Abstract
Effect of Fe, Ni and Cr addition on the wear behavior of hyper-eutectic Al-Si automotive alloy has been studied. Dry sliding wear tests have been conducted using pin-on-disc wear testing machine under normal loads of 20N and constant sliding speed of 0.64 ms-1. Influence of Fe addition to the base alloy increases the wear rate due to the formation of needle beta intermetallics. Ni addition to the alloy does not impede formation of needle-like intermetallic compounds and has no positive effect on the modification of microstructure. Introducing of Cr to the iron-rich alloy changes the beta intermetallics into the modified alpha phases and therefore reduced the detrimental effect of iron. As a result it recovers the strength and wear properties of the experimental alloy. Wear test surfaces were examined by SEM and have shown that Cr added alloy improves wear resistance through mild and smooth abrasive grooves filled with oxides.
Highlights
Hypereutectic aluminium-silicon alloys are used in applications that require high resistance to wear, corrosion, good mechanical properties, low thermal expansion and reduced density[1,2]
It is due to higher amount of Fe in the alloys led to formation of variety of Fe-rich intermetallic phases in aluminium alloys as Al3Fe, α-Al8Fe2Si, β-Al5FeSi, δ-Al4FeSi2 and γ-Al3FeSi, specially hard β-Al5FeSi phase[23]
Some improvement is observed in Ni added Alloy 3 due to precipitation of Ni intermetallic into the aluminium matrix
Summary
Hypereutectic aluminium-silicon alloys are used in applications that require high resistance to wear, corrosion, good mechanical properties, low thermal expansion and reduced density[1,2]. Their properties are of greatest attention to the automobile industry for the fabrication of fuel-efficient vehicles using light weight components produced from these alloys such as connecting rods, pistons, cylinder liners and engine blocks[3,4,5]. Hyper-eutectic Al-Si alloys can be considered as in situ metal matrix composites, where the primary silicon acts as the reinforcing phase[8,9]. The high latent heat and consequent long solidification time of hypereutectic Al-Si alloys results in excessive growth of primary silicon particles as well as unfavourable shrinkage behavior which adversely affects the use of these alloys[11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
