Solid-State Recycling of Aluminum Alloy (AA-6061) Chips via Hot Extrusion Followed by Equal Channel Angular Pressing (ECAP)

Solid state recycling through hot extrusion is a promising technique to recycle machining chips without remelting. Furthermore, equal channel angular pressing (ECAP) technique coupled with the extruded recycled billet is introduced to enhance the mechanical properties of recycled samples. In this paper, the surface roughness of solid state recycled aluminum alloy 6061 turning chips was investigated. Aluminum chips were cold compacted and hot extruded under an extrusion ratio (ER) of 5.2 at an extrusion temperature (ET) of 425°C. In order to improve the properties of the extruded samples, they were subjected to ECAP up to three passes at room temperature using an ECAP die with a channel die angle(Φ)of 90°. Surface roughness (RaandRz) of the processed recycled billets machined by turning was investigated. Box-Behnken experimental design was used to investigate the effect of three machining parameters (cutting speed, feed rate, and depth of cut) on the surface roughness of the machined specimens for four materials conditions, namely, extruded billet and postextrusion ECAP processed billets to one, two, and three passes. Quadratic models were developed to relate the machining parameters to surface roughness, and a multiobjective optimization scheme was conducted to maximize material removal rate while maintaining the roughness below a preset practical value.

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Artificial aging time influencing the crack propagation behavior of the aluminum alloy 6060 processed by equal channel angular pressing

Materials Science and Engineering A ◽

10.1016/j.msea.2021.141039 ◽

2021 ◽

Vol 811 ◽

pp. 141039

Author(s):

Lisa-Marie Rymer ◽

Lisa Winter ◽

Kristin Hockauf ◽

Thomas Lampke

Keyword(s):

Aluminum Alloy ◽

Crack Propagation ◽

Aging Time ◽

Equal Channel Angular Pressing ◽

Artificial Aging ◽

Angular Pressing ◽

Propagation Behavior ◽

Crack Propagation Behavior

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Effect of equal channel angular pressing on the microstructure of a semisolid aluminum alloy

Materials Science and Engineering A ◽

10.1016/j.msea.2007.04.047 ◽

2008 ◽

Vol 475 (1-2) ◽

pp. 224-228 ◽

Cited By ~ 17

Author(s):

S. Hossein Nedjad ◽

H. Meidani ◽

M. Nili Ahmadabadi

Keyword(s):

Aluminum Alloy ◽

Equal Channel Angular Pressing ◽

Angular Pressing

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Microstructure Evolution and Coarsening Mechanism of 7075 Semi-Solid Aluminum Alloy Pre-Deformed by ECAP Method

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.256.294 ◽

2016 ◽

Vol 256 ◽

pp. 294-300 ◽

Cited By ~ 4

Author(s):

Jin Long Fu ◽

Yu Wei Wang ◽

Kai Kun Wang ◽

Xiao Wei Li

Keyword(s):

Aluminum Alloy ◽

Solid State ◽

Ostwald Ripening ◽

Liquid Fraction ◽

Isothermal Holding ◽

Angular Pressing ◽

Average Grain Size ◽

Semi Solid ◽

Equiaxed Grains ◽

Kinetics Of

To investigate the influence of refined grains on the microstructure of 7075 aluminum alloy in semi-solid state, a new strain induced melting activation (SIMA) method was put forward containing two main stages: pre-deformation with equal channel angular pressing (ECAP) method and isothermally holding in the semi-solid temperature range. The breaking up and growth mechanisms of the grains and kinetics of equiaxed grains coarsening during the semi-solid holding were investigated. The results showed that the average grain size after ECAP extrusion decreased significantly, e.g., microstructure with average globular diameter less than 5μm was achieved after four-pass ECAP extrusion. Obvious grain coarsening had been found during isothermal holding in the semi-solid state and the roundness of the grains increased with the increasing holding time. The proper microstructure of 66.8μm in diameter and 1.22 in shape factor was obtained under proper soaking condition (at 590°C for 15 min). Two coarsening mechanisms, namely, coalescence in lower liquid fraction and Ostwald ripening in higher liquid fraction contributed to the grain growth process.

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Influence of aging on mechanical properties of equal channel angular pressed aluminum alloy 7075

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405415612370 ◽

2015 ◽

Vol 231 (10) ◽

pp. 1803-1811 ◽

Cited By ~ 5

Author(s):

Seyed Mahmoud Ghalehbandi ◽

Alireza Fallahi Arezoodar ◽

Hossein Hosseini-Toudeshky

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Equal Channel Angular Pressing ◽

Room Temperature ◽

Solution Treatment ◽

Aging Treatment ◽

Subsequent Aging ◽

Good Ductility ◽

Angular Pressing ◽

Aluminum Alloy 7075

Effect of aging treatment on mechanical properties of an age-hardenable aluminum alloy after equal channel angular pressing at room temperature has been investigated using hardness, stress–strain behavior and surface fractography. Aluminum alloy 7075 was pressed after solution treatment. Yield stress, ultimate stress and hardness of pressed samples have increased significantly compared with those of coarse grain, but the elongation to failure has decreased. Also the pressed specimens were subjected to aging treatment at room temperature and temperatures of 80 °C, 100 °C, 120 °C and 140 °C to obtain the optimized strength and ductility. The results indicated that post–equal channel angular pressing aging at 80 °C has resulted in the maximum strength, and natural aging has resulted in good ductility and acceptable strength. It confirmed the fact that there is a potential in obtaining high strength and good ductility in age-hardenable alloys employing severe plastic deformation and subsequent aging.

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Microstructural Characterization of an Al-Mg-Si Aluminum Alloy Processed by Equal Channel Angular Pressing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.745-746.303 ◽

2013 ◽

Vol 745-746 ◽

pp. 303-308

Author(s):

Zhen Zhang ◽

Man Ping Liu ◽

Ying Da Yu ◽

Pål C. Skaret ◽

Hans Jørgen Roven

Keyword(s):

Aluminum Alloy ◽

Electron Microscope ◽

High Resolution ◽

Dislocation Density ◽

Equal Channel Angular Pressing ◽

Transmission Electron Microscope ◽

Microstructural Characterization ◽

Dark Field ◽

Angular Pressing ◽

Transmission Electron

In the present work, a peak-aged 6061 Al-Mg-Si aluminum alloy was subjected to equal channel angular pressing (ECAP) at 110 °C. The microstructure of the sample was characterized by high-resolution transmission electron microscope and weak-beam dark-field method. It was shown that the dislocation density in some local areas is much lower than the average dislocation density expected in the usual alloys processed by severe plastic deformation. High-resolution transmission electron microscope observations indicated that many full dislocations were dissociated into partial dislocations connected by stacking faults. In addition, a Z-shaped defect (i.e., a type of dislocation locks) probably formed by the reactions of the partials in different {111} planes was first observed in the ECAPed alloy. Furthermore, the precipitation behavior and sequence in the present ECAPed sample were identified by high-resolution transmission electron microscopy.

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