Characteristic of interface bimetal aluminum-copper for bimetal bushing produced by centrifugal casting

Bimetallic is a type of metal composite that combines two metals that form a metallurgical bond. The manufacture of bimetallic bushings by centrifugal casting has not been developed much. Recently, there is no recommendation yet for optimum temperature and speed of rotation to produce bimetallic bushings. The research was conducted to determine the rotation of the mold in centrifugal casting so as to produce a well-integrated interface. The materials used for the manufacture of bimetallic bushings are aluminum and copper. Aluminum was melted at a temperature of 750 °C, while copper was melted at 1200 °C. Molten metal was pouring alternately. First, aluminum was poured into the mold, and then after the aluminum temperature reached 400 ºC, copper was poured into the mold to form a bushing aluminum-copper bimetallic. The molten metal was poured into a rotating sand mold with a constant filling speed of about 0.15 kg s-1. The variations of the rotational speed of the mold were 250, 300, and 350 rpm. The result shows that the interface’s width increases as the mold rotation increases during the pouring process. Interface hardness and wear are increased compared to the base metal. Hence, centrifugal casting with 350 rpm is recommended for aluminum-copper bimetal bushing applications.