Functionally Graded in-situ Composites

Introduction:

Functionally graded (FG) materials are a new class of advanced structural materials in which the compostion and the microstructure are intentionally varied from one end to the other end based on the applications

Description:

In the present work, functionally graded aluminium alloy matrix in-situ composites (FE-AMCs) with TiB2 and TiC reinforcements were synthesized using horizontal centrifugal casting process. A commercial Al-Si alloy (A356) and an Al-Cu alloy were used as matrices in the present study. The material parameters (such as matrix and reinforcement type) and process parameters (such as mould temperature, mould speed and melt stirring) were found to influence the gradient in the FG-AMCs. Detailed microstructural analysis of the composites in different processing conditions revealed that the gradients in the reinforcement modify the microstructure and hardness of the Al alloy. The segregated in-situ formed TiB2 and TiC particles change the morphology of Si particles during the solidification of Al-Si alloy. Maximum of 20 vol. % of reinforcement at the surface was achieve by this process in Al-4Cu-TiB2 system. The stirring of the melt before pouring caused the reinforcement particles to segregate at the periphery of the casting, while in the absence of such stirring the particles get segregated at the interior of the casting

Microstructure:

Al-4Cu-TiB2 FG-AMCs

I started to work on this topic from 2008 as a part of my PhD programe with Prof B.S.Murty and Dr V.Subramanya Sarma, for further details of the work please refer to the publication list.