Experimental investigation on characterization of microwave welded Al6061-Gr-SiC hybrid metal matrix composites

Abstract

In the present work, experimental microwave welding of Al6061-6%Gr-SiC hybrid metal matrix composites (MMC) in bulk form has been carried out. The principle of microwave hybrid heating was applied with domestic microwave having the frequency of 2.45GHz and 900W power. The interface powder Al6061 and susceptor as charcoal powder were used for the welding process. The stir casting process was used to prepare Al6061-6%Gr-SiC hybrid MMCs by varying SiC content by 3%, 6% and 9% and keeping 6% graphite constant by wt%. The composite weld joints were characterized by scanning electron microscope (SEM) equipped with energy dispersive spectrum (EDS) and mechanically through tensile test, Rockwell hardness test and impact test. The microstructure study showed the good metallurgical bonding between the interface and base composites without any visible cracks. The SEM-EDS study revealed the formation of various carbides and inter metallics at the weld interface. The average ultimate tensile strength of the joint was found to be 135MPa with 4.3% elongation. The average Rockwell hardness at the weld joint observed was 61.5HRB. The average impact strength of welded composite was 1.62J/mm2.