Stamping cracking of 3004 aluminum foil used in battery cases

Material and process optimization: Use annealed 3004 aluminum foil (H18 → O) and reduce its hardness to HV50-60 to improve ductility. Preheat at 200℃ for 1 hour before stamping to reduce work hardening. Use a stepped stamping process (initial punch depth ≤ 0.3mm, final punch speed ≤ 15mm/s), and use a silicone-based lubricant to reduce friction. Key control points include: Die corner radius ≥ 2 times the material thickness, and clearance controlled at 8%-10% of the material thickness to avoid stress concentration.

Crack verification and improvement: Metallographic examination of the cracked area reveals a 70% reduction in cracking rate. Comparative experiments show that optimization reduces the cracking rate by 70%. If localized cracking persists, increase the thickness by 0.05mm or switch to 3003 aluminum foil (which increases elongation by 3%-5%).