Improvement of mechanical properties of a nanoaluminium alloy by precipitate strengthening

2012 ◽  
Vol 57 (3) ◽  
pp. 877-881 ◽  
Author(s):  
K. Wawer ◽  
M. Lewandowska ◽  
K.J. Kurzydłowski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Precipitation Strengthening ◽  
Post Processing ◽  
Heat Treated ◽  
Precipitate Strengthening

In the present study, severe plastic deformation (SPD) processing was combined with pre- and post processing heat treatment to investigate the possibility of synergic grain size and precipitation strengthening. Samples of 7475 alloy were solution heat treated and water quenched prior to hydrostatic extrusion (HE) which resulted in a grain refinement by 3 orders of magnitude, from 70 μm to about 70 nm. The extruded samples were subsequently aged at temperatures resulting in formation of nanoprecipitates.

Improvement of Mechanical Properties and Microstructure of Al-Fe-Si Alloy by ECAP Semisolided Method

2010 ◽  
Author(s):  
D. Azimi-Yancheshmeh ◽  
M. Aghaie-Khafri
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Solid Phase ◽  
High Strength ◽  
Ultrafine Grains ◽  
Ecap Process ◽  
Hardness Tests ◽  
Heat Treated

ECAP is one of the Severe Plastic Deformation methods for reducing the grain size. With this process we can achieve ultrafine grains and consequently high strength. In this study, ECAP process was done on Al-Fe-Si alloy. This alloy was considered because of Fe effect on refining grain size. All samples were ECAPed into 1 pass in ECAP mold with 2 equal channels (1 cm × 1 cm) with 90 degree between them. By this method, around 1.05 as strain was applied on each samples. ECAPed specimens were heat treated (Semisolided) in different times and temperatures for achieving good toughness. Compression and hardness tests were done for finding the mechanical properties. As a result of these test, specimens that tolerate both ECAP and Semisolid have better toughness and strength than received and only ECAPed samples. Based on the microstructural evaluations spheroid solid phase was observed in the Semisolid specimen.

From Micro to Nano Scale Structure by Plastic Deformations

2014 ◽  
Vol 783-786 ◽  
pp. 842-847 ◽  
Author(s):  
Tibor Kvačkaj ◽  
Jana Bidulská
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Structure Refinement ◽  
Austenite Formation ◽  
Structural Refinement ◽  
Plastic Deformations ◽  
Austenitic Grain Size

Nowadays, the strategy for improving of mechanical properties in metals is not oriented to alloying followed by heat treatment. An effective way how to improve the mechanical properties of metals is focused on the research looking for some additional structural abilities of steels. Structural refinement is one of the ways. Refinement of the austenitic grain size (AGS) carried out through plastic deformation in a spontaneous recrystallization region of austenite, formation of AGS by plastic deformations in a non-recrystallized region of austenite will be considered as potential ways for AGS refinement. After classic methods of plastic deformations, next structure refinement can be obtained by an application of severe plastic deformation (SPD) methods.

scholarly journals Influence of Post Weld Heat Treatment on the Grain Size, and Mechanical Properties of the Alloy-800H Rotary Friction Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Heat Affected Zone ◽  
Tensile Testing ◽  
Weld Zone ◽  
Alloy 800H ◽  
Weld Joints ◽  
Heat Treated ◽  
Friction Weld

This study evaluated the microstructure, grain size, and mechanical properties of the alloy 800H rotary friction welds in as-welded and post-weld heat-treated conditions. The standards for the alloy 800H not only specify the composition and mechanical properties but also the minimum grain sizes. This is because these alloys are mostly used in creep resisting applications. The dynamic recrystallization of the highly strained and plasticized material during friction welding resulted in the fine grain structure (20 ± 2 µm) in the weld zone. However, a small increase in grain size was observed in the heat-affected zone of the weldment with a slight decrease in hardness compared to the base metal. Post-weld solution heat treatment (PWHT) of the friction weld joints increased the grain size (42 ± 4 µm) in the weld zone. Both as-welded and post-weld solution heat-treated friction weld joints failed in the heat-affected zone during the room temperature tensile testing and showed a lower yield strength and ultimate tensile strength than the base metal. A fracture analysis of the failed tensile samples revealed ductile fracture features. However, in high-temperature tensile testing, post-weld solution heat-treated joints exhibited superior elongation and strength compared to the as-welded joints due to the increase in the grain size of the weld metal. It was demonstrated in this study that the minimum grain size requirement of the alloy 800H friction weld joints could be successfully met by PWHT with improved strength and elongation, especially at high temperatures.

