Lead-free Niello Alloys

现代无铅乌银配方

type:recipe · level:intermediate · material:silver · material:copper · variant:sulfide · scale:jewelry · scale:decorative-object · equipment:torch · equipment:hand-tools · stage:chasing · stage:patina

传统乌银含铅 10–30%（降熔点利填充），现代无铅配方以「银 65 / 铜 20 / 硫化铜 10 / 锌 5」或市售硫化银+低熔点银焊料复合方案替代：熔点 680–720 ℃、填充流动性接近含铅传统料，黑色饱和度略浅可二次硫化加深。欧盟 EN 1811 镍/铅释放限值下，无铅乌银已成出口饰品唯一合规选择。熔制时通风+口罩（硫蒸气），浇入石墨模冷却成锭。

Traditional niello carries 10–30% lead for fluidity; modern lead-free mixes (Ag 65 / Cu 20 / CuS 10 / Zn 5, mp 680–720 °C) fill comparably though slightly less black—a second sulfiding pass deepens the tone. Under EN 1811 nickel/lead limits, lead-free niello is the only compliant choice for export jewelry. Melt with ventilation and a mask (sulfur fumes), casting ingots in graphite. ---