Synthesis of an Al – Er Addition Alloy and Its Effect on the Structure and Physico-Mechanical Properties of AMg5 Alloy

Abstract

Adoption of structural materials that combine high strength with low specific weight ensures a better energy efficiency of industrial machines and equipment. An aluminium part is almost three times lighter than its steel counterpart. However, it takes high-strength materials to replace critical components that are made of steel. There are high-strength aluminium alloys that contain scandium. However, they only find limited application because of high initial cost of scandium. Erbium works similarly to scandium in terms of strengthening of aluminium alloys, and its cost is 32 times lower. The problem of developing Al – Er alloys is of relevance today. At the same time, more study is necessary to understand the effect of erbium on the overall properties of aluminium alloys. The authors looked at the effect of erbium on the structure, mechanical properties and the fracture pattern of AMg5 alloy (Al – Mg system). Due to the melting temperature difference, erbium was introduced in the aluminium melt as part of an addition alloy produced by an advanced hydriding process. This paper describes a combined study into the obtained addition alloys and as-cast and as-deformed alloys. The authors examined the alloys following a classical pattern of materials research: i.e. composition – structure – properties. Special attention was given to understanding the structure. Thus, conventional optical techniques and scanning electron microscopy were applied, including energy dispersive analysis and electron backscattered diffraction technique. Following a uniaxial tensile test, a positive effect of erbium was observed on the strength of AMg5 alloy in the quasi-static loading region. The obtained results indicate that erbium can potentially be used as a doping element for aluminium alloys. Certain actions are proposed aimed at process optimization to maximize the strengthening effect of erbium in aluminium industry.This research was funded by the Ministry of Education and Science of the Russian Federation under Governmental Assignment no. FSWM-2020-0028.This research was carried out using the facilities of the Tomsk Regional Centre of Shared Knowledge at Tomsk State University and the funding by the Ministry of Science and Higher Education of the Russian Federation received under Contract No. 075–15-2021–693 (No. 13.ЦКП.21.0012) dated 26/07/2021.