Troubleshooting Sinking Defects in Recycled Copper
再生铜板下凹起皱与撕裂排查
标签：再生铜, 起皱, 撕裂, 夹杂, 材料排查
再生铜含铅、铁与氧化物杂质较多，下凹时更易起皱与沿晶撕裂。排查：①退火后查晶粒，晶粒粗大则缩短保温（650 ℃×10–15 min 改 5–8 min）；②裂口沿黑色夹杂线分布说明杂质富集，需换铜含量 99.9% 以上的电解再生板；③起皱则加大压边、垫聚氨酯并放慢走料节奏。每批料先做 φ20 mm 试片压窝验证延伸率，再正式投产。
Recycled copper carries more lead, iron and oxide inclusions, so sinking wrinkles and tears intergranularly more easily. Check: (1) grain size after annealing—if coarse, cut soak from 650 °C × 10–15 min to 5–8 min; (2) if fracture lines follow black inclusion streaks, switch to electrolytic recycled sheet ≥99.9% Cu; (3) for wrinkles, increase blank-holding, add a polyurethane pad and slow the sinking rhythm. Prove elongation with a φ20 mm test disc from every batch before production.