Impurity Control when Coining Recycled-copper Blanks
回收铜坯压印的杂质控制
标签：回收铜, 杂质, 坯料, 压印
再生铜直接压印常见飞边早裂与模面拉伤，源头控制是关键：坯料铜含量 ≥99.5%、铅 ≤0.05%，铁镍杂质超 0.1% 就会在浮雕棱角显黑线。熔炼环节加 0.05% 磷铜脱氧，静置除渣后再铸坯；压前 700 ℃ 退火并酸洗。每批料先试压 20 件检查棱线填充，合格后放量。再生料成本可降 15–20%，但模具寿命会缩短 10–15%，报价时须把模耗摊入单价。
Coining recycled copper invites early flash cracking and die galling—control starts at the melt: keep blanks ≥99.5% Cu with lead ≤0.05%; iron/nickel above 0.1% shows as dark streaks at relief edges. Deoxidise with 0.05% phosphor copper, skim and rest the melt before casting blanks; anneal at 700 °C and pickle before striking. Trial-strike 20 pieces per batch for edge fill before ramping. Recycled stock saves 15–20% on material but shortens die life 10–15%—amortise the die wear into the quote.