Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) Technology

In addition to impurities in recycled aluminum alloys, non-metallic inclusions are a significant factor that deteriorates the material’s castability and final mechanical properties. This, therefore, restricts the ability to transition from a primary to secondary aluminum alloy. In this study, the cl...

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Main Authors: Zhichao Niu, Zhongping Que, Jayesh B. Patel, Zhongyun Fan
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Crystals
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Online Access:https://www.mdpi.com/2073-4352/14/12/1044
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author Zhichao Niu
Zhongping Que
Jayesh B. Patel
Zhongyun Fan
author_facet Zhichao Niu
Zhongping Que
Jayesh B. Patel
Zhongyun Fan
author_sort Zhichao Niu
collection DOAJ
description In addition to impurities in recycled aluminum alloys, non-metallic inclusions are a significant factor that deteriorates the material’s castability and final mechanical properties. This, therefore, restricts the ability to transition from a primary to secondary aluminum alloy. In this study, the cleanliness of the recycled A357 alloy was evaluated through non-metallic inclusions’ characterization, hydrogen content measurement, fluidity test, and casting defects identification. The non-metallic inclusions generated during the recycling process of A357 alloy were collected by the pressurized melt filtration technique. All of the inclusion types collected during filtration were examined and identified by analytical scanning electron microscopy (SEM). Extra additions of up to 2 wt.% swarf in these secondary A357 alloys were designed to simulate highly contaminated alloys. Different to the conventional melt cleaning technologies that mainly focus on complete removal of inclusions, this study developed a novel approach that combines the removal of easily removeable inclusions while preserving well-dispersed inclusions that do not adversely affect the mechanical properties. This study demonstrates that high shear melt conditioning (HSMC) technology can achieve well-dispersed small non-metallic inclusions, low hydrogen content, improved fluidity, and fewer casting defects. As a result, the melt quality of the recycled A357 alloys has achieved a quality comparable to that of primary A357 alloy.
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spelling doaj-art-5bfe892183444e53957d12e1f2905d1d2025-08-20T02:00:37ZengMDPI AGCrystals2073-43522024-11-011412104410.3390/cryst14121044Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) TechnologyZhichao Niu0Zhongping Que1Jayesh B. Patel2Zhongyun Fan3Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University London, Uxbridge UB8 3PH, UKBrunel Centre for Advanced Solidification Technology (BCAST), Brunel University London, Uxbridge UB8 3PH, UKBrunel Centre for Advanced Solidification Technology (BCAST), Brunel University London, Uxbridge UB8 3PH, UKBrunel Centre for Advanced Solidification Technology (BCAST), Brunel University London, Uxbridge UB8 3PH, UKIn addition to impurities in recycled aluminum alloys, non-metallic inclusions are a significant factor that deteriorates the material’s castability and final mechanical properties. This, therefore, restricts the ability to transition from a primary to secondary aluminum alloy. In this study, the cleanliness of the recycled A357 alloy was evaluated through non-metallic inclusions’ characterization, hydrogen content measurement, fluidity test, and casting defects identification. The non-metallic inclusions generated during the recycling process of A357 alloy were collected by the pressurized melt filtration technique. All of the inclusion types collected during filtration were examined and identified by analytical scanning electron microscopy (SEM). Extra additions of up to 2 wt.% swarf in these secondary A357 alloys were designed to simulate highly contaminated alloys. Different to the conventional melt cleaning technologies that mainly focus on complete removal of inclusions, this study developed a novel approach that combines the removal of easily removeable inclusions while preserving well-dispersed inclusions that do not adversely affect the mechanical properties. This study demonstrates that high shear melt conditioning (HSMC) technology can achieve well-dispersed small non-metallic inclusions, low hydrogen content, improved fluidity, and fewer casting defects. As a result, the melt quality of the recycled A357 alloys has achieved a quality comparable to that of primary A357 alloy.https://www.mdpi.com/2073-4352/14/12/1044recycled A357 alloynon-metallic inclusionshigh shear melt conditioning (HSMC)material castabilitymechanical properties
spellingShingle Zhichao Niu
Zhongping Que
Jayesh B. Patel
Zhongyun Fan
Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) Technology
Crystals
recycled A357 alloy
non-metallic inclusions
high shear melt conditioning (HSMC)
material castability
mechanical properties
title Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) Technology
title_full Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) Technology
title_fullStr Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) Technology
title_full_unstemmed Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) Technology
title_short Assessment and Improvement of Melt Quality of Recycled Secondary A357 Alloy by Application of the High Shear Melt Conditioning (HSMC) Technology
title_sort assessment and improvement of melt quality of recycled secondary a357 alloy by application of the high shear melt conditioning hsmc technology
topic recycled A357 alloy
non-metallic inclusions
high shear melt conditioning (HSMC)
material castability
mechanical properties
url https://www.mdpi.com/2073-4352/14/12/1044
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