Ultrasonic Cast Bonding of Sheet Steel to Aluminum in a Metal Mold

Conventional cast-on methods are incapable of metallurgically bonding a steel plate to an external surface of a small aluminum casting in a metal mold. We, for the first time, demonstrated that such kind of bonding could be achieved using an ultrasound-assisted cast-on method termed ultrasonic cast bonding. Castings were made using ultrasonic cast bonding under various processing parameters including pouring temperature of the molten alloy, type of the steel plate, power of ultrasonic vibrations, and coupling method of ultrasonic vibration to the steel plate. The force required to separate the steel plate from the casting was measured to evaluate factors affecting the bonding quality of the bimetal. Microstructural analysis was performed to reveal the nature of the bonding. Basic conditions required for obtaining metallurgical bonding between steel and aluminum were discussed.