Microstructural Behaviour of Friction Stirred Al/Ni–Fe Hybrid In Situ Composite

Some engineering applications require different surface properties that necessitates development of surface composites that can endure thermal stress, chemical erosion, abrasion etc. Friction stir processing (FSP) is a variant of friction stir welding process. Application in the fabrication of composites via FSP is however subjected to challenges that need to be overcome to extend its application. The challenges attributed to FSP include but are not limited to tunnel defects, cavities and porosity. In this paper, metallurgical characteristic of aluminium surface composite by incorporating 50%Ni 50%Fe as reinforcements into aluminium matrix forming hybrid in situ composites was undertaken. The FSP processing parameters are rotational speed of 1000 rpms, traverse speeds between 70 and 210 mm/min. The powders were homogenised using tubular mixer. The FSP-processed (FSPed) aluminium matrix composites throughput was cross-sectioned in the stir zones and characterised in comparison with aluminium using scanning electron microscopy and X-ray diffraction for microstructural evolution.