Bonding of Interface Bimetal Aluminum-Bronze for Bimetal Bushing Produced by Solid Liquid Method

Abstract

Bimetal is a combination of two dissimilar metals that form a metallurgical bond. The manufacture of bimetallic bushing by centrifugal casting has not been widely developed. There is still no recommendation for optimum temperature used in the manufacture. The aim of this research was to determine the first frozen layer temperature of the aluminum when bronze was poured to produce a well-integrated bond interface. The materials used were aluminum and bronze. Molten metal was pouring into the mold alternately. First, aluminum was poured into the mold. Then, bronze was poured gradually to form a bushing aluminum-bronze bimetallic. The temperature variations of the first frozen layer of aluminum were 27º C, 350º C, 400º C, and 450º C when bronze poured. The molten metal was poured with the filling speed of about 0.2 kg/s into a rotating sand mold. The rotational speed of the mold was 350 rpm. The result shows that the bond interface’s width increases as the first frozen layer aluminum temperature increases. As a result, interface wear and hardness are increased compared to the base metal. Hence, centrifugal casting with the first frozen layer aluminum was 450ºC recommended for aluminum-bronze bimetal bushing applications.

A Review on Casting and Testing of Bimetals

“…There are various process parameters that were used by different researchers in order to observe the variations in the microstructure and bonding of the bimetals at the interface. Some of the process parameters were rotational speed of mold [15], [26], [27], preheat temperature of the mold [17] [26], first frozen layer temperature [9] , pouring speed of melt [11] , superheat temperature of the melt & cooling rate of the mold during casting [27].…”