Effect of rotational speeds and heat content on the production of Al- Brass bimetal composite

Composites made of dissimilar metals are designed and used in components subjected to various condition such as serious mechanical force, heat and erosion. Fabrication of Al- brass hollow cylinder, as a composite bimetallic part, is an example. In this work, Al-brass bimetallic hollow cylinders were produced using vertical centrifugal casting device and effective variables were studied. To achieve this, Al melt at 1.5 and 2.5 melt-to-solid volume ratio was cast into 100-400°C preheated cylindrical brass bush rotating at 800 and 1600 revolutions per minute (rpm) respectively and the interface characteristics were investigated. The results of scanning electron microscope (SEM) showed that the achieved interface consisted of four discrete layers from the brass side, including Al2Cu5Zn4, Al3Cu3Zn, Al2Cu precipitates scattering in aluminum matrix and finally α-Al/Al2Cu anomalous eutectic structure near the aluminum side. Micro hardness measurements showed that the hardness of various presented phases decreases from the brass side to the aluminum side.