1. 不銹鋼(gang)化學鍍銅(tong)的應用
不銹鋼化學(xue)鍍銅(tong)應用于電(dian)子(zi)(zi)工(gong)業(ye)、計(ji)算機工(gong)業(ye)及航空(kong)工(gong)業(ye)中(zhong)電(dian)子(zi)(zi)元件的高效電(dian)磁(ci)干(gan)擾的屏蔽(bi)。
2. 不銹(xiu)鋼基(ji)體上化學鍍銅存在(zai)的問題(ti)
香蕉視頻app在線觀看: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. 不銹鋼化學鍍銅工藝流程
NiCr不(bu)銹(xiu)鋼(經過600℃真空熱處理(li))→化學(xue)(xue)除(chu)油[氫氧化鈉(na)(NaOH)10%(質(zhi)量分(fen)數)]→水(shui)(shui)洗(xi)(xi)(xi)→熱水(shui)(shui)洗(xi)(xi)(xi)→除(chu)銹(xiu)(鹽酸(suan)1:1溶(rong)液,溫(wen)度(du)(du)80~100℃,時間(jian)5min)→水(shui)(shui)洗(xi)(xi)(xi)→干燥→除(chu)氫(在烘箱中溫(wen)度(du)(du)200℃,時間(jian)2h)→酸(suan)處理(li)[稀(xi)硫酸(suan)5%(質(zhi)量分(fen)數),時間(jian)1~5min]→水(shui)(shui)洗(xi)(xi)(xi)→去離子水(shui)(shui)洗(xi)(xi)(xi)→化學(xue)(xue)鍍銅→水(shui)(shui)洗(xi)(xi)(xi)→抗銅變色(se)處理(li)(苯(ben)并三(san)氮(dan)唑1g/L,溫(wen)度(du)(du)65℃,時間(jian)2min)→純(chun)水(shui)(shui)洗(xi)(xi)(xi)→熱純(chun)水(shui)(shui)洗(xi)(xi)(xi)→干燥。
4. 化學鍍銅(tong)溶液成分及工藝條(tiao)件見表4-39
5. 化學鍍銅(tong)溶液(ye)的配制
先將(jiang)(jiang)硫酸銅(tong)和酒(jiu)石(shi)酸鉀(jia)(jia)鈉(na)(na)分(fen)別用(yong)(yong)純(chun)水(shui)溶(rong)(rong)解(jie),然后將(jiang)(jiang)硫酸銅(tong)溶(rong)(rong)液在(zai)(zai)攪(jiao)拌(ban)(ban)下加(jia)入(ru)酒(jiu)石(shi)酸鉀(jia)(jia)鈉(na)(na)溶(rong)(rong)液中(zhong),銅(tong)離子(zi)被(bei)酒(jiu)石(shi)酸離子(zi)絡合(he)(he)成藍色絡合(he)(he)物。再將(jiang)(jiang)氯(lv)(lv)化(hua)(hua)(hua)鎳用(yong)(yong)少量(liang)水(shui)溶(rong)(rong)解(jie)后攪(jiao)拌(ban)(ban)加(jia)入(ru),再加(jia)入(ru)甲醛溶(rong)(rong)液,攪(jiao)拌(ban)(ban)均(jun)勻(yun)。將(jiang)(jiang)氫氧化(hua)(hua)(hua)鈉(na)(na)用(yong)(yong)純(chun)水(shui)溶(rong)(rong)解(jie)成200g/L 的濃(nong)溶(rong)(rong)液待用(yong)(yong)。在(zai)(zai)開始化(hua)(hua)(hua)學鍍(du)銅(tong)前,逐步(bu)在(zai)(zai)攪(jiao)拌(ban)(ban)下加(jia)入(ru)藍色絡合(he)(he)液中(zhong),使溶(rong)(rong)液pH達(da)到12 左右(用(yong)(yong)9~13精密pH試(shi)紙測量(liang)),最后將(jiang)(jiang)穩定(ding)劑亞鐵(tie)氯(lv)(lv)化(hua)(hua)(hua)鉀(jia)(jia)、聚(ju)乙二醇用(yong)(yong)少量(liang)水(shui)溶(rong)(rong)解(jie)后攪(jiao)拌(ban)(ban)加(jia)入(ru),乙醇可直接加(jia)入(ru),最后用(yong)(yong)純(chun)水(shui)加(jia)入(ru)至溶(rong)(rong)液的規(gui)定(ding)體積,攪(jiao)拌(ban)(ban)均(jun)勻(yun)后放入(ru)不銹(xiu)鋼件即可開始化(hua)(hua)(hua)學鍍(du)銅(tong)。
