Study of interface of Al-brass composite fabricated by centrifugal casting

In this research interface of aluminum-brass bimetal composite, fabricated by a vertical centrifugal casting machine, were investigated. At first, brass bushes were preheated at 100-300 °C temperature range and then aluminum melt with 1.5 melt-to-solid volume ratio was cast into cylindrical bush rotating at 800, 1600, and 2000 (rpm), respectively. Obtained samples were studied using optical microscope (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Image J software. Results show that metallurgical joint in this work is probably due to particular dissolving condition, provided by multiple mechanical forces involved and also possible solid diffusion at the end of solidification process. Study of the EDS results show that layers formed at the achieved interface consisted of four discrete layers from the brass side, including Al3Cu5Zn4, Al3Cu3Zn, Al3Cu precipitates scattering in aluminum matrix and finally α-Al/Al3Cu anomalous eutectic structure near the aluminum side.