In this research work, the effect of SiC and Al2O3 reinforcements is analyzed on the interlock dissimilar joints. The joints are welded with different wt% of SiC and Al2O3 (1 to 5 wt%) placed in the groove of 0.5 mm depth between the sheets. The rotational speed of 1400 rpm, weld speed of 30 mm/s and plunge speed rate of 0.06 mm/s are selected input parameters to perform the weld. Thereafter Micro-hardness, tensile strength and microstructure properties of interlock lap joints were investigated. AA7075 T6–AA7475 T7/2wt% SiC showed maximum tensile strength and hardness of 190.51 MPa, 220 HV respectively. All the SiC reinforced FSW interlock lap joints mechanical properties showed improvement on the static properties than the joints made with Al2O3 reinforcement, because of the hard silica particles and substantial increase in grain refinement that occurred in the stir zone of the reinforced welded joints. The microstructure analysis of joints revealed that reinforcements have mixed uniformly and homogenous distribution occurred in the entire weld. The fracture analysis revealed that the joints with SiC possess ductile fracture. © 2020, Springer Nature B.V.