Influence of Equal-Channel Angular Pressing on the Superplastic Properties of Commercial Aluminum Alloys

1999 ◽  
Vol 601 ◽  
Author(s):  
Sungwon Lee ◽  
Terence G. Langdon
Keyword(s):  
Aluminum Alloys ◽  
Strain Rate ◽  
Tensile Testing ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
High Strain ◽  
Optimum Temperature ◽  
Angular Pressing ◽  
Superplastic Properties ◽  
Al 2024

AbstractEqual-channel angular (ECA) pressing was used to refine the microstructure in two commercial aluminum alloys, Al-2024 and the Supral-100 Al-2004 alloy. The ECA pressing was conducted at room temperature and at elevated temperatures for both alloys using several different processing routes. Tensile testing was carried out at elevated temperatures on both pressed and unpressed samples of each alloy in order to evaluate the effect of the pressing. This paper describes the influence of the ECA pressing on the subsequent mechanical properties of these two alloys. For both alloys, it is shown that the optimum superplastic conditions are influenced by the ECA pressing, and in practice there tends to be a decrease in the optimum temperature for superplasticity and a corresponding increase in the optimum strain rate. In addition, there was evidence for high strain rate superplasticity (HSR SP) in both alloys after the ECA pressing procedure.

Experimental and numerical analysis of high strain rate behavior of aluminum alloys AMg-6 and D-16

2006 ◽  
Vol 134 ◽  
pp. 487-491 ◽  
Author(s):  
A. V. Abramov ◽  
A. M. Bragov ◽  
A. K. Lomunov ◽  
A. Yu. Konstantinov ◽  
L. Kruszka ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Aluminum Alloys ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Rate Behavior ◽  
Strain Rate Behavior ◽  
High Strain Rate Behavior

scholarly journals Specimen Inertia in high strain rate tensile testing

2015 ◽  
Vol 94 ◽  
pp. 01050 ◽  
Author(s):  
Meyrick Hockly ◽  
Clive R. Siviour
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Tensile Testing ◽  
High Strain

Local Investigations of the Mechanical Properties of Ultrafine Grained Metals by Nanoindentations

2006 ◽  
Vol 503-504 ◽  
pp. 31-36 ◽  
Author(s):  
Johannes Mueller ◽  
Karsten Durst ◽  
Dorothea Amberger ◽  
Matthias Göken
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Room Temperature ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Fcc Metals ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Indentation Strain

The mechanical properties of ultrafine-grained metals processed by equal channel angular pressing is investigated by nanoindentations in comparison with measurements on nanocrystalline nickel with a grain size between 20 and 400 nm produced by pulsed electrodeposition. Besides hardness and Young’s modulus measurements, the nanoindentation method allows also controlled experiments on the strain rate sensitivity, which are discussed in detail in this paper. Nanoindentation measurements can be performed at indentation strain rates between 10-3 s-1 and 0.1 s-1. Nanocrystalline and ultrafine-grained fcc metals as Al and Ni show a significant strain rate sensitivity at room temperature in comparison with conventional grain sized materials. In ultrafine-grained bcc Fe the strain rate sensitivity does not change significantly after severe plastic deformation. Inelastic effects are found during repeated unloading-loading experiments in nanoindentations.

High Strain Rate Superplasticity in a Zr and Sc Modified 7075 Aluminum Alloy Produced by ECAP

2008 ◽  
Vol 584-586 ◽  
pp. 164-169 ◽  
Author(s):  
Krystof Turba ◽  
Premysl Malek ◽  
Edgar F. Rauch ◽  
Miroslav Cieslar
Keyword(s):  
Aluminum Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Rate Sensitivity ◽  
7075 Aluminum Alloy ◽  
Fine Grained ◽  
Angular Pressing ◽  
Average Grain Size ◽  
Elongation To Failure

Equal-channel angular pressing (ECAP) at 443 K was used to introduce an ultra-fine grained (UFG) microstructure to a Zr and Sc modified 7075 aluminum alloy. Using the methods of TEM and EBSD, an average grain size of 0.6 1m was recorded after the pressing. The UFG microstructure remained very stable up to the temperature of 723 K, where the material exhibited high strain rate superplasticity (HSRSP) with elongations to failure of 610 % and 410 % at initial strain rates of 6.4 x 10-2 s-1 and 1 x 10-1 s-1, respectively. A strain rate sensitivity parameter m in the vicinity of 0.45 was observed at temperatures as high as 773 K. At this temperature, the material still reached an elongation to failure of 430 % at 2 x 10-2 s-1. These results confirm the stabilizing effect of the Zr and Sc additions on the UFG microstructure in a 7XXX series aluminum alloy produced by severe plastic deformation.

Strength of Commercial Aluminum Alloys after Equal Channel Angular Pressing and Post-ECAP Processing

2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloys ◽  
Ultimate Tensile Strength ◽  
Equal Channel Angular Pressing ◽  
Room Temperature ◽  
Solution Treatment ◽  
Ecap Processing ◽  
Angular Pressing

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.

