1. 酸性錫(xi)電刷鍍液(ye)的性質
酸性錫電刷鍍液為無色透明溶液,呈酸性,錫離子含量130g/L,20℃時相對密度為1.25,電導率為3.18×10-1Ω-1·cm-1,冰點 -10℃.鍍液溫度高時,工作電流大,生產效率高,鍍液供應一定要充分,這樣可避免鍍層氧化,提高鍍層與基體的結合力。
2. 酸性錫電刷鍍層(ceng)的性能(neng)與用途
酸性(xing)錫鍍液在低(di)電(dian)(dian)壓下(xia)刷鍍所得的鍍層光潔,呈白灰色,電(dian)(dian)流(liu)小,效率(lv)低(di)。在高(gao)電(dian)(dian)壓下(xia)刷鍍鍍層逐漸(jian)變成淡灰色,電(dian)(dian)流(liu)增大,效率(lv)高(gao),表(biao)面結晶粗(cu)糙。
酸性錫經過(guo)電凈與活(huo)化后可直接刷(shua)鍍到(dao)不銹鋼上。主要用于防氮化,以(yi)及劃傷和凹坑的(de)填補(bu),改(gai)善零件間的(de)配合(he)(he)性能(neng),提高磨合(he)(he)密封(feng)性。
3. 酸性錫電(dian)刷鍍液的成分
硫酸亞錫(SnSO4) 200g/L 、 草酸(H2C2O4) 5g/L 、 pH 1~1.5
氟化銨(NH4F) 40g/L 、β-萘酚 1g/L 、酒石酸(H2C4H4O6) 20g/L
4. 酸(suan)性錫電刷鍍液的配制
在(zai)(zai)1000mL燒杯(bei)(bei)中(zhong)(zhong)(zhong),加(jia)(jia)蒸餾(liu)(liu)水(shui)600mL,加(jia)(jia)熱(re)至70℃,加(jia)(jia)入(ru)(ru)(ru)硫酸(suan)(suan)亞(ya)錫(xi)200g,維(wei)續加(jia)(jia)熱(re)攪(jiao)拌(ban)(ban)(ban)直至完全(quan)溶(rong)解。在(zai)(zai)250mL燒杯(bei)(bei)中(zhong)(zhong)(zhong)加(jia)(jia)蒸餾(liu)(liu)水(shui)100ml,加(jia)(jia)入(ru)(ru)(ru)氯化銨(an)40g攪(jiao)拌(ban)(ban)(ban)溶(rong)解,加(jia)(jia)入(ru)(ru)(ru)硫酸(suan)(suan)亞(ya)錫(xi)溶(rong)液(ye)中(zhong)(zhong)(zhong),攪(jiao)拌(ban)(ban)(ban)均勻,在(zai)(zai)250mL燒杯(bei)(bei)中(zhong)(zhong)(zhong),加(jia)(jia)入(ru)(ru)(ru)蒸餾(liu)(liu)水(shui)100mL,加(jia)(jia)熱(re)至70℃,加(jia)(jia)入(ru)(ru)(ru)酒(jiu)石(shi)酸(suan)(suan)20g,草酸(suan)(suan)5g, 攪(jiao)拌(ban)(ban)(ban)溶(rong)解后(hou),加(jia)(jia)入(ru)(ru)(ru)硫酸(suan)(suan)亞(ya)錫(xi)溶(rong)液(ye)中(zhong)(zhong)(zhong),攪(jiao)拌(ban)(ban)(ban)均勻。在(zai)(zai)另一個(ge)50mL燒杯(bei)(bei)中(zhong)(zhong)(zhong),加(jia)(jia)入(ru)(ru)(ru) β-萘酚1g , 加(jia)(jia)入(ru)(ru)(ru)甲醇數毫升,攪(jiao)拌(ban)(ban)(ban)溶(rong)解后(hou),在(zai)(zai)攪(jiao)拌(ban)(ban)(ban)下(xia)加(jia)(jia)入(ru)(ru)(ru)硫酸(suan)(suan)亞(ya)錫(xi)溶(rong)液(ye)中(zhong)(zhong)(zhong),用10% 稀硫酸(suan)(suan)調(diao)整pH=1~1.5,將整個(ge)溶(rong)液(ye)倒(dao)入(ru)(ru)(ru)1000mL量簡或量瓶中(zhong)(zhong)(zhong),加(jia)(jia)蒸餾(liu)(liu)水(shui)至刻度。盛于(yu)塑料(liao)容(rong)器中(zhong)(zhong)(zhong)保存(cun)。
5. 使用方法和工(gong)藝規范
工作溫(wen)度:10~60℃;
耗電系數:0.07A·h/(d㎡·μm);
工(gong)作電(dian)壓:6~15V(最佳8~10V),電(dian)壓高于15V,電(dian)流(liu)并(bing)無明顯增(zeng)加,陽(yang)極包套中的鍍液(ye)出(chu)現沸騰,鍍層粗糙;
陰陽極(ji)相對(dui)運動速(su)率:20~40m/min,如果相對(dui)運動速(su)率過小,<10m/min,在(zai)其他條件正常時,鍍(du)層厚度(du)大(da)于0.2mm時呈黑褐色粗糙層,結合力(li)極(ji)差,用(yong)手即可搓掉(diao),鍍(du)層完全沒(mei)有延(yan)展性(xing),無實際使用(yong)價值(zhi),通常相對(dui)運動速(su)率必須(xu)大(da)于20m/min;
鍍(du)(du)液(ye)(ye)循環(huan)使用(yong)(yong)周期:鍍(du)(du)液(ye)(ye)在循環(huan)使用(yong)(yong)過程(cheng)中,當刷鍍(du)(du)液(ye)(ye)容積消耗到60%時,錫(xi)離(li)子由(you)130g/L降到55g/L,已有75%的錫(xi)被沉(chen)積出來,酸(suan)性錫(xi)刷鍍(du)(du)液(ye)(ye)屬空乏(fa)型鍍(du)(du)液(ye)(ye),沉(chen)積速率(lv)由(you)快(kuai)變慢,鍍(du)(du)液(ye)(ye)的pH基(ji)本穩(wen)定,建(jian)議停止使用(yong)(yong),應回收處理后再用(yong)(yong)。

