Enhancing the Microstructure and Mechanical Properties of Cast Aluminum Matrix Composites Through Nano-Al₂O₃ Reinforcement via CMT and PMC Welding

In this investigation, two distinct composites were produced using the liquid metallurgy vortex-route method with an aluminum AA6013 matrix and 0.5% and 1% nano-Al₂O₃ reinforcement by weight. The effects of nano-Al₂O₃ ceramic particles added into the AA6013 alloy to increase the hardness and strength of the composite were investigated. Samples for welding were prepared from cast composite materials with dimensions of 250 × 110 × 60 mm. The obtained specimens were joined via butt welding at 110-A and 120-A current intensities, and at a constant speed of 400 mm/min by cold metal transfer (CMT) and pulse multi-control (PMC) welding methods. Using the use of micro- and macrostructural evaluations, hardness measurements, and tensile testing, the impacts of each welding parameter on the mechanical characteristics and weld structure of the cast composites were examined. The composite material with 0.5% nano-Al₂O₃ reinforcement that was joined at 120 A utilizing the CMT process achieved the highest tensile strength value at 96.6 MPa. At 110-A and 120-A welding current values, 0.5% reinforced composite demonstrated the maximum strength in both welding techniques.