The Effect of Tin on Microstructure and Properties of the Al-10 wt.% Si Alloy

Abstract

In this paper, the results from studies regarding near-eutectic Al-Si alloys with Sn as an alloying addition are presented. In most Al-Si alloys, tin is regarded as a contaminant; thus, its amount is limited to up to 0.3 wt.%. The few studies that can be found in the literature regarding the behaviour of tin in aluminium alloys suggest the beneficial effect of this element on selected properties. However, these results were obtained for hypereutectic Al-Si alloys or wrought aluminium alloys. In our studies, the influence of tin contents of up to 1.7 wt.% was determined on the AlSi10 alloy. Thermal analysis, measurements of the mechanical properties of the cast and heat-treated alloy, metallographic observations (light microscopy, scanning electron microscopy), and EDS (X-ray energy dispersive spectrometry) measurement allowed us to fully describe the effect of tin on the aluminium alloy. The results of the thermal analysis showed changes in the range of the α-Al solution crystallisation and the α+β eutectic through a decrease in the alloy’s solidification start point and eutectic solidification point. As a result, the elongation of the alloy was more than double in the AlSi10Sn1.7 alloy, with an A5 value of 8.1% and a tensile strength that was above 200 MPa.

The Fatal Defects in Cast Al-Si Alloys Due to Sn Addition

“…When pouring the melt into the mold, the oxide films were rolled into the inner castings and broken into pieces through turbulence [32]. The Sn atoms appeared to segregate in the final solidification areas, causing the further decrease in local matrix solidification temperature [27]. Then, a quantity of liquid with a high Sn solution was trapped in the enclosures, which could not be refilled by other liquids.…”

“…However, a strengthening effect of Sn addition onAl-Si cast alloys was rarely observed. Kozana et al [27] inferred that additions of 0.2-1.7 wt.% Sn to an Al-10Si alloy caused a decrease in the solidification points of α-Al according to their thermodynamic calculations, leading to a drop in melt undercooling and microstructure refinement. As a result, the alloy's ultimate tensile strength was decreased.…”

The Influence of Mn Addition on Corrosion Resistance in Secondary Aluminium Alloy AlSi7Mg0.3 after the Heat Treatment

“…The addition of Mn has been found to have a significant effect on the microstructure and mechanical properties of the alloy, including enhanced corrosion resistance and improved formability. Mn addition can also alter the precipitation kinetics of intermetallic phases and change the type of phases formed in the alloy [6,13,14].…”

Archives of Foundry Engineering

“…Efforts are continuously made to improve their usability thanks to such procedures as the selection and optimization of chemical composition, refining and modification processes, the selection of casting technology and heat treatment parameters [6][7][8][9][10][11][12][13][14]. All these treatments allow obtaining materials with very good mechanical properties, high placticity, and satisfactory hardness,which in turn gives products characterized by good, resistance to the effect of high temperature and corrosive environment.…”