Fabrication and characterization of Al6063/SiC composites using electromagnetic stir casting process

In this work, metal matrix composites were fabricated using the electromagnetic stir casting process by adding 5 and 10 wt% silicon carbide in Al6063 alloy. Hardness, ultimate tensile strength, and yield strength of the developed Al6063/SiC/5p metal matrix composites have been improved by 17%, 18%, and 37%, respectively, in comparison with Al6063 alloy. Further, an improvement of 25%, 37%, and 71% in hardness, ultimate tensile strength, and yield strength, respectively, have been noted for Al6063/SiC/10p metal matrix composite in comparison with the Al6063 alloy. Results revealed that the hardness and strength of metal matrix composites were increased with silicon carbide addition in Al6063 alloy. The presence of different elements in metal matrix composites was identified by energy-dispersive X-ray spectroscopy and X-ray diffraction techniques. Energy-dispersive X-ray spectroscopy was used for elemental mapping observation of the metal matrix composites. Uniform distribution of reinforcement particles in the matrix with improved mechanical properties of metal matrix composites proved the adequacy of the electromagnetic stir casting process. The presence of facets and dimples in fractographs indicated the mixed mode of fracture. The average percentage porosity presented in Al6063/silicon carbide/5p and Al6063/SiC/10p metal matrix composites was found to be 4.68% and 5.22%, respectively.

Microstructural analysis of Al6063/sic with calcium additives for hardness enhancement

Microstructural Analysis plays an important role in enhancing the mechanical properties of metals and composites. Usually Aluminium Silicon Carbide (Al6063/SiC) alloys are mixed with strontium, sodium and antimony for high durability even though they are toxic and costly. As an alternative calcium is used as an alloying element to improve the mechanical property of Al6063/Sic alloy. In this paper Al6063 is chosen as the matrix material while Sic is used as a reinforcement where calcium powder is added to modify the silicon phase of the composite. Finally, concentration of Silicon carbide is varied from 0 to 150 mg to produce four specimens of Al6063 alloy and it is subjected to microstructure analysis which showed the reduction of grain size and therefore improvement in the hardness from 52.9 HV to 58.4 HV and decrease in the wear loss from 3.97 to 3.27 percentage.