Structure and Hardness of Cryorolled and Heat-Treated 2xxx Aluminum Alloy

2010 ◽  
Vol 667-669 ◽  
pp. 925-930
Author(s):  
S.V. Krymskiy ◽  
Elena Avtokratova ◽  
M.V. Markushev ◽  
Maxim Yu. Murashkin ◽  
O.S. Sitdikov
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Severe Plastic Deformation ◽  
Coarse Grained ◽  
Aging Response ◽  
Heat Treated ◽  
Aluminum Solid Solution ◽  
A Cell

The effects of severe plastic deformation (SPD) by isothermal rolling at the temperature of liquid nitrogen combined with prior- and post-SPD heat treatment, on microstructure and hardness of Al-4.4%Cu-1.4%Mg-0.7%Mn (D16) alloy were investigated. It was found no nanostructuring even after straining to 75%. Сryodeformation leads to microshear banding and processing the high-density dislocation substructures with a cell size of ~ 100-200 nm. Such a structure remains almost stable under 1 hr annealing up to 200oC and with further temperature increase initially transforms to bimodal with a small fraction of nanograins and then to uniform coarse grained one. It is found the change in the alloy post–SPD aging response leading to more active decomposition of the preliminary supersaturated aluminum solid solution, and to the alloy extra hardening under aging with shorter times and at lower temperatures compared to T6 temper.

Computation on continuous grain refinement in AA1050 aluminum during repetitive tube expansion and shrinking technique

2015 ◽  
Vol 232 (4) ◽  
pp. 307-318
Author(s):  
H Jafarzadeh ◽  
K Abrinia
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Grain Size ◽  
Finite Element ◽  
Dislocation Density ◽  
Severe Plastic Deformation ◽  
Grain Refinement ◽  
Half Cycle ◽  
Tube Expansion ◽  
Element Method

The microstructure evolution during recently developed severe plastic deformation method named repetitive tube expansion and shrinking of commercially pure AA1050 aluminum tubes has been studied in this paper. The behavior of the material under repetitive tube expansion and shrinking including grain size and dislocation density was simulated using the finite element method. The continuous dynamic recrystallization of AA1050 during severe plastic deformation was considered as the main grain refinement mechanism in micromechanical constitutive model. Also, the flow stress of material in macroscopic scale is related to microstructure quantities. This is in contrast to the previous approaches in finite element method simulations of severe plastic deformation methods where the microstructure parameters such as grain size were not considered at all. The grain size and dislocation density data were obtained during the simulation of the first and second half-cycles of repetitive tube expansion and shrinking, and good agreement with experimental data was observed. The finite element method simulated grain refinement behavior is consistent with the experimentally obtained results, where the rapid decrease of the grain size occurred during the first half-cycle and slowed down from the second half-cycle onwards. Calculations indicated a uniform distribution of grain size and dislocation density along the tube length but a non-uniform distribution along the tube thickness. The distribution characteristics of grain size, dislocation density, hardness, and effective plastic strain were consistent with each other.

Investigations on Microstructure Evolution and Deformation Behavior of Aged and Ultrafine Grained Al-Zn-Mg Alloy Subjected to Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 253-258
Author(s):  
Wei Ping Hu ◽  
Si Yuan Zhang ◽  
Xiao Yu He ◽  
Zhen Yang Liu ◽  
Rolf Berghammer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Microstructure Evolution ◽  
Deformation Behavior ◽  
Deformation Mechanisms ◽  
Mg Alloy ◽  
Ultrafine Grained

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.

