Interfacial Phases and Defects Characteristics of Al/Cu-Zn Bimetal Produced via Centrifugal Casting Process

Centrifugal casting process, in both horizontal and vertical mode, is considered as an efficient method to produce bimetallic components. Al/Cu۶۵Zn۳۵ couples were prepared by the vertical centrifugal casting process. In this study, different volume of molten aluminum having melt-to-solid (m/s) volume ratios (VR) of ۱.۵ and ۲.۵, were cast into preheated brass bush rotating at ۸۰۰, ۱۶۰۰, and ۲۰۰۰ (rpm), respectively. The thickness of the interface, which is composed of three different zones, is depended on the rotational speed and the (VR) and was at least ۴۹۰µm (at VR=۱.۵ and ۲۰۰۰ rpm) and at most ۱۴۸۰ µm (at VR=۲.۵ and ۸۰۰ rpm). The results of optical microscopy, energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction analysis showed that the interface layers are composed of Al۲Cu۵Zn۴, Al۳Cu۳Zn, Al۲Cu precipitates dispersed in the matrix and finally α-Al/Al۲Cu anomalous eutectic structure near the aluminum side. Gas pore entrapment and oxide film entrainment defect was detected within the interface next to the aluminum base metal.

Keywords:

Bimetallic Components , Centrifugal Casting , Casting Defects , Interface , Rotational Speed