Fabrication and properties of ZrO 2 /AZ31 nanocomposite fillers of gas tungsten arc welding by accumulative roll bonding

In the present study, a new method for fabricating ZrO2/AZ31 nanocomposite fillers of gas tungsten arc (GTA) welding was developed by applying accumulative roll bonding (ARB) to the magnesium sheets coated with ZrO2 nanoparticles. The purpose of ARB was to create a uniform dispersion of ZrO2 nanoparticles in the fillers and to form a good interfacial bonding between the magnesium matrix and ZrO2 nanoparticles. After welding, the effect of ZrO2 nanoparticles on the microstructure and mechanical properties of weld was evaluated. The test results showed that the yield strength of weld was greatly increased when using the nanocomposite fillers. The improvement in the yield strength was attributed to the grain refinement, coefficient of thermal expansion mismatch and Orowan strengthening mechanisms.