6. 操作(zuo)要點
①. 裝(zhuang)載(zai)量
按照每升鍍液(ye)裝載2d㎡計(ji)算。
②. 除氫和攪拌
不銹鋼對氫(qing)(qing)(qing)滲(shen)很(hen)敏(min)感,工(gong)件在(zai)(zai)酸(suan)洗過(guo)(guo)(guo)(guo)程中(zhong)氫(qing)(qing)(qing)會(hui)滲(shen)人到(dao)基(ji)(ji)(ji)體(ti)中(zhong),如果不除(chu)(chu)氫(qing)(qing)(qing),化(hua)學(xue)(xue)鍍(du)(du)銅鍍(du)(du)層(ceng)致密小孔(kong)覆蓋在(zai)(zai)不銹鋼表(biao)(biao)面(mian)后,氫(qing)(qing)(qing)氣無法逸(yi)出,造成(cheng)很(hen)大(da)的(de)(de)(de)(de)應(ying)力(li),使鍍(du)(du)層(ceng)起(qi)泡(pao),加上(shang)化(hua)學(xue)(xue)鍍(du)(du)銅本身伴隨(sui)著析氫(qing)(qing)(qing)過(guo)(guo)(guo)(guo)程,氫(qing)(qing)(qing)氣會(hui)殘留在(zai)(zai)基(ji)(ji)(ji)體(ti)與鍍(du)(du)層(ceng)金屬(shu)的(de)(de)(de)(de)晶格中(zhong),增(zeng)大(da)內應(ying)力(li),嚴重地減(jian)弱基(ji)(ji)(ji)體(ti)與鍍(du)(du)層(ceng)的(de)(de)(de)(de)結(jie)合強度(du)(du)。為(wei)此,從兩(liang)方(fang)面(mian)著手解決(jue)鍍(du)(du)層(ceng)起(qi)泡(pao)問(wen)題。其一是把經過(guo)(guo)(guo)(guo)去(qu)(qu)油、酸(suan)洗后的(de)(de)(de)(de)工(gong)件在(zai)(zai)化(hua)學(xue)(xue)鍍(du)(du)銅前進行(xing)熱(re)處理,除(chu)(chu)去(qu)(qu)滲(shen)入到(dao)基(ji)(ji)(ji)體(ti)中(zhong)的(de)(de)(de)(de)氫(qing)(qing)(qing),熱(re)處理溫(wen)度(du)(du)和(he)時(shi)(shi)間條(tiao)件經實驗確定為(wei)180~200℃,2小時(shi)(shi),鍍(du)(du)層(ceng)無鼓(gu)泡(pao),鍍(du)(du)層(ceng)結(jie)合力(li)合格。溫(wen)度(du)(du)過(guo)(guo)(guo)(guo)低(di)或時(shi)(shi)間過(guo)(guo)(guo)(guo)短仍有(you)輕微鼓(gu)泡(pao),溫(wen)度(du)(du)過(guo)(guo)(guo)(guo)高(gao)或時(shi)(shi)間過(guo)(guo)(guo)(guo)長都容易使表(biao)(biao)面(mian)再(zai)次(ci)生成(cheng)不易去(qu)(qu)除(chu)(chu)的(de)(de)(de)(de)氧(yang)化(hua)皮(pi),又需(xu)要較長時(shi)(shi)間的(de)(de)(de)(de)強酸(suan)處理,酸(suan)洗時(shi)(shi)氫(qing)(qing)(qing)會(hui)再(zai)次(ci)滲(shen)入基(ji)(ji)(ji)體(ti)。在(zai)(zai)所選定的(de)(de)(de)(de)溫(wen)度(du)(du)和(he)時(shi)(shi)間下雖表(biao)(biao)面(mian)會(hui)有(you)新的(de)(de)(de)(de)氧(yang)化(hua)膜生成(cheng),但使用稀硫酸(suan)短時(shi)(shi)間酸(suan)洗即(ji)(ji)可,以免(mian)再(zai)次(ci)滲(shen)氫(qing)(qing)(qing)。其二是在(zai)(zai)化(hua)學(xue)(xue)鍍(du)(du)銅過(guo)(guo)(guo)(guo)程中(zhong),采用某種(zhong)攪拌(ban)(空氣攪拌(ban)或機械攪拌(ban)),有(you)利(li)(li)于(yu)銅離(li)(li)子向工(gong)件表(biao)(biao)面(mian)擴散,防止和(he)減(jian)少副反(fan)應(ying)產物銅粉(fen)(即(ji)(ji)Cu2O)的(de)(de)(de)(de)生成(cheng),而(er)且有(you)利(li)(li)于(yu)反(fan)應(ying)產物氫(qing)(qing)(qing)氣脫離(li)(li)工(gong)件表(biao)(biao)面(mian)。