Fiber-Laser Square Texturing of AA2024-T3: Scale Factor and Scanning Speed Effects on Contact Angle and Surface Profilometry

<p dir="ltr" style="line-height:1.295;margin-top:0pt;margin-bottom:8pt;"><span style="font-size:12pt;font-family:'Times New Roman',serif;color:#000000;background-color:transparent;font-weight:700;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre;white-space:pre-wrap;">Abstract</span> <span id="docs-internal-guid-88bfe3de-7fff-5981-069d-92734d2c88a1"></span> <p dir="ltr" style="line-height:1.3800000000000001;text-align: justify;margin-top:0pt;margin-bottom:8pt;"><span style="font-size:12pt;font-family:'Times New Roman',serif;color:#000000;background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline;white-space:pre;white-space:pre-wrap;">Laser square texturing of AA2024-T3 was used to tune wetting and topography by varying scale factor (SF = 100, 150, 250 µm) and scanning speed (250, 500, 750 mm s⁻¹). Relative to the untextured reference (θ = 92°), the textured surfaces delivered a broad contact-angle window of 75–107°. At SF = 100, θ changed from 94° (250) to 79° (500) and 107° (750); at SF = 150 from 96° (250) to 87° (500) and 85° (750); and at SF = 250 from 78° (250) to 75° (500) and 78° (750). Averaged over speed, increasing SF hydrophilized the alloy (mean θ: 93.3° to 89.3° and 77.0°), while speed showed a non-monotonic, scale-dependent effect: the 500 mm s⁻¹ group gave the lowest mean θ (80.3°), and 750 mm s⁻¹ enhanced hydrophobicity only at SF = 100. Areal roughness Sa ranged from 1.365 to 2.105 µm: low Sa occurred at SF = 250 with 250–750 mm s⁻¹ (1.366–1.365 µm) and at SF = 100 with 500 mm s⁻¹ (1.447 µm), whereas the roughest condition was SF = 100 at 750 mm s⁻¹ (2.105 µm). Optical images corroborated reduced recast/HAZ and crisper rims at higher speed. Overall, square texturing provides predictable wettability control on AA2024-T3 without chemistry. Future work should broaden the parameter space and assess durability and functional performance.</span>