Development of Al/Cu/SiC bimetallic nano-composite by friction stir spot welding

A joint of aluminum to copper sheets with a nanoparticle interlayer was successfully achieved by friction stir spot welding (FSSW). Effects of SiC reinforcing particles on the microstructure and mechanical performances of the joints were studied. It turned out that the introduction of nanoparticles during FSSW causes the microstructure refinement in the joint area and it develops the interface characteristics. Moreover, continuous CuAl2, CuAl, and Al4Cu9 phases developed at the interface joint, and the thickness of the intermetallic compound (IMCs) layer in the bond interface was decreased during FSSW with the nanoparticle. The results also implied that the mechanical properties of FSSW-ed samples with SiC particles, such as strength, are higher than that of conventional FSSW-ed specimens. Based on hardness measurements, hardness values in the stir zone were much higher due to higher stir action and refined grains.