Densification Behaviour in the Fabrication of Al-Fe Metal Matrix Composite Using Powder Metallurgy Route

Siddhartha Tiwari,Priyanka Rajput,Sanjay Srivastava

doi:10.5402/2012/195654

Abstract

Densification behaviour of the powder particles in two- and/or multicomponent system is unpredictable. The present work deals with the densification behaviour of Al-Fe powder particles during compaction and sintering in order to fabricate the Al-Fe metal matrix composites by powder metallurgy route. Green compacts of Al-6.23 wt.% Fe powder particles were fabricated under varying compaction pressures, and these fabricated green compacts were sintered over a series of temperatures (430°C–590°C). The sintered products have been characterised with the help of X-ray diffraction (XRD) and scanning electron microscope attached with energy dispersive spectroscopy (EDS). It has been found that the green density of the compacts increases with increase in compaction pressure. The rate of change in green density is found to be lower at higher compaction pressures. Sintered density increases with increasing sintering temperature up to 550°C whereas a drop in sintered density is perceived at 590°C. This decrease in sintered density is considered to occur due to swelling which has been explained on the basis of the Kirkendall effect. The XRD and EDS analyses of sintered products indicated the presence of Al and Fe particles with the trace amount of intermetallics.

Highlights

Aluminium matrix composites (AMCs) are one of the most demanding engineering materials in the category of metal matrix composites (MMCs) due to combination of their light weight and excellent mechanical and tribological properties
Green compacts of Al-6.23 wt.% Fe powder particles were fabricated under varying compaction pressures, and these fabricated green compacts were sintered over a series of temperatures (430◦C–590◦C)
In order to achieve maximum sintered density in the fabrication of Al-rich Al-Fe (Al-6.23 wt.% Fe) metal matrix composites, optimum sintering temperature is found to be 550◦C

Summary

Introduction

Aluminium matrix composites (AMCs) are one of the most demanding engineering materials in the category of metal matrix composites (MMCs) due to combination of their light weight and excellent mechanical and tribological properties. One of the important processing steps in P/M route is sintering, which is used to produce density-controlled materials and components from metal and/or ceramic powders by applying thermal energy. It can be divided into two categories: solid-state sintering and liquid-state sintering, below and above the melting temperature respectively [7]. In the present investigation, an attempt has been made to examine the compaction and sintering behaviour of Al-rich Al-Fe binary phase system This experimental study deals with the densification behaviour of mixture of Al-6.23 wt.% Fe powders under compaction and sintering to produce Al-Fe metal matrix composite by P/M route. The swelling behaviour at higher sintering temperature is discussed

Experimental

Effect of Compaction Pressure

Effect of Sintering Temperature

Conclusions