通過(guo)(guo)(guo)(guo)上(shang)述兩(liang)種(zhong)方(fang)法有(you)效地解決(jue)了鍍(du)(du)層(ceng)鼓(gu)泡(pao)問(wen)題,提高(gao)了鍍(du)(du)層(ceng)與基(ji)(ji)(ji)體(ti)的(de)(de)(de)(de)結(jie)合強度(du)(du)。
③. 催化活性劑-鎳(nie)離子
在化(hua)(hua)學鍍銅溶液中加入少量鎳離子后,鍍層性質得到改善,在鍍銅層中含有(you)微量的鎳,形(xing)成Cu89Ni11金屬(shu)化(hua)(hua)合物,它具有(you)最佳的催化(hua)(hua)活(huo)性,提高鍍層的催化(hua)(hua)活(huo)性。
④. 穩(wen)定劑(ji)的控(kong)制
在化(hua)(hua)學鍍銅(tong)過程中(zhong),甲醛能將二價銅(tong)離(li)子還原為金屬(shu)銅(tong)鍍層(ceng),還存在有(you)副(fu)反(fan)(fan)應(ying)(ying),即不完全(quan)反(fan)(fan)應(ying)(ying)生成暗紅色的(de)(de)(de)氧(yang)化(hua)(hua)亞銅(tong)(Cu2O),它形(xing)成微粒懸浮在鍍液(ye)中(zhong),呈膠體(ti)狀(zhuang)態(tai),極難(nan)用(yong)過濾(lv)除去,若(ruo)與銅(tong)共沉積,使銅(tong)鍍層(ceng)疏松粗糙,與基體(ti)結(jie)合力極差(cha)。氧(yang)化(hua)(hua)亞銅(tong)被(bei)甲醛還原成金屬(shu)微粒,又(you)成為自催化(hua)(hua)中(zhong)心,使鍍液(ye)自發分(fen)解,消耗了鍍液(ye)中(zhong)的(de)(de)(de)有(you)效成分(fen)。為了抑制副(fu)反(fan)(fan)應(ying)(ying)的(de)(de)(de)發生,加入穩(wen)(wen)定(ding)(ding)劑,以提(ti)高(gao)鍍液(ye)的(de)(de)(de)穩(wen)(wen)定(ding)(ding)性(xing)。但是,過量(liang)的(de)(de)(de)穩(wen)(wen)定(ding)(ding)劑的(de)(de)(de)加人,又(you)成了化(hua)(hua)學鍍銅(tong)反(fan)(fan)應(ying)(ying)的(de)(de)(de)催化(hua)(hua)毒性(xing)劑,顯著降(jiang)低化(hua)(hua)學鍍的(de)(de)(de)速率(lv),甚至(zhi)停(ting)鍍,故(gu)選用(yong)穩(wen)(wen)定(ding)(ding)劑,并控制其很低的(de)(de)(de)適宜含量(liang),對提(ti)高(gao)鍍液(ye)穩(wen)(wen)定(ding)(ding)性(xing)有(you)效。
⑤. 防銅層(ceng)變色處理
對(dui)銅層(ceng)進行防變色(se)(se)處理(li),在鍍銅層(ceng)表面形(xing)成一(yi)層(ceng)穩定(ding)的(de)絡合膜,隔絕外界浸蝕(shi)性物質對(dui)鍍銅層(ceng)的(de)作用,使鍍銅層(ceng)保持本色(se)(se)一(yi)定(ding)的(de)時間(jian)。苯并三氮唑要先用乙醇(chun)溶解好(hao),然后加入熱(re)蒸餾水中。防變色(se)(se)處理(li)的(de)溫度不低于(yu)65℃,時間(jian)不少于(yu)2min,否(fou)則防變色(se)(se)達不到(dao)效果。
7. 鍍層結合強(qiang)度檢測-劃痕實驗法
在鍍(du)(du)層表面(mian)用刀片(pian)劃出1mm間距(ju)的直行(xing)線(xian)和90°交錯(cuo)的橫行(xing)線(xian)形成小方(fang)格(ge)。觀察劃痕交錯(cuo)處鍍(du)(du)層有無(wu)起層,進一步用黏性高的膠帶貼(tie)于劃痕表面(mian),再撕下膠帶,以銅層不脫落為(wei)合格(ge)。
8. 不銹鋼化學鍍銅常見(jian)故障(zhang)、可能(neng)原因及(ji)糾(jiu)正方法見(jian)表(biao)4-40.