Effect of Slope Casting Technique in Integration with Ultrasonic Vibration during Solidification on Structure and Properties of Aluminium Alloy Casting

摘要

Slope casting or cooling slope is a new technology that offers several advantages over liquid processing and solid processing. This process utilises semisolid behaviour as well as reduces macro segregation, porosity and forming forces during shaping process. A cast Al-Cu-Mg alloys have widely used in aircraft, aerospace ships, and boat making, and have good mechanical properties, high strength-to-weight ratio. In this paper investigation was carried out to understand the combined influence of semisolid technique using a cooling slope (CS) and ultrasonic cavitations during solidification on microstructure and mechanical properties of Al-4%Cu-2% Mg Al-4%Cu-2% Mg alloy was alloy was prepared by induction melting. Casting was done in a stainless steel mould into a non-contact type ultrasonic bath via cooling slope. Microstructure and mechanical properties were studied and compared with conventionally cast same alloy in stainless steel mould. Very fine microstructure and better mechanical properties obtained in slope casting in integration with ultrasonic vibration during solidification compared to conventional casting. Improvements in properties are observed due to nondendrite and refined microstructure. The refinement in microstructure is due to high cooling rate. The ultrasonic cavitations help in degassing during solidification.