1. 不銹鋼化學鍍銅(tong)的應用
不(bu)銹鋼化學鍍銅應用于電(dian)(dian)子工業、計(ji)算機(ji)工業及航空工業中(zhong)電(dian)(dian)子元件的(de)高效(xiao)電(dian)(dian)磁干(gan)擾(rao)的(de)屏(ping)蔽。
2. 不銹鋼基(ji)體上化學(xue)鍍銅存在的問題
香蕉視頻app下載蘋果版:不銹鋼基體上化學鍍銅易造成鍍層鼓泡,這不僅影響了鍍層與基體的結合力,而且直接影響到外觀質量。為此,將鍍前酸處理過的不銹鋼放在烘箱中加熱,以除去酸洗時滲入到基體的氫,采用此方法解決了鍍層起泡問題,得到所需要的化學鍍銅層。
3. 不(bu)銹鋼化學鍍銅工藝流(liu)程
NiCr不(bu)銹(xiu)鋼(經過(guo)600℃真空(kong)熱(re)處理)→化學除(chu)油[氫氧化鈉(NaOH)10%(質(zhi)量分數(shu))]→水(shui)(shui)(shui)洗→熱(re)水(shui)(shui)(shui)洗→除(chu)銹(xiu)(鹽酸1:1溶液(ye),溫度(du)80~100℃,時間5min)→水(shui)(shui)(shui)洗→干燥→除(chu)氫(在烘箱中溫度(du)200℃,時間2h)→酸處理[稀硫酸5%(質(zhi)量分數(shu)),時間1~5min]→水(shui)(shui)(shui)洗→去離(li)子水(shui)(shui)(shui)洗→化學鍍銅(tong)(tong)→水(shui)(shui)(shui)洗→抗銅(tong)(tong)變色(se)處理(苯并(bing)三(san)氮唑1g/L,溫度(du)65℃,時間2min)→純水(shui)(shui)(shui)洗→熱(re)純水(shui)(shui)(shui)洗→干燥。
4. 化(hua)學(xue)鍍銅溶液成分及(ji)工藝(yi)條件見表4-39
5. 化(hua)學鍍(du)銅溶(rong)液的配制
先將硫(liu)(liu)酸(suan)(suan)銅(tong)和酒石酸(suan)(suan)鉀鈉分別用(yong)純水溶(rong)(rong)(rong)(rong)解(jie),然后(hou)將硫(liu)(liu)酸(suan)(suan)銅(tong)溶(rong)(rong)(rong)(rong)液(ye)在攪拌(ban)下加入(ru)(ru)酒石酸(suan)(suan)鉀鈉溶(rong)(rong)(rong)(rong)液(ye)中,銅(tong)離子被酒石酸(suan)(suan)離子絡(luo)合成藍色(se)絡(luo)合物。再將氯化鎳用(yong)少量水溶(rong)(rong)(rong)(rong)解(jie)后(hou)攪拌(ban)加入(ru)(ru),再加入(ru)(ru)甲醛溶(rong)(rong)(rong)(rong)液(ye),攪拌(ban)均勻。將氫(qing)氧化鈉用(yong)純水溶(rong)(rong)(rong)(rong)解(jie)成200g/L 的濃溶(rong)(rong)(rong)(rong)液(ye)待(dai)用(yong)。在開始(shi)化學(xue)鍍(du)銅(tong)前,逐步在攪拌(ban)下加入(ru)(ru)藍色(se)絡(luo)合液(ye)中,使(shi)溶(rong)(rong)(rong)(rong)液(ye)pH達到(dao)12 左右(用(yong)9~13精密pH試紙(zhi)測量),最后(hou)將穩定劑亞鐵(tie)氯化鉀、聚乙(yi)二(er)醇用(yong)少量水溶(rong)(rong)(rong)(rong)解(jie)后(hou)攪拌(ban)加入(ru)(ru),乙(yi)醇可(ke)直接加入(ru)(ru),最后(hou)用(yong)純水加入(ru)(ru)至溶(rong)(rong)(rong)(rong)液(ye)的規定體(ti)積,攪拌(ban)均勻后(hou)放入(ru)(ru)不(bu)銹鋼件即(ji)可(ke)開始(shi)化學(xue)鍍(du)銅(tong)。
6. 操(cao)作(zuo)要點
①. 裝(zhuang)載量
按照每升鍍(du)液(ye)裝(zhuang)載2d㎡計算。
②. 除氫(qing)和攪拌
