDH) are applied to assess the formability. The Taguchi method is applied to find the optimum values of welding parameters. It is concluded that TWBs made by FSVW have higher mechanical properties and formability compared to TWBs made by FSW and CO2 laser welding. The results also indicate that FLD for TWBs made by FSW is higher than FLD for TWBs made by CO2 laser welding and FLD0, for TWBs made by FSVW, increases as vibration frequency increases.


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