Effect of mould vibration on the mechanical properties of aluminium alloy castings

Abstract

This paper presents the effects of mould vibration on the mechanical properties and microstructure of LM6 and LM26 aluminum alloy castings at different vibration frequencies. The vibration frequencies used during the solidification process were 0, 5 and 9 Hz. The mechanical tests conducted were hardness test, tensile test and fatigue test while microstructure analysis was performed using scanning electron microscope. The experimental results show that the mechanical properties of LM6 and LM26 alloys can be improved by vibration. It was observed that increase in vibration frequency up to 9 Hz led to an increase in ultimate tensile strength from 89.11 to 100.17 MPa for LM6 and from 102.42 to 117.65 MPa for LM26 aluminum alloys. It was also found that hardness and fatigue life improved significantly with the increase in vibration frequency. The microstructural studies reveal finer grains, fragmented microstructure, better distribution and low porosity with the increased application of vibration. This leads to less defects and improved mechanical properties in castings products.