Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze casting
In order to produce structural products, Al-Zn-Mg alloys undergo various forming processes. Problems that are usually found in the forming process include peripheral coarse grain (PCG) and hot tearing which decrease mechanical properties and corrosion resistance of the alloys. Addition of microalloy...
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doaj-9efbb1e309c748e2ac2717112b6222b22021-02-02T08:02:50ZengEDP SciencesMATEC Web of Conferences2261-236X2018-01-011530100110.1051/matecconf/201815301001matecconf_icmme2018_01001Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze castingAgustianingrum Maya PutriArandana Nuzulian AkbarWijanarko RislySofyan Bondan TiaraIn order to produce structural products, Al-Zn-Mg alloys undergo various forming processes. Problems that are usually found in the forming process include peripheral coarse grain (PCG) and hot tearing which decrease mechanical properties and corrosion resistance of the alloys. Addition of microalloying element such as chromium (Cr) is an alternative to overcome these problems. The presence of Cr in Al-Zn-Mg alloys supresses the grain growth by preventing excess recrystallization. In this research 0.9 wt. % Cr was added to Al-4.5Zn-1.5Mg alloy and the deformation behaviour as well as subsequent recrystallization was observed. The alloy was fabricated by squeeze casting followed by homogenization at 400 °C for 4 h. The samples were cold rolled for 5, 10, and 20 %. The 20 % deformed samples were then annealed at 300, 400, and 500 °C for 2 h. Material characterization consisted of microstructure analysis using optical microscope and Scanning Electron Microscope (SEM) – Energy Dispersive Spectroscopy (EDS), hardness testing using Micro Vicker methods. The results showed that the deformed grain ratio was 1.6, 2.84, and 2.99 in the 5, 10, and 20 % deformed samples, respectively. The elongated dendrites were effective to increase the hardness of the alloy. Recrystallization was not detected during annealing at 300 and 400 °C, but was observed at 500 °C. Whereas, for the samples without Cr addition, recrystallization occurred at 400 °C. It means that the addition of Cr increased the recrystallization temperature of the alloy. It occured because (Al, Zn)7Cr dispersoids with size less than 1 μm impeded the dislocation motion during annealing, so that recrystallization was retarded. On the other hand (Al, Zn)7Cr dispersoids with size more than 1 μm promoted the formation of new grains around them by Particle Stimulated Nucleation (PSN) mechanism. In this case, the fine (Al, Zn)7Cr dominated so that recrystallization was slower.https://doi.org/10.1051/matecconf/201815301001 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Agustianingrum Maya Putri Arandana Nuzulian Akbar Wijanarko Risly Sofyan Bondan Tiara |
spellingShingle |
Agustianingrum Maya Putri Arandana Nuzulian Akbar Wijanarko Risly Sofyan Bondan Tiara Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze casting MATEC Web of Conferences |
author_facet |
Agustianingrum Maya Putri Arandana Nuzulian Akbar Wijanarko Risly Sofyan Bondan Tiara |
author_sort |
Agustianingrum Maya Putri |
title |
Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze casting |
title_short |
Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze casting |
title_full |
Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze casting |
title_fullStr |
Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze casting |
title_full_unstemmed |
Effect of deformation and annealing temperature on the mechanical properties and microstructure of Al-4.5Zn-1.5Mg-0.9Cr (wt. %) alloy fabricated by squeeze casting |
title_sort |
effect of deformation and annealing temperature on the mechanical properties and microstructure of al-4.5zn-1.5mg-0.9cr (wt. %) alloy fabricated by squeeze casting |
publisher |
EDP Sciences |
series |
MATEC Web of Conferences |
issn |
2261-236X |
publishDate |
2018-01-01 |
description |
In order to produce structural products, Al-Zn-Mg alloys undergo various forming processes. Problems that are usually found in the forming process include peripheral coarse grain (PCG) and hot tearing which decrease mechanical properties and corrosion resistance of the alloys. Addition of microalloying element such as chromium (Cr) is an alternative to overcome these problems. The presence of Cr in Al-Zn-Mg alloys supresses the grain growth by preventing excess recrystallization. In this research 0.9 wt. % Cr was added to Al-4.5Zn-1.5Mg alloy and the deformation behaviour as well as subsequent recrystallization was observed. The alloy was fabricated by squeeze casting followed by homogenization at 400 °C for 4 h. The samples were cold rolled for 5, 10, and 20 %. The 20 % deformed samples were then annealed at 300, 400, and 500 °C for 2 h. Material characterization consisted of microstructure analysis using optical microscope and Scanning Electron Microscope (SEM) – Energy Dispersive Spectroscopy (EDS), hardness testing using Micro Vicker methods. The results showed that the deformed grain ratio was 1.6, 2.84, and 2.99 in the 5, 10, and 20 % deformed samples, respectively. The elongated dendrites were effective to increase the hardness of the alloy. Recrystallization was not detected during annealing at 300 and 400 °C, but was observed at 500 °C. Whereas, for the samples without Cr addition, recrystallization occurred at 400 °C. It means that the addition of Cr increased the recrystallization temperature of the alloy. It occured because (Al, Zn)7Cr dispersoids with size less than 1 μm impeded the dislocation motion during annealing, so that recrystallization was retarded. On the other hand (Al, Zn)7Cr dispersoids with size more than 1 μm promoted the formation of new grains around them by Particle Stimulated Nucleation (PSN) mechanism. In this case, the fine (Al, Zn)7Cr dominated so that recrystallization was slower. |
url |
https://doi.org/10.1051/matecconf/201815301001 |
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