Manufacturing AA2024-AlB2 in-situ composites: How the traverse speed during friction stir processing influences microstructure and mechanical characteristics
摘要
The study investigates the application of friction stir processing on Al–AlB₂ composites, focusing on the influence of traverse speed on microstructure and mechanical performance. At 60 mm/min, the strain rate and peak temperature reach 23.2 s⁻1 and 421 °C, respectively, while at 20 mm/min they increase to 28.9 s⁻1 and 485 °C. Intermediate values at 40 mm/min promote an even distribution of particles within the aluminum matrix. Dynamic recrystallization in the stir zone produces pronounced grain refinement, reducing grain size from 4.7 µm at 20 mm/min to 0.9 µm at 60 mm/min. At this higher speed, combined with a rotational speed of 800 rpm, tensile strength increased by 11.8% to 508.2 MPa, while tensile toughness improved by 11.4% to 74.9 MJ/m3—surpassing the base AA2024 alloy, which exhibits a tensile strength of 454.3 MPa and a toughness of 67.2 MJ/m3.
Graphical abstract