Tensile Ductility of Ultra-Fine Grained Copper at High Strain Rate

2010 ◽  
Vol 160-162 ◽  
pp. 260-266 ◽  
Author(s):  
Tao Suo ◽  
Kui Xie ◽  
Yu Long Li ◽  
Feng Zhao ◽  
Qiong Deng
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Testing Machine ◽  
Coarse Grained ◽  
Dislocation Dynamic ◽  
Pressing Method ◽  
Fine Grained ◽  
Angular Pressing ◽  
Split Hopkinson

In this paper, ultra-fine grained copper fabricated by equal channel angular pressing method and annealed coarse grained copper were tensioned under both quasi-static and dynamic loading conditions using an electronic universal testing machine and the split Hopkinson tension bar respectively. The rapture surface of specimen was also observed via a Scanning Electron Microscope (SEM). The experimental results show that the ductility of polycrystalline copper decreases remarkably due to the grain refinement. However, with the increase of applied strain rate, ductility of the UFG-Cu is enhanced. The fracture morphologies also give the evidence of enhanced ductility of UFG-Cu at high strain rate. It is believed the enhanced ductility of UFG materials at high strain rate can be attributed to the restrained dislocation dynamic recovery.

Fatigue Lifetime Improvement of Aluminum Alloys

2019 ◽  
Author(s):  
Patiphan Juijerm ◽  
Berthold Scholtes
Keyword(s):  
Aluminum Alloys ◽  
Surface Treatment ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Deep Rolling ◽  
Fatigue Lifetime ◽  
Mechanical Surface Treatment ◽  
Strong Candidate ◽  
And Behavior ◽  
Mechanical Surface

Today, aluminum alloys are being considered as substitutes for many automotive parts made from steels because of the growing interest in producing lightweight vehicles. Consequently, it is crucial to understand the fatigue lifetime—the property itself and its behavior—of aluminum alloys, and to clarify its capacities at both room temperature and 1001 elevated temperatures. In particular, the aluminum alloys in the AA5xxx (non-precipitation-hardenable) and AA6xxx (precipitation-hardenable) series are very similar to those found in automotive industries, and are both frequently mentioned and the focus of studies. The satisfactory fatigue lifetime and the improved strength of aluminum alloys make them a strong candidate for automotive industries. This article focuses upon the fatigue property and behavior of aluminum alloys at room temperature and elevated temperatures. Then, the focus will shift to the concept of mechanical surface treatment, the so-called deep-rolling process, which can be used to improve the fatigue lifetime of aluminum alloys. The effects of a mechanical surface treatment on the fatigue properties and behavior of the aluminum alloys AA5083 and AA6110, and the residual stress stability at room temperature and elevated temperatures has been discussed. Moreover, modified deep-rolling processes, i.e., deep-rolling followed by an appropriate annealing process and high-temperature deep-rolling, have been elaborated upon in this article.

scholarly journals Comparison of Mechanical and Microstructural Properties of as-Cast Al-Cu-Mg-Ag Alloys: Room Temperature vs. High Temperature

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1330
Author(s):  
Muhammad Farzik Ijaz ◽  
Mahmoud S. Soliman ◽  
Ahmed S. Alasmari ◽  
Adel T. Abbas ◽  
Faraz Hussain Hashmi
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Mechanical Testing ◽  
Tensile Testing ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Microstructural Properties ◽  
Testing Environments ◽  
Mechanical And Microstructural Properties ◽  
Mg Content

Unfolding the structure–property linkages between the mechanical performance and microstructural characteristics could be an attractive pathway to develop new single- and polycrystalline Al-based alloys to achieve ambitious high strength and fuel economy goals. A lot of polycrystalline as-cast Al-Cu-Mg-Ag alloy systems fabricated by conventional casting techniques have been reported to date. However, no one has reported a comparison of mechanical and microstructural properties that simultaneously incorporates the effects of both alloy chemistry and mechanical testing environments for the as-cast Al-Cu-Mg-Ag alloy systems. This preliminary prospective paper presents the examined experimental results of two alloys (denoted Alloy 1 and Alloy 2), with constant Cu content of ~3 wt.%, Cu/Mg ratios of 12.60 and 6.30, and a constant Ag of 0.65 wt.%, and correlates the synergistic comparison of mechanical properties at room and elevated temperatures. According to experimental results, the effect of the precipitation state and the mechanical properties showed strong dependence on the composition and testing environments for peak-aged, heat-treated specimens. In the room-temperature mechanical testing scenario, the higher Cu/Mg ratio alloy with Mg content of 0.23 wt.% (Alloy 1) possessed higher ultimate tensile strength when compared to the low Cu/Mg ratio with Mg content of 0.47 wt.% (Alloy 2). From phase constitution analysis, it is inferred that the increase in strength for Alloy 1 under room-temperature tensile testing is mainly ascribable to the small grain size and fine and uniform distribution of θ precipitates, which provided a barrier to slip by deaccelerating the dislocation movement in the room-temperature environment. Meanwhile, Alloy 2 showed significantly less degradation of mechanical strength under high-temperature tensile testing. Indeed, in most cases, low Cu/Mg ratios had a strong influence on the copious precipitation of thermally stable omega phase, which is known to be a major strengthening phase at elevated temperatures in the Al-Cu-Mg-Ag alloying system. Consequently, it is rationally suggested that in the high-temperature testing scenario, the improvement in mechanical and/or thermal stability in the case of the Alloy 2 specimen was mainly due to its compositional design.

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