An aluminum 6061 (Al6061) metal matrix composite (MMC) reinforced with silicon carbide was prepared by stir casting. Specimens of the required dimensions were welded using the tungsten inert gas (TIG) method. ER5356 (Al-5%Mg) was chosen as the appropriate filler material for TIG welding. The input current parameter was varied (150, 170 and 200nA) while maintaining the other welding parameters at constant values. An assessment of the mechanical (tensile and impact strength) and microstructure properties of the TIG-welded Al6061 MMC with 6 wt. % silicon carbide particles was accomplished. An 8.27% improvement was observed in ultimate tensile strength (UTS) for the 150 A TIG-welded sample. UTS and elasticity decreased linearly with an increase in welding current but exhibited higher values than in non-welded specimens. The microstructural analysis of the welded MMCs showed a mixed mode of failure, with equiaxial dimples being dominant in lower-weld-current specimens. Compared to non-welded specimens, a 40% increase in impact strength was observed for the 150 A TIG-welded specimens, which decreased with an increase in the welding current value. SEM analysis revealed ductile striations and continuous river patterns, resulting in mixed failure.
In this paper, metal matrix composites of Al6061 strengthened with 6 wt. % SiC were produced by stir casting and further subjected to the Tungsten Inert Gas (TIG) welding fabrication process using ER5356 as the filler material. The effect of TIG welding on hardness and wear resistance was studied by varying current at 150, 170, and 200 A. Samples of cast composite as per ASTM standards were prepared. Hardness tests on TIG-welded composite were carried out on the base, heat-affected, and weld zones. The test results showed higher hardness with an increase in welding current. Sliding wear properties were explored using the pin-on-disc machine. The wear rate and weight loss decreased as the welding current increased. The surface morphological images obtained through SEM indicated that the wear in the non-welded specimen was due to abrasion and delamination, whereas that of the welded specimen showed a reduced delamination and lower wear rate.