Recycling of AZ91 Mg alloy through consolidation of machined chips by extrusion and ECAP

Ying, Tiejin; Zheng, M.Y.; Hu, X.S.; Wu, Kun

doi:10.1016/s1003-6326(10)60547-x

Cited by 53 publications

(19 citation statements)

References 18 publications

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“…In addition, recycling processes based on other SPD methods such as cyclic extrusion compression (CEC) [16], equal channel angular pressing (ECAP) [17][18][19], high-pressure torsion (HPT) [20] or compressive torsion [21], and combined use of forward extrusion and ECAP [22,23] have also been reported. Recently, another study [24] aimed at producing a composite material including nano-particles from machining chips via hot extrusion, and a new method was proposed to produce clad plates from iron chips by using hot rolling [25].…”

Section: Introductionmentioning

confidence: 99%

Solid-state recycling of aluminium alloy swarf into c-channel by hot extrusion

Chiba

Yoshimura

2015

Journal of Manufacturing Processes

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Section: Introductionmentioning

confidence: 99%

Solid-state recycling of aluminium alloy swarf into c-channel by hot extrusion

Chiba

Yoshimura

2015

Journal of Manufacturing Processes

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“…There were only a few papers where combination of extrusion and ECAP process was investigated. Ying et al [18] investigated solid state recycling of AZ91 Mg alloy utilizing combination of the hot extrusion and afterwards one ECAP pass on 300 • C. After ECAP on elevated temperatures, crystal grains were refined inside recycled specimens. Furthermore, interfaces of the chips disappear after extrusion and after ECAP, which indicates the improvement of the bonding between chips [18].…”

mentioning

confidence: 99%

“…Ying et al [18] investigated solid state recycling of AZ91 Mg alloy utilizing combination of the hot extrusion and afterwards one ECAP pass on 300 • C. After ECAP on elevated temperatures, crystal grains were refined inside recycled specimens. Furthermore, interfaces of the chips disappear after extrusion and after ECAP, which indicates the improvement of the bonding between chips [18]. Krolo et al [19] utilized a combination of the direct hot extrusion and ECAP at different temperatures to investigate the influence of SSR process parameters on recycled samples microhardness and electrical conductivity.…”

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confidence: 99%

Statistical Analysis of the Combined ECAP and Heat Treatment for Recycling Aluminum Chips Without Remelting

Krolo

Lela

Dumanić

et al. 2019

Metals

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The main aim of this paper is to present an environmentally friendly method for aluminum recycling. Development of new recycling technologies in order to increase scrap reuse potential and CO 2 emission savings are of the main importance for aluminum circular economy. In this paper, aluminum chips waste was recycled without any remelting phase in order to increase energy and material savings. The presented process is usually called solid state recycling or direct recycling. Solid state recycling process consists of chips cleaning, cold pre-compaction and hot direct extrusion followed by a combination of equal channel angular pressing (ECAP) and heat treatment. Influence of holding time during solid solution treatment and both artificial aging time and temperature on mechanical properties of the recycled EN AW 6082 aluminum chips were investigated. A comprehensive number of the experiments were performed utilizing design of experiments approach and response surface methodology. Regression models were developed for describe the influence of heat treatment parameters for presented solid state recycling process on mechanical properties of the recycled samples. Utilizing novel procedure high quality recycled samples were obtained with mechanical properties comparable with commercially produced EN AW 6082 aluminum alloy in T6 temper condition. Metallographic analysis of the recycled samples was also performed.In order to reduce the negative effect on the environment, various authors recognized solid state recycling (SSR) as a possible alternative to the conventional aluminum recycling process [4][5][6][7][8][9]. When SSR is employed, material losses are much smaller because the remelting phase is completely avoided. Aluminum is a highly reactive material and it has a tendency to form aluminum oxide on its surface. This is even more pronounced for lightweight aluminum scrap due to its high surface to mass ratio. During the remelting process this oxide is floating on the melt surface mixed with dross. Therefore, aluminum lightweight scrap (chips, foils, and sheet skeletons) is problematic when conventional recycling technology is used because up to 20% of the aluminum can be lost due to the mixing with dross and burning [9]. According to previous research papers concerned with SSR process, it is possible for material yield to be over 90% when this type of recycling is employed, while energy consumption can be only 10% compared to conventional recycling process that uses remelting [6][7][8]. Furthermore, manufacturing profiles from solid state bonded chips gives a 96% saving in CO 2 emission compared to production from billets made by conventional recycling of aluminum manufacturing waste [8]. In order to produce SSR samples with appropriate quality, the combination of the high temperature, normal stress, shear stress, and plastic deformation should be achieved [6,7]. Therefore, the most used process for SSR is direct hot extrusion, but lately severe plastic deformation (SPD) processes opened new possibilities [10]. SPD i...

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“…To a continuous process forward fit is possible to implement a number of methods such as equal channel angular pressing (ECAP) [7][8][9][10][11][12][13][14], twist extrusion (TE) [15][16][17], or friction stir processing called as KOBO [18,19]. Authors [6,20] achieved superior bonding quality of chip-based extrudates byintegrated aluminum extrusion and equal channel angular pressing (iECAP) at the low extrusion ratio of ~8.7: first Well properties are achieved by extruding through feeder porthole die, with two or four feeder [4][5][6]21]. Authors [4] reported that for the welding of the chips two criterions must be fulfilled.…”

Section: Introductionmentioning

confidence: 99%

Various Possibilities of the Hot Extrusion in Aluminum Chips Processing

Kočiško

Bidulský

Dragošek

et al. 2014

Acta Metall Slovaca

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This article deals with the analysis and comparison of the conditions for solid state welding during extrusions by means of numerical simulation. Numerical simulations made on four different matrices, such as square die without integrated extrusion and equal channel angular pressing (iECAP), porthole die whit one and four square profile. Maximum volume and distribution of effective strain, strain rate and shear stress was analyzing. The results show that during cold molding of chips there is mutual deformations of chips, which are rearranged and mechanically crimped. In the first phase of pressing occurs complete elimination of porosity. The square die with iECAP was extrusion force is 30% higher than porthole die. Maximum effective strain was calculated for the porthole die whit four square profile.

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Recycling of AZ91 Mg alloy through consolidation of machined chips by extrusion and ECAP

Cited by 53 publications

References 18 publications

Solid-state recycling of aluminium alloy swarf into c-channel by hot extrusion

Solid-state recycling of aluminium alloy swarf into c-channel by hot extrusion

Statistical Analysis of the Combined ECAP and Heat Treatment for Recycling Aluminum Chips Without Remelting

Various Possibilities of the Hot Extrusion in Aluminum Chips Processing

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