Paper Title
Functionally Gradient Ti /Al–Cr–Fe Composites Prepared Using Spark Plasma Sintering

Abstract
Five-layer functionally gradient materials (FGM) of Ti and quasicrystal containing Al–Cr–Fe were consolidated using spark plasma sintering (SPS) to improve the wear resistance of Ti components. The phase and microstructure of the layers were characterized by X-ray diffractometer (XRD), scanning electron microscopy equipped with with energy dispersive X-ray spectroscopy (EDX). The microhardness was tested using CSM microhardness tester and the wear resistance was tested by ball-on-disk method. The SPSed FGM exhibits dense microstructure without cracks at the interfaces. A Ti-Al interfacial layer forms between Ti and Al–Cr–Fe particles in the Ti/Al–Cr–Fe mixed layers, suggesting that Ti and Al–Cr–Fe are well-bonded. The microhardness of the Al–Cr–Fe layer (Hv 810) is much higher than that of pure Ti (Hv 318) and the wear rate of Al–Cr–Fe layer is merely 5.2% of that of pure Ti layer. Key words- Composites; Microhardness; Quasicrystal; Spark plasma sintering; Wear resistance