Production of Al-6Si-0.3Cu-0.3X (X=Be, Sc, Sb and Ti) alloy trough melt-spinning and spark plasma sintering techniques and investigation of their mechanical properties

In this study, Al- 6 wt. % Si- 0.3 wt. % Cu- 0.3 wt. % X (X= Be, Sb, Sc and Ti) alloy was first produced as ingot by induction melting method and as ribbon by melt spinning method. Melt-spun ribbons were consolidated by spark plasma sintering (SPS) and cold compaction methods. While the ribbons were consolidated directly in the SPS method, the ribbons were firstly brought into powder form by ball milling in the cold compaction method. The crystal structure, microstructure and mechanical properties of the produced alloys were evaluated in terms of production method and additive elements. From the X-ray diffraction analysis, no impurity peaks were found in the ingot alloys, except for the diffraction peaks of Al and Si. In ribbon alloys, the increase in Si peak width was interpreted as nano-crystal structure formation. Optical microscope and scanning electron microscope images showed that α-Al and eutectic Si structure were formed in the ingot alloys. While the acicular Si morphology was evident in the undoped alloy, it was observed that Si turned into a fine fibrous structure in Be, Sb and Ti doped alloys. Ribbon alloys exhibited a network like microstructure. In the consolidated alloys, Si was coarsened but exhibited a more homogeneous distribution in the microstructure. From Vicker's hardness analysis, it was seen that the SPS compacted ribbons have a hardness value between ingot alloys and ribbon alloys. Also, Sb doped alloy had the highest hardness value compared to the other doped alloys.