Influence of manganese content on the microstructure and properties of AlSi10MnMg(Fe) alloy for die castings

Abstract

This paper was to determine the effect of different manganese addition contents from 0.2 to 1.0 wt.% on the microstructure, HB hardness and selected mechanical properties (UTS; YS; EL) of AlSi10MnMg alloy with increased iron content (about 1.0 wt.%). The proportion of iron in the studied alloy is so high because approx. 50% of the charge came from secondary materials.Chemical composition tests were performed using a Foundry Master Compact 8 emission spectrometer. Static tensile testing at ambient temperature was carried out according to PN-EN ISO 6892-1 on an Instron 3382 using a 20:1 ratio and a constant tensile speed of 5 mm/min-1. Tensile strength (UTS), conventional yield strength (YS), and per cent elongation after rupture of a proportional sample (EL) were determined from this test. Brinell hardness measurement was performed on a Zwick ZHF1, with a loading force of 250 N, with a 5 mm diameter ball for 35 s. Ten measurements were taken, discarding the two outliers, and the arithmetic mean was calculated from the remaining measurements. Metallographic studies were conducted on a MeF-2 Reichert light microscope. X-ray microanalysis studies were carried out on a Hitachi S-3400 scanning microscope coupled to an EDS Voyager X-ray spectrometer equipped with an SE secondary and BSE backscattered electron detector. Chemical composition analysis was performed by energy dispersive X-ray microanalysis (EDS) using a Thermo Noran detector.Increased iron content in aluminium-silicon alloys is a major concern. It causes a significant reduction in the mechanical properties of the materials. This is due, among other things, to the increasing scarcity of primary materials (high cost and environmentally unjustifiable) versus the increasing share of recycled materials. Based on the study, AlSi10MnMg(Fe) alloys obtained under pressure with higher iron content (about 1% wt.), the optimal value of manganese addition is about 0.58% wt.This research has shown that it is possible to use recycled Al-Si materials. The article presents one way to reduce the negative impact of iron addition to aluminium alloys as a result of reusing this type of material.The article presents the effect of manganese addition on the selected aluminium alloy. It was determined that the addition of manganese in the amount of 0.58% wt. causes a significant reduction in the negative effect of iron phases. The article is intended not only for the academic community but also for specialists in the foundry industry.