Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze Casting

Aluminium alloys are developed as airplane body due to their lighter weight compared to steel and good formability. Aluminium 7XXX series with Zn and Mg alloying elements is commonly used because its mechanical properties can be improved through a deformation process. A deformation process such as c...

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Main Authors: Rachman Kurnia, Bondan Tiara Sofyan
Format: Article
Language:English
Published: Universitas Indonesia 2017-12-01
Series:International Journal of Technology
Subjects:
Online Access:http://ijtech.eng.ui.ac.id/article/view/680
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author Rachman Kurnia
Bondan Tiara Sofyan
author_facet Rachman Kurnia
Bondan Tiara Sofyan
author_sort Rachman Kurnia
collection DOAJ
description Aluminium alloys are developed as airplane body due to their lighter weight compared to steel and good formability. Aluminium 7XXX series with Zn and Mg alloying elements is commonly used because its mechanical properties can be improved through a deformation process. A deformation process such as cold rolling may increase the hardness of an alloy through strain hardening. An annealing process following the deformation process will recover ductility through stress relief, recrystallization, and grain growth mechanisms. This research aimed to discover the effect of cold rolling and annealing temperature on the recrystallization and mechanical properties of Al-4.7Zn-1.8Mg (wt. %) alloy. The alloy was produced by a squeeze casting process. Homogenization was conducted at 400oC for 4 hours followed by cold rolling with degrees of deformation of 5%, 10%, and 20%. The samples with 20% deformation were then annealed at 300oC, 400oC, and 500oC for 2 h. The Vickers hardness test was performed on the cold-rolled and annealed samples to reveal the strain hardening effect and subsequent recrystallization process. The microstructure was observed using an optical microscope and a Scanning Electron Microscope (SEM). The results showed that the higher the deformation, the more elongated the grains. Deformation of 5, 10 and 20% led to grain shape ratios of 2.19, 3.19 and 4.59, respectively and increase in the hardness of the alloy from 69.5 VHN to 95.3, 100.1 and 105.4 VHN, respectively. Slip bands and cross slips were found only in the 20% deformed samples. The annealing process resulted in recovery at 300oC, followed by recrystallization at 400oC (dgrain ~290 ?m) and grain growth at 500oC (dgrain ~434 ?m). Annealing temperatures of 300oC, 400oC and 500oC decreased the hardness of the alloy from 105.4 VHN to 71.5, 96.8 and 95.3 VHN, respectively.
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spelling doaj.art-d0fd5d5d5f4b4991a968249a1dd3b1772023-01-02T22:40:00ZengUniversitas IndonesiaInternational Journal of Technology2086-96142087-21002017-12-01871329133510.14716/ijtech.v8i7.680680Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze CastingRachman Kurnia0Bondan Tiara Sofyan1- Department of Metallurgy and Materials Engineering, Universitas Indonesia<br/>-- Department of Metallurgy and Materials Engineering, Universitas IndonesiaAluminium alloys are developed as airplane body due to their lighter weight compared to steel and good formability. Aluminium 7XXX series with Zn and Mg alloying elements is commonly used because its mechanical properties can be improved through a deformation process. A deformation process such as cold rolling may increase the hardness of an alloy through strain hardening. An annealing process following the deformation process will recover ductility through stress relief, recrystallization, and grain growth mechanisms. This research aimed to discover the effect of cold rolling and annealing temperature on the recrystallization and mechanical properties of Al-4.7Zn-1.8Mg (wt. %) alloy. The alloy was produced by a squeeze casting process. Homogenization was conducted at 400oC for 4 hours followed by cold rolling with degrees of deformation of 5%, 10%, and 20%. The samples with 20% deformation were then annealed at 300oC, 400oC, and 500oC for 2 h. The Vickers hardness test was performed on the cold-rolled and annealed samples to reveal the strain hardening effect and subsequent recrystallization process. The microstructure was observed using an optical microscope and a Scanning Electron Microscope (SEM). The results showed that the higher the deformation, the more elongated the grains. Deformation of 5, 10 and 20% led to grain shape ratios of 2.19, 3.19 and 4.59, respectively and increase in the hardness of the alloy from 69.5 VHN to 95.3, 100.1 and 105.4 VHN, respectively. Slip bands and cross slips were found only in the 20% deformed samples. The annealing process resulted in recovery at 300oC, followed by recrystallization at 400oC (dgrain ~290 ?m) and grain growth at 500oC (dgrain ~434 ?m). Annealing temperatures of 300oC, 400oC and 500oC decreased the hardness of the alloy from 105.4 VHN to 71.5, 96.8 and 95.3 VHN, respectively.http://ijtech.eng.ui.ac.id/article/view/680Al-Zn-Mg alloyAnnealingCold rollingGrain growthRecrystallization
spellingShingle Rachman Kurnia
Bondan Tiara Sofyan
Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze Casting
International Journal of Technology
Al-Zn-Mg alloy
Annealing
Cold rolling
Grain growth
Recrystallization
title Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze Casting
title_full Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze Casting
title_fullStr Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze Casting
title_full_unstemmed Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze Casting
title_short Effect of Cold Rolling and Annealing Temperature on the Recrystallization and Mechanical Properties of Al-4.7Zn-1.8Mg (wt. %) Alloy Fabricated by Squeeze Casting
title_sort effect of cold rolling and annealing temperature on the recrystallization and mechanical properties of al 4 7zn 1 8mg wt alloy fabricated by squeeze casting
topic Al-Zn-Mg alloy
Annealing
Cold rolling
Grain growth
Recrystallization
url http://ijtech.eng.ui.ac.id/article/view/680
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