Influence of Severe Plastic Deformation on the PLC Effect and Mechanical Properties in Al 5XXX Alloy

2006 ◽  
Vol 114 ◽  
pp. 171-176 ◽  
Author(s):  
Joanna Zdunek ◽  
Pawel Widlicki ◽  
Halina Garbacz ◽  
Jaroslaw Mizera ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
True Strain ◽  
Tensile Tests ◽  
Size Reduction ◽  
Hydrostatic Extrusion ◽  
Stress Strain ◽  
Chatelier Effect

In this work, Al-Mg-Mn-Si alloy (5483) in the as-received and severe plastically deformed states was used. Plastic deformation was carried out by hydrostatic extrusion, and three different true strain values were applied 1.4, 2.8 and 3.8. All specimens were subjected to tensile tests and microhardness measurements. The investigated material revealed an instability during plastic deformation in the form of serration on the stress-strain curves, the so called Portevin-Le Chatelier effect It was shown that grain size reduction effected the character of the instability.

The Influence of Severe Plastic Deformation Process on Structure and Properties of AZ 31 Alloy after Selected Heat Treatment

2018 ◽  
Vol 275 ◽  
pp. 134-146
Author(s):  
Stanislav Rusz ◽  
Ondřej Hilšer ◽  
Stanislav Tylšar ◽  
Lubomír Čížek ◽  
Tomasz Tański ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Structure Refinement ◽  
Hardness Measurement ◽  
Az31 Alloy ◽  
Strength Properties ◽  
Aviation Industry ◽  
Initial State

The technology of structure refinement in materials with the aim of achieving substantial mechanical properties and maintaining the required plasticity level is becoming increasingly useful in industrial practice. Magnesium alloys are very progressive materials for utilization in practice thanks to their high strength-to-weight ratios (tensile strength/density). The presented paper analyses the effect of the input heat treatment of the AZ31 alloy on the change of structure and strength properties through the process of severe plastic deformation (SPD), which finds an increasing utilization, especially in the automotive and aviation industry. For the study of the influence of the SPD process (ECAP method) on the properties of the AZ31 alloy, two types of thermal treatment of the initial state of the structure were selected. The analysis of the structure of the AZ31 alloy was performed in the initial state without heat treatment and subsequently after heat treatment. In the next part, the influence of the number of passes on the strengthening curves was evaluated. Mechanical properties of the AZ31 alloy after ECAP were evaluated by hardness measurement and completed by structure analysis.

Characterization of Microstructure and Mechanical Properties of 6060 Aluminum Alloy Processed by ECAP

2018 ◽  
Vol 275 ◽  
pp. 81-88
Author(s):  
Monika Karoń ◽  
Marcin Adamiak
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Internal Stresses ◽  
Refined Grains ◽  
Angular Pressing ◽  
Heat Treated ◽  
Evolution Of Microstructure

The purpose of this paper is to present the microstructure and mechanical behavior of 6060 aluminum alloy after intense plastic deformation. Equal Channel Angular Pressing (ECAP) was used as a method of severe plastic deformation. Before ECAP part of the samples were heat treated to remove internal stresses in the commercially available aluminium alloy. The evolution of microstructure and tensile strength were tested after 1, 3, 6 and 9 ECAP passes in annealed and non annealed states. It was found that intensely plastically deformed refined grains were present in the tested samples and exhibited increased mechanical properties. Differences were noted between samples without and after heat treatment

Properties of Nanoscaled Multiphase Structures and Non-Equilibrium Solid Solutions Obtained by Severe Plastic Deformation [Abstract + Supplemental Data]

2006 ◽  
Vol 977 ◽  
Author(s):  
Xavier Sauvage ◽  
Xavier Quelennec ◽  
Peter Jessner ◽  
Florian Wetscher ◽  
Reinhard Pippan
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
Solid Solutions ◽  
Atom Probe ◽  
Size Reduction ◽  
Pure Metals ◽  
Pure Cu ◽  
Non Equilibrium

AbstractGrain size reduction induced by severe plastic deformation (SPD) and the resulting mechanical properties have been widely investigated for pure metals but less is known and reported about multi-phase materials. To study the grain size reduction mechanisms in multiphase structure subjected to SPD, two copper based composites (Cu-10%Fe and Cu-43%Cr) were severely deformed by torsion under high pressure. The grain size achieved with these composite materials is much smaller than in pure metals. It is for example in a range of 10 to 20 nm for the Cu-43%Cr composite, e.g. one order of magnitude lower than in pure Cu processed by SPD. Three dimensional atom probe data show also the formation of non equilibrium supersaturated solid solutions. The mechanisms of the deformation induced intermixing are discussed together with its influence on the mechanical properties.

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