Tensile Properties and Strain Hardening Behavior of a Friction Stir Welded AA2219 Al Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 833-840 ◽  
Author(s):  
Wei Feng Xu ◽  
Jin He Liu ◽  
Dao Lun Chen ◽  
Guo Hong Luan ◽  
Jun Shan Yao
Keyword(s):  
Strain Hardening ◽  
Tensile Properties ◽  
Base Metal ◽  
Boundary Phase ◽  
Strain Hardening Exponent ◽  
Al Alloy ◽  
Second Phase ◽  
Premature Failure ◽  
Friction Stir ◽  
Hardening Behavior

Microstructures, tensile properties and work hardening behavior of friction stir welded (FSWed) AA2219-T62 aluminum alloy (in its one-third bottom slice of a 20 mm thick plate) were evaluated at different strain rates. While the yield strength was lower in the FSWed joint than in the base metal, the ultimate tensile strength of the FSWed joint approached that of the base metal. In particular the FSW resulted in a significant improvement in the ductility of the alloy due to the prevention of premature failure caused by intergranular cracking along the second-phase boundary related to the presence of the network-like grain boundary phase in the base metal. While stage III and IV hardening occurred after yielding in both base metal and FSWed samples, the FSW led to stronger hardening capacity and higher strain hardening exponent and rate due to the enhanced dislocation storage capacity associated with the microstructural change after FSW. The fracture surface of the FSWed joint was mainly characterized by dimples and tearing ridges along with micropores.

scholarly journals Cold-Rolling Strain Hardening Effect on the Microstructure, Serration-Flow Behaviour and Dislocation Density of Friction Stir Welded AA5083

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 70 ◽  
Author(s):  
Zainuddin Sajuri ◽  
Nor Fazilah Mohamad Selamat ◽  
Amir Hossein Baghdadi ◽  
Armin Rajabi ◽  
Mohd Zaidi Omar ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Dislocation Density ◽  
Cold Rolling ◽  
Strain Hardening ◽  
Base Metal ◽  
Welded Joint ◽  
Flow Behaviour ◽  
Al Alloy ◽  
Stress Strain ◽  
Friction Stir

5083 aluminium (Al) alloy materials have extensive structural applications in transportation industries because of their high strength-to-weight ratio and corrosion resistance. However, under conventional fusion weldings, these materials are limited by their porosity, hot cracking, and distortion. Herein, friction stir welding (FSW) was performed to join a similar AA5083 alloy. A post-weld cold-rolling (PWCR) process was applied on joint samples at different thickness-reduction percentages (i.e., 10%, 20%, and 40%) to identify the effect of strain hardening on the microstructure and mechanical properties of the friction-stir-welded joint of AA5083 while considering the serration-flow behaviour at stress–strain curves and dislocation density of the post-weld cold-rolled (PWCRed) samples. FSW induced a 20% reduction in the tensile strength of the joint samples relative to the base metal. PWCR also reduced the average grain size at the nugget zone and base metal because of the increase in plastic deformation imposed on the samples. Furthermore, PWCR increased the dislocation density because of the interaction among dislocation stress fields. Consequently, the tensile strength of the friction-stir-welded joint increased with the increased cold-rolling percentage and peaked at 403 MPa for PWCRed–40%, which significantly improved the serration-flow behaviour of stress–strain and welding efficiency up to 123%.

scholarly journals Effect of Grain Size on the Microstructure and Strain Hardening Behavior of Solution Heat-Treated Low-C High-Mn Steel

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1489 ◽  
Author(s):  
Marek Opiela ◽  
Gabriela Fojt-Dymara ◽  
Adam Grajcar ◽  
Wojciech Borek
Keyword(s):  
Grain Size ◽  
Strain Hardening ◽  
Strengthening Mechanism ◽  
Strength Properties ◽  
Low Carbon ◽  
Premature Failure ◽  
Hardening Behavior ◽  
Heat Treated ◽  
Strain Hardening Behavior ◽  
Grain Diameter

The low-carbon high-Mn austenitic steel microalloyed with titanium was investigated in this work. The steel was solution heat-treated at different temperatures in a range from 900 to 1200 °C. The aim was to receive a different grain size before the static tensile test performed at room temperature. The samples of different grain sizes showed the different strain hardening behavior and resulting mechanical properties. The size of grain diameter below 19 μm was stable up to 1000 °C. Above this temperature, the very enhanced grain growth took place with the grain diameter higher than 220 μm at 1200 °C. This huge grain size at the highest temperature resulted in the premature failure of the sample showing the lowest strength properties at the same time. Correlations between the grain size, the major strengthening mechanism, and fracture behavior were addressed. The relationships were assessed based on microstructural investigations and fractography tests performed for the deformed samples. The best combination of strength and ductility was found for the samples treated at 1000–1100 °C.

