IMPACT OF MECHANICAL VIBRATION ON GRAVITY DIE CASTING OF ALUMINIUM ALLOYS: AN IN-DEPTH ANALYSIS

Abstract

An aluminum alloy casting, widely employed in industrial engineering, offers the ability to fabricate products with intricate shapes at lower superheat through a straightforward processing run. Given the prevalent use of aluminum alloy, there is a growing need to enhance its mechanical properties and grain structure. This review delves into the impact of mechanical vibration on the mechanical properties and microstructure of aluminum alloy during gravity die casting.

The study specifically investigates gravity die castings of AC4C aluminum alloy (AlSi7Mg) under mechanical vibration ranging from 0 to 120 Hz, utilizing an actual casting machine. During the casting process, a portion of the mold, referred to as the vibrating mold, is oscillated by a vibrator. Mechanical vibration is applied before pouring and ceased 40 seconds after pouring. Columnar rod specimens measuring 25 mm in diameter and 210 mm in length were cast to examine the effects of mechanical vibration on grain size, internal defects, and mechanical properties.

The imposition of mechanical vibration resulted in a notable decrease in the grain size of columnar rod specimens, reducing from 1800 µm (0 Hz) to 750 µm (100 Hz). The internal defects of the specimens decreased when subjected to mechanical vibration with a frequency of 70 Hz or less. However, vibrations at 80 Hz or higher led to an increase in internal defects. Consequently, specimens cast with a vibration frequency of 70 Hz exhibited higher ultimate tensile strength (UTS) compared to those cast under different vibration conditions