INFLUENCE OF VIBRATIONS DURING DIRECTIONAL SOLIDIFICATION ON MICROSTRUCTURE, HARDNESS AND STRENGTH OF Al-Si-GRAPHITE FG COMPOSITE

Abstract

The present work aims to synthesize functionally Graded (FG) composites through directional solidification (DS) in combination with lateral vibrations. Directional solidification is one of the effective processing techniques to synthesize FG composite. Due to the advancements in developing new class of materials, DS has become one of the important processing techniques in order to attain the gradation in properties. To achieve the better gradation of properties in Al-Si alloy, Chill was placed at the bottom of the mold which is subjected to lateral vibrations. FG composites produced showed that better hardness was obtained towards the region where primary Silicon (Si) is precipitated. In contrast diametrical compression strength results revealed that the Si rich region is brittle in nature when compared to the other end of the cast which is ductile in nature. Microstructural study also revealed that gradation in properties has taken place from bottom to top portion due to precipitation of Si.

Keywords

• Functionally graded composite
• vibrations
• Al-18wt%Si
• Diametrical compression test.