%0 Journal Article
%T Densification Behaviour in the Fabrication of Al-Fe Metal Matrix Composite Using Powder Metallurgy Route
%A Siddhartha Tiwari
%A Priyanka Rajput
%A Sanjay Srivastava
%J ISRN Metallurgy
%D 2012
%R 10.5402/2012/195654
%X 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¡ãC¨C590¡ãC). 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¡ãC whereas a drop in sintered density is perceived at 590¡ãC. 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. 1. 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. These composites have been widely used for structural, nonstructural, and functional applications in automotive and aerospace industries [1¨C3]. Powder metallurgy (P/M) route is one of the most widely used methods for producing AMCs due to its low processing costs as well as the ease and the accuracy to obtain near net shaped components of complex geometry. The most essential steps of P/M technique are mixing of powders, compaction, and sintering [4¨C6]. Compaction of loose powders under externally applied pressure and sintering of green compacts produced in earlier stage are the main processing parameters, and these parameters affect the density of the final product. Densification behaviour under compaction depends mainly on the applied pressure and yield stress of the powder particles. 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,
%U http://www.hindawi.com/journals/isrn.metallurgy/2012/195654/