Assessment of Microstructure and Wear Resistance of Friction Stir Processed Cast Mg-Al-Zn Magnesium Alloy

2015 ◽  
Vol 787 ◽  
pp. 442-447 ◽  
Author(s):  
R. Jayaraman ◽  
T. Balusamy ◽  
A.K. Lakshminarayanan
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Base Metal ◽  
Second Phase ◽  
Micro Hardness ◽  
Friction Stir ◽  
Second Phase Particles ◽  
Metal Wear ◽  
Pin On Disc ◽  
Cast Magnesium

Microstructure, micro hardness and wear resistance of friction stir processed cast magnesium alloy are investigated in this work. Image analysis is used to differentiate the amount of phases present in the base metal and friction stir processed regions. Hardness mapping indicates that the frictions stir processed region has 64 % increase in microhardness compared to the base metal. Wear resistance was evaluated using pin-on-disc testing and it is found that the friction stir processed region has superior wear resistance compared to the base metal. Fine grains with uniformly distributed second phase particles are the reasons for improved microhardness and wear resistance of friction stir processed region.

Investigating the Effect of Miniaturization on the Microtensile Properties of Brass (CuZn30)

2011 ◽  
Author(s):  
Lauren B. Wuertemberger ◽  
Megan N. Chann ◽  
Richard M. Onyancha
Keyword(s):  
Strain Hardening ◽  
Tensile Properties ◽  
Material Properties ◽  
Tensile Tests ◽  
Strain Hardening Exponent ◽  
Manufacturing Processes ◽  
Strength Coefficient ◽  
Grain Sizes ◽  
Heat Treated ◽  
Average Grain Size

As everyday equipment becomes smaller and smaller, it is of increasing importance that the manufacturing processes used for metals are capable of producing parts of appropriate sizes. Currently, manufacturing processes assume macromaterial properties can be applied for microscale production, but is this a valid assumption? This paper investigates the accuracy of applying macroscale tensile properties in microscale applications. In order to test the soundness of this supposition, tensile tests were performed on both macroscale and microscale brass specimens, and the resulting calculated material properties, strain hardening exponent (n) and strength coefficient (K), were compared. Specimens were heat treated to various temperatures before tensile tests were performed, and the strength coefficient and strain hardening exponents of micro and macro tensile specimens were compared. Additionally, it is investigated whether average grain size correlates to material properties. The results showed that in general it is not accurate to apply macroscale tensile properties to microscale applications. However, at mesocale grain sizes, (12–20 microns), the strain hardening exponent values were similar for both macro and microscale specimens.

THREE-DIMENSIONAL SIMULATION OF DEFORMATION FIELDS UNDERNEATH VICKERS INDENTER: EFFECTS OF POWER-LAW PLASTICITY

2010 ◽  
Vol 24 (01n02) ◽  
pp. 238-246 ◽  
Author(s):  
NUWONG CHOLLACOOP ◽  
UPADRASTA RAMAMURTY
Keyword(s):  
Yield Strength ◽  
Strain Hardening ◽  
Power Law ◽  
Strain Distribution ◽  
Three Dimensional ◽  
Strain Hardening Exponent ◽  
Al Alloy ◽  
Element Analysis ◽  
Vickers Indenter ◽  
Experimental Heat

The effects of power-law plasticity (yield strength and strain hardening exponent) on the plastic strain distribution underneath a Vickers indenter was systematically investigated by recourse to three-dimensional finite element analysis, motivated by the experimental macro- and micro-indentation on heat-treated Al - Zn - Mg alloy. For meaningful comparison between simulated and experimental results, the experimental heat treatment was carefully designed such that Al alloy achieve similar yield strength with different strain hardening exponent, and vice versa. On the other hand, full 3D simulation of Vickers indentation was conducted to capture subsurface strain distribution. Subtle differences and similarities were discussed based on the strain field shape, size and magnitude for the isolated effect of yield strength and strain hardening exponent.

Mechanical tensile properties by spherical macroindentation using an indentation strain-hardening exponent

2013 ◽  
Vol 75 ◽  
pp. 257-264 ◽  
Author(s):  
M. Yetna N’Jock ◽  
D. Chicot ◽  
X. Decoopman ◽  
J. Lesage ◽  
J.M. Ndjaka ◽  
...  
Keyword(s):  
Strain Hardening ◽  
Tensile Properties ◽  
Strain Hardening Exponent ◽  
Mechanical Tensile ◽  
Indentation Strain
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