Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites

Friction stir processing (FSP) has evolved as an important technique in fabrication of metal matrix composites. The surface properties enhancement is obtainable by insertion of desired discontinuous particular reinforcements into base alloy using FSP. Despite having high specific strength, more appl...

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Main Authors: Patil, N.A., Pedapati, S.R., Mamat, O.B., Syah Lubis, A.M.H.
Format: Article
Published: MDPI AG 2019
Online Access:https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078063619&doi=10.3390%2fcoatings9120830&partnerID=40&md5=17b39994309441446013006e57045aa0
http://eprints.utp.edu.my/30256/
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spelling my.utp.eprints.302562022-03-25T06:39:38Z Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites Patil, N.A. Pedapati, S.R. Mamat, O.B. Syah Lubis, A.M.H. Friction stir processing (FSP) has evolved as an important technique in fabrication of metal matrix composites. The surface properties enhancement is obtainable by insertion of desired discontinuous particular reinforcements into base alloy using FSP. Despite having high specific strength, more applications of Al alloys are restricted due to their poor surface properties under various loading conditions. In this study, the main focus is on enhancing the microhardness and wear properties of Al 7075 base alloy by means of uniform dispersion of silicon carbide and graphite (SiC/Gr) nano particles into the base alloy using the FSP technique. The tool rotational speed (w: 500, 1000, 1500 rpm), tool traverse speed (v: 20, 30, 40 mm/min), reinforcement particles hybrid ratio (HR: 60:40, 75:25, 90:10) and volume percentage (vol: 4, 8, 12) are used as independent parameters. The effect of these parameters on microstructure, micro hardness and wear properties of surface composites are studied in detail. For desired wear rate and microhardness as responses, the aforementioned independent parameters are optimized using response surface methodology (RSM). The significance of factors and their interactions for maximizing hardness and minimizing wear rate and coefficient of friction (COF) were determined. Analysis of variance (ANOVA) for responses has been carried out, and the models were found to be significant in all three responses. The minimum wear rate of 0.01194 mg/m was obtained for parameters w 1500 rpm, v 40 mm/min, HR 60:40, vol 4 (Run 10). The maximum micro hardness of 300 HV obtained for parameters w 1000 rpm, v 30 mm/min, HR 75:25, vol 12 (Run 14). The presence and uniform distribution of SiC and Gr into the base alloy was confirmed through field-emission scanning electron microscopy (FESEM) imaging, energy-dispersive X-ray spectroscopy (EDX) and mapping tests. The wear rate and COF decreased significantly due to graphitized mechanically mixed layer developed at the sliding contacts. The microhardness of resultant composites observed to be dependent on effect of the independent parameters on extent of inherent precipitates dissolution and grain size strengthening in the resultant materials. © 2019 by the authors. MDPI AG 2019 Article NonPeerReviewed https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078063619&doi=10.3390%2fcoatings9120830&partnerID=40&md5=17b39994309441446013006e57045aa0 Patil, N.A. and Pedapati, S.R. and Mamat, O.B. and Syah Lubis, A.M.H. (2019) Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites. Coatings, 9 (12). http://eprints.utp.edu.my/30256/
institution Universiti Teknologi Petronas
building UTP Resource Centre
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Teknologi Petronas
content_source UTP Institutional Repository
url_provider http://eprints.utp.edu.my/
description Friction stir processing (FSP) has evolved as an important technique in fabrication of metal matrix composites. The surface properties enhancement is obtainable by insertion of desired discontinuous particular reinforcements into base alloy using FSP. Despite having high specific strength, more applications of Al alloys are restricted due to their poor surface properties under various loading conditions. In this study, the main focus is on enhancing the microhardness and wear properties of Al 7075 base alloy by means of uniform dispersion of silicon carbide and graphite (SiC/Gr) nano particles into the base alloy using the FSP technique. The tool rotational speed (w: 500, 1000, 1500 rpm), tool traverse speed (v: 20, 30, 40 mm/min), reinforcement particles hybrid ratio (HR: 60:40, 75:25, 90:10) and volume percentage (vol: 4, 8, 12) are used as independent parameters. The effect of these parameters on microstructure, micro hardness and wear properties of surface composites are studied in detail. For desired wear rate and microhardness as responses, the aforementioned independent parameters are optimized using response surface methodology (RSM). The significance of factors and their interactions for maximizing hardness and minimizing wear rate and coefficient of friction (COF) were determined. Analysis of variance (ANOVA) for responses has been carried out, and the models were found to be significant in all three responses. The minimum wear rate of 0.01194 mg/m was obtained for parameters w 1500 rpm, v 40 mm/min, HR 60:40, vol 4 (Run 10). The maximum micro hardness of 300 HV obtained for parameters w 1000 rpm, v 30 mm/min, HR 75:25, vol 12 (Run 14). The presence and uniform distribution of SiC and Gr into the base alloy was confirmed through field-emission scanning electron microscopy (FESEM) imaging, energy-dispersive X-ray spectroscopy (EDX) and mapping tests. The wear rate and COF decreased significantly due to graphitized mechanically mixed layer developed at the sliding contacts. The microhardness of resultant composites observed to be dependent on effect of the independent parameters on extent of inherent precipitates dissolution and grain size strengthening in the resultant materials. © 2019 by the authors.
format Article
author Patil, N.A.
Pedapati, S.R.
Mamat, O.B.
Syah Lubis, A.M.H.
spellingShingle Patil, N.A.
Pedapati, S.R.
Mamat, O.B.
Syah Lubis, A.M.H.
Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites
author_facet Patil, N.A.
Pedapati, S.R.
Mamat, O.B.
Syah Lubis, A.M.H.
author_sort Patil, N.A.
title Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites
title_short Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites
title_full Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites
title_fullStr Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites
title_full_unstemmed Optimization of friction stir process parameters for enhancement in surface properties of Al 7075-SiC/Gr hybrid surface composites
title_sort optimization of friction stir process parameters for enhancement in surface properties of al 7075-sic/gr hybrid surface composites
publisher MDPI AG
publishDate 2019
url https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078063619&doi=10.3390%2fcoatings9120830&partnerID=40&md5=17b39994309441446013006e57045aa0
http://eprints.utp.edu.my/30256/
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