不銹(xiu)鋼(gang)(gang)對氫(qing)(qing)滲(shen)(shen)很敏感,工件(jian)在(zai)酸(suan)洗(xi)(xi)(xi)過(guo)程中氫(qing)(qing)會(hui)滲(shen)(shen)人到基(ji)體中,如果不除(chu)(chu)氫(qing)(qing),化(hua)(hua)(hua)學鍍(du)(du)(du)銅(tong)鍍(du)(du)(du)層(ceng)(ceng)致密小(xiao)孔覆蓋在(zai)不銹(xiu)鋼(gang)(gang)表(biao)(biao)面后,氫(qing)(qing)氣(qi)無法(fa)逸出,造成(cheng)很大(da)的(de)(de)應力(li),使鍍(du)(du)(du)層(ceng)(ceng)起泡(pao)(pao),加上(shang)化(hua)(hua)(hua)學鍍(du)(du)(du)銅(tong)本(ben)身伴隨著析氫(qing)(qing)過(guo)程,氫(qing)(qing)氣(qi)會(hui)殘留(liu)在(zai)基(ji)體與鍍(du)(du)(du)層(ceng)(ceng)金(jin)屬的(de)(de)晶(jing)格(ge)中,增大(da)內應力(li),嚴重地減弱基(ji)體與鍍(du)(du)(du)層(ceng)(ceng)的(de)(de)結合(he)強(qiang)度(du)。為此,從(cong)兩方(fang)面著手解決鍍(du)(du)(du)層(ceng)(ceng)起泡(pao)(pao)問(wen)題(ti)。其(qi)一(yi)是(shi)把(ba)經過(guo)去(qu)油(you)、酸(suan)洗(xi)(xi)(xi)后的(de)(de)工件(jian)在(zai)化(hua)(hua)(hua)學鍍(du)(du)(du)銅(tong)前進行(xing)熱處理,除(chu)(chu)去(qu)滲(shen)(shen)入到基(ji)體中的(de)(de)氫(qing)(qing),熱處理溫度(du)和(he)時(shi)間條件(jian)經實驗確(que)定(ding)為180~200℃,2小(xiao)時(shi),鍍(du)(du)(du)層(ceng)(ceng)無鼓泡(pao)(pao),鍍(du)(du)(du)層(ceng)(ceng)結合(he)力(li)合(he)格(ge)。溫度(du)過(guo)低或(huo)時(shi)間過(guo)短仍有(you)輕微鼓泡(pao)(pao),溫度(du)過(guo)高或(huo)時(shi)間過(guo)長(chang)都容易(yi)使表(biao)(biao)面再(zai)次生成(cheng)不易(yi)去(qu)除(chu)(chu)的(de)(de)氧化(hua)(hua)(hua)皮,又需要較長(chang)時(shi)間的(de)(de)強(qiang)酸(suan)處理,酸(suan)洗(xi)(xi)(xi)時(shi)氫(qing)(qing)會(hui)再(zai)次滲(shen)(shen)入基(ji)體。在(zai)所(suo)選定(ding)的(de)(de)溫度(du)和(he)時(shi)間下(xia)雖表(biao)(biao)面會(hui)有(you)新的(de)(de)氧化(hua)(hua)(hua)膜生成(cheng),但使用稀硫酸(suan)短時(shi)間酸(suan)洗(xi)(xi)(xi)即(ji)可(ke),以(yi)免再(zai)次滲(shen)(shen)氫(qing)(qing)。其(qi)二(er)是(shi)在(zai)化(hua)(hua)(hua)學鍍(du)(du)(du)銅(tong)過(guo)程中,采用某種(zhong)攪拌(ban)(空氣(qi)攪拌(ban)或(huo)機械攪拌(ban)),有(you)利于銅(tong)離子向工件(jian)表(biao)(biao)面擴(kuo)散,防止(zhi)和(he)減少副反應產物(wu)銅(tong)粉(即(ji)Cu2O)的(de)(de)生成(cheng),而且有(you)利于反應產物(wu)氫(qing)(qing)氣(qi)脫離工件(jian)表(biao)(biao)面。通過(guo)上(shang)述兩種(zhong)方(fang)法(fa)有(you)效(xiao)地解決了鍍(du)(du)(du)層(ceng)(ceng)鼓泡(pao)(pao)問(wen)題(ti),提高了鍍(du)(du)(du)層(ceng)(ceng)與基(ji)體的(de)(de)結合(he)強(qiang)度(du)。
③. 催化活性劑(ji)-鎳(nie)離(li)子
