Analysis and Optimization of Friction Stir Welding Process for AA6092/ZrO2 Composite Materials

Aluminum metal matrix composites (AMMCs) are created by incorporating various ceramic particles into aluminum alloys, offering enhanced mechanical properties and customizable thermal and electrical characteristics. Zirconium dioxide (ZrO2) is particularly valuable due to its excellent fracture toughness, wear resistance, low thermal conductivity, and high resistance to mechanical stress and cracking. Its compatibility with aluminum alloys makes it suitable for applications in medical products, electronic equipment, oxygen sensors, fuel cell membranes, and engine valve seats. Friction Stir Welding (FSW) is an emerging solid-state technique for joining AMMCs reinforced with particulate ceramics, effectively preserving their mechanical properties and reducing defects common in traditional fusion welding. This study aims to develop regression models that predict the Ultimate Tensile Strength (UTS), Percent Elongation (PE), and Weld Nugget Hardness (WNH) of friction stir welded AA6092 composites reinforced with ZrO2 particles. The models will correlate with key FSW parameters, including tool rotational speed (TRS), Welding Speed (WS), Axial Load (AL), and the percentage of ZrO2 reinforcement. Statistical software Design Expert, along with analysis of variance (ANOVA) and Student’s t-test, will be used to validate the developed models. Using Response Surface Methodology and ANOVA, optimized welding conditions were identified as TRS = 1208.09 rpm, WS = 51.5 mm/min, AL = 5.13 kN, and 15 wt.% ZrO2. Under these parameters, the highest mechanical properties achieved were UTS = 494.81 MPa, PE = 8.51%, and WNH = 184.57 HRB. The developed regression models demonstrated high accuracy, with prediction errors below ±5% for all responses. These results confirm the effectiveness of the proposed models and parameters for enhancing the mechanical performance of AA6092/ZrO2 FSW joints.