Microstructure, tensile properties and wear resistance correlations on directionally solidified Al-Sn-(Cu; Si) alloys

Author(s)

Bertelli, Felipe ; Freitas, Emmanuelle S. ; Cheung, Noe ; Arenas, Maria A. ; Conde, Ana ; de Damborenea, Juan ; Garcia, Amauri

• Document type: Journal article
• Source: Journal of Alloys and Compounds; v. 695, p. 3621-3631, FEB 25 2017.
• Web of Science Citations: 19

Abstract

The development of alloys suitable for engine bearings demands not only reducing the amount of wear as well as increasing the load carrying capability due to both engines stop/start systems and sudden rise in load or velocity. Al-Sn based alloys are well-known for having excellent tribological and mechanical properties fulfilling these requirements: Sn is a self-lubricating component and addition of third elements should increase the strength of the Al-rich matrix. The current study focuses on interrelations of microstructure of directionally solidified Al-Sn(Cu; Si) alloys and mechanical/tribological properties. In order to analyze the influence of alloy Sn content on the tribological behavior of these ternary alloys, ball-on-disc wear tests were performed under dry sliding conditions. Correlations between tensile strength, elongation and wear volume and the primary dendritic arm spacing (lambda(1)) have been determined. The worn samples were analyzed by scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) and the wear scar topographies by a confocal profilometer. The analysis of the worn surfaces revealed a change from abrasive to adhesive wear mechanism for Al-Sn-Cu alloys and only adhesive one for Al-Sn-Si alloys. For Al-Sn-Cu alloys, the best wear resistance was observed to be related to coarser microstructures whereas refined microstructures improved the tensile properties, indicating an inverse trend between tensile and tribological properties. The wear resistance of the Al-Sn-Si alloys were shown not to be affected by the size of lambda(1), however the tensile strength is shown to increase significantly with the decrease in lambda(1). (C) 2016 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/50502-5 - Interrelation of thermal and microstructural solidification parameters and corrosion/tribocorrosion behavior of alloys for tribological, biomedical and solder applications
• Grantee: Amauri Garcia
• Support Opportunities: Regular Research Grants
• FAPESP's process: 12/16328-2 - The Correlation between Solidification Microstructures and Mechanical and Tribological Properties of Al-Sn-Cu and Al-Sn-Si Alloys
• Grantee: Felipe Bertelli
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/23396-7 - Effects of solidification MicrostructureParameters of Aluminum-based multicomponent alloys (Al-Mg-Si; Al-Sn-Cu; Al-Zn-Mg) on the resistances to Corrosionand tribocorrosion degradation
• Grantee: Amauri Garcia
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/15478-3 - Interrelation of Solidification Thermal and Microstructural Parameters and Tribocorrosive Behavior of Al-Zn(Mg) e Zn-Mg Alloys
• Grantee: Emmanuelle Sá Freitas Feitosa
• Support Opportunities: Scholarships in Brazil - Post-Doctoral