在(zai)化(hua)學鍍銅(tong)溶液(ye)中(zhong)加入少量(liang)(liang)鎳(nie)離子(zi)后,鍍層(ceng)性質(zhi)得到改善,在(zai)鍍銅(tong)層(ceng)中(zhong)含有微(wei)量(liang)(liang)的鎳(nie),形成Cu89Ni11金(jin)屬化(hua)合物,它具有最佳(jia)的催化(hua)活(huo)性,提高鍍層(ceng)的催化(hua)活(huo)性。
④. 穩定(ding)劑(ji)的控制(zhi)
在(zai)(zai)化學(xue)鍍(du)(du)(du)銅(tong)(tong)(tong)過(guo)程中(zhong),甲(jia)醛(quan)能將(jiang)二價(jia)銅(tong)(tong)(tong)離子還(huan)原(yuan)為(wei)金(jin)屬(shu)銅(tong)(tong)(tong)鍍(du)(du)(du)層,還(huan)存在(zai)(zai)有(you)副反應(ying)(ying),即不完全(quan)反應(ying)(ying)生成(cheng)暗(an)紅色(se)的氧化亞(ya)銅(tong)(tong)(tong)(Cu2O),它形成(cheng)微(wei)粒懸(xuan)浮在(zai)(zai)鍍(du)(du)(du)液(ye)(ye)中(zhong),呈膠體狀(zhuang)態,極難用(yong)過(guo)濾除去,若與銅(tong)(tong)(tong)共(gong)沉積,使銅(tong)(tong)(tong)鍍(du)(du)(du)層疏松粗(cu)糙,與基體結合力(li)極差。氧化亞(ya)銅(tong)(tong)(tong)被甲(jia)醛(quan)還(huan)原(yuan)成(cheng)金(jin)屬(shu)微(wei)粒,又成(cheng)為(wei)自催化中(zhong)心,使鍍(du)(du)(du)液(ye)(ye)自發分解(jie),消耗了鍍(du)(du)(du)液(ye)(ye)中(zhong)的有(you)效成(cheng)分。為(wei)了抑制(zhi)副反應(ying)(ying)的發生,加入(ru)穩(wen)(wen)定(ding)劑,以提高鍍(du)(du)(du)液(ye)(ye)的穩(wen)(wen)定(ding)性。但(dan)是,過(guo)量的穩(wen)(wen)定(ding)劑的加人,又成(cheng)了化學(xue)鍍(du)(du)(du)銅(tong)(tong)(tong)反應(ying)(ying)的催化毒性劑,顯著降低(di)化學(xue)鍍(du)(du)(du)的速率(lv),甚至停(ting)鍍(du)(du)(du),故選(xuan)用(yong)穩(wen)(wen)定(ding)劑,并(bing)控制(zhi)其很低(di)的適宜含量,對提高鍍(du)(du)(du)液(ye)(ye)穩(wen)(wen)定(ding)性有(you)效。
⑤. 防銅層(ceng)變色(se)處理
對銅(tong)層(ceng)進行(xing)防變色(se)處(chu)理,在鍍銅(tong)層(ceng)表面形成一層(ceng)穩定(ding)的絡合膜,隔絕外界浸(jin)蝕性物質對鍍銅(tong)層(ceng)的作用,使鍍銅(tong)層(ceng)保(bao)持(chi)本色(se)一定(ding)的時間(jian)。苯并三氮(dan)唑要先用乙醇溶解(jie)好,然后加入(ru)熱(re)蒸餾(liu)水(shui)中。防變色(se)處(chu)理的溫(wen)度不低于(yu)65℃,時間(jian)不少于(yu)2min,否(fou)則防變色(se)達不到效果。
7. 鍍層結合強度檢測-劃痕(hen)實驗(yan)法
在鍍(du)(du)層(ceng)(ceng)表面(mian)用(yong)刀(dao)片劃出1mm間距的(de)直行線和90°交(jiao)錯的(de)橫(heng)行線形成小方格。觀察劃痕交(jiao)錯處鍍(du)(du)層(ceng)(ceng)有(you)無起層(ceng)(ceng),進(jin)一步用(yong)黏性高的(de)膠(jiao)帶貼(tie)于劃痕表面(mian),再(zai)撕下膠(jiao)帶,以銅層(ceng)(ceng)不脫(tuo)落為合格。
8. 不銹鋼化學鍍銅常見故障(zhang)、可能原因及糾正方(fang)法見表4-40.