CNC machining deformation reduction solution for 7075 aluminum sheets for mobile phone middle frames

Process optimization: A separate roughing and finishing strategy was adopted, with rough milling allowances controlled at 0.5-0.8mm. T73 aging treatment was performed before finishing to eliminate residual stress. PCD tools (rake angle 12°-15°) were used, with cutting parameters set at 12,000 rpm and 800 mm/min feed. Helical interpolation milling paths were used to reduce cutting force fluctuations. Key control points included pre-aging the blank (180℃ for 4 hours) before machining and freezing (-70℃ for 2 hours) after rough machining to stabilize dimensions.

Deformation verification: Three-dimensional coordinate measurement was used to measure flatness (≤0.02mm) and profile (≤0.05mm) after machining, combined with finite element simulation of thermal-stress coupled deformation during cutting. Comparative experiments showed that the optimized deformation was reduced by 60%, meeting the assembly tolerance requirements for mobile phone middle frames.