Understanding the effect of basalt fibres on the structure and physical and mechanical properties of aluminium alloy AK9

Abstract

This paper looks at a composite material based on Al – Si alloy of grade AК9 that was produced by mechanical stirring and reinforced with 1 and 2 wt % of basalt fibres. The paper describes the results of a study that looked at the structure and phase composition of the basalt fibres introduced. It is shown that heat treating basalt fibres at the temperatures of up to 600 oC does not change their phase composition. The authors examine the microstructures of the initial cast alloy AK9 and the alloy reinforced with basalt fibres; look at the relationship between the structure obtained after introduction of basalt fibres and the physical and mechanical properties of the alloy; carried out a fractography study of the fracture surface in reinforced alloy specimens following a series of tensile tests. The authors analyzed how reinforcing effect is achieved when basalt fibres are introduced in the aluminium alloy AK9. The experimental data indicate that the introduction of basalt fibres in the aluminium matrix significantly enhances the mechanical performance of the alloy compared with the initial alloy AK9. Thus, the tensile strength and ultimate strength rise by 40 to 55 % compared with the initial alloy, whereas the hardness rises by 20 to 35 % depending on the weight fraction of basalt fibres in the alloy.This research was funded by the Ministry of Education and Science of the Russian Federation under Governmental Assignment No. FSWM-2020-0028. The studies (optical and electron microscopy, tensile tests, hardness and microhardness tests, study of phase composition) were carried out using the facilities of the Tomsk Regional Shared Knowledge Centre, a part of the National Research Tomsk State University. Support for the Centre is provided by the Ministry of Higher Education and Science of the Russian Federation under Grant No. 075-15-2021-693 (No. 13.ЦКП.21.0012).