Assessment of Mechanical Behaviour Trends of Surface-Ground AA7075 Thin Plate Across Run Orders

AA7075 aluminium alloy thin plates are widely used in marine applications, particularly as skin panels for hydrofoil crafts, where surface grinding is an essential finishing operation. However, the influence of grinding parameters on mechanical behavior across different experimental run orders is not fully understood. This study examines the effects of surface grinding parameters on the mechanical properties of AA7075 thin plates, focusing on tensile strength, yield strength, elongation, and elastic modulus. Specimens were ground according to the experimental design schedule and tested using a DI-CP/V2 servo-hydraulic testing machine. Tensile and yield strengths exhibited similar fluctuation trends, with tensile strength consistently higher than yield strength. During runs 1–20, strength values were relatively low and stable, followed by a sharp increase between runs 23 and 27, where tensile and yield strengths reached approximately 170 MPa and 155 MPa, respectively. A slight reduction occurred during the mid-runs, while further peaks after run 40 indicated improved surface integrity under specific grinding conditions. Ductility analysis showed total elongation of 6–13%, exceeding uniform elongation of 4–6%, indicating a stronger influence on post-necking deformation. The elastic modulus varied between 10 and 33 GPa, showing mid-run fluctuation and stabilization toward the final runs.