Effect of TiC nanoparticles on the microstructure and mechanical properties of gas tungsten arc welded aluminum joints

In the present study, TiC/Al composite fillers of gas tungsten arc (GTA) welding with different contents of TiC nanoparticles were successfully fabricated by accumulative roll bonding (ARB). The purpose of ARB was to create a uniform distribution of TiC nanoparticles in the fillers and to form a good interfacial bonding between the aluminum matrix and TiC nanoparticles. The microstructure, mechanical properties and fracture surface morphology of the welds were investigated. It was found that TiC nanoparticles decreased the grain size of the primary alpha-Al phase due to the augmented nucleation and retarded growth. The tensile strength and hardness of weld improved with increasing TiC nanoparticle content. The improvement in the mechanical properties was attributed to the uniform distribution of TiC nanoparticles and grain refinement. Therefore, it can be concluded that the TiC/Al composite filler can serve as a suitable filler for GTA welding of aluminum and its alloys. (C) 2014 Elsevier B.V. All rights reserved.