Effect of Mechanical Vibration on the Microstructure and Mechanical Properties of LM6 Reinforced with 6wt.%Cu

Abstract

Eutectic aluminium-silicon alloy (LM6) is widely used in industrial applications due to its excellent casting characteristics and good corrosion resistance. Due to its low strength and hardness, its use is limited in some applications that require high mechanical properties. To enhance the properties of LM6, various methods are used, such as adding alloying elements, heat treatment, or specific casting techniques. The mechanical properties of this alloy are intrinsically linked to its morphological features that occur during the hardening stage. This paper investigates the effect of applying mechanical vibration during solidification on the microstructure and mechanical properties—specifically tensile strength and hardness—of LM6 reinforced with 6 wt.% Cu, followed by heat treatment. During this study, using a sand casting mould under different vibration frequencies to prepare the test samples. Microstructure analysis, and tensile and hardness tests were performed. Experimental results demonstrated that mechanical vibration induces significant grain refinement and a highly homogeneous distribution of the silicon phase within the aluminium matrix. These microstructural modifications notably improve the alloy's tensile strength and hardness compared to non-vibrated samples. Consequently, these findings highlight mechanical vibration as a highly effective processing technique for enhancing the mechanical properties of LM6 alloys reinforced with 6wt.% Cu for high-performance engineering applications.