摘要(yao)

采(cai)取(qu)模擬大(da)(da)氣環(huan)境的(de)(de)(de)室內中(zhong)性鹽霧(wu)腐(fu)(fu)(fu)蝕(shi)(shi)實驗，探(tan)討了(le)銅鋁(lv)(lv)(lv)層狀(zhuang)(zhuang)復(fu)合(he)(he)材料的(de)(de)(de)腐(fu)(fu)(fu)蝕(shi)(shi)行為(wei)(wei)。通過(guo)掃描(miao)電(dian)鏡 （SEM） 觀察腐(fu)(fu)(fu)蝕(shi)(shi)后銅鋁(lv)(lv)(lv)界(jie)(jie)(jie)面(mian)形(xing)貌，結(jie)(jie)合(he)(he)X射線衍射儀 （XRD） 和能譜儀 （EDS） 分(fen)析腐(fu)(fu)(fu)蝕(shi)(shi)產(chan)物成分(fen)，并通過(guo)電(dian)化(hua)學檢測分(fen)析試樣經過(guo)不同時(shi)間鹽霧(wu)腐(fu)(fu)(fu)蝕(shi)(shi)后的(de)(de)(de)表面(mian)腐(fu)(fu)(fu)蝕(shi)(shi)狀(zhuang)(zhuang)態，探(tan)討銅鋁(lv)(lv)(lv)復(fu)合(he)(he)板(ban)在(zai)(zai)服役環(huan)境下的(de)(de)(de)腐(fu)(fu)(fu)蝕(shi)(shi)機制。結(jie)(jie)果表明(ming)：銅鋁(lv)(lv)(lv)復(fu)合(he)(he)板(ban)在(zai)(zai)鹽霧(wu)環(huan)境下銅鋁(lv)(lv)(lv)構成腐(fu)(fu)(fu)蝕(shi)(shi)原電(dian)池，Al為(wei)(wei)陽(yang)極(ji)銅為(wei)(wei)陰(yin)極(ji)，陰(yin)陽(yang)極(ji)面(mian)積比(bi)越大(da)(da)，腐(fu)(fu)(fu)蝕(shi)(shi)速率越大(da)(da)。隨著腐(fu)(fu)(fu)蝕(shi)(shi)的(de)(de)(de)不斷進(jin)行，銅鋁(lv)(lv)(lv)界(jie)(jie)(jie)面(mian)的(de)(de)(de)Cu一(yi)側發生腐(fu)(fu)(fu)蝕(shi)(shi)，且靠近(jin)界(jie)(jie)(jie)面(mian)的(de)(de)(de)位置(zhi)腐(fu)(fu)(fu)蝕(shi)(shi)最為(wei)(wei)嚴重(zhong)，隨著腐(fu)(fu)(fu)蝕(shi)(shi)時(shi)間延長，鋁(lv)(lv)(lv)基(ji)體(ti)出現嚴重(zhong)的(de)(de)(de)剝蝕(shi)(shi)現象，Cu幾乎無變化(hua)。腐(fu)(fu)(fu)蝕(shi)(shi)產(chan)物成分(fen)為(wei)(wei)Al2O3，Al（OH）3和AlO（OH），電(dian)化(hua)學結(jie)(jie)果顯示：銅鋁(lv)(lv)(lv)復(fu)合(he)(he)板(ban)在(zai)(zai)腐(fu)(fu)(fu)蝕(shi)(shi)的(de)(de)(de)過(guo)程(cheng)中(zhong)，腐(fu)(fu)(fu)蝕(shi)(shi)速率呈現先增加后減小再增加的(de)(de)(de)趨勢(shi)。

關(guan)鍵詞(ci)： 銅鋁層(ceng)狀復合板； 鹽霧(wu)腐(fu)蝕(shi)； 電化學； 失重； 腐(fu)蝕(shi)產物

銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)復(fu)(fu)合(he)(he)(he)(he)(he)板(ban)材(cai)作(zuo)(zuo)為(wei)一(yi)種(zhong)(zhong)新型(xing)復(fu)(fu)合(he)(he)(he)(he)(he)材(cai)料(liao)，兼具(ju)(ju)(ju)了(le)(le)鋁(lv)(lv)的(de)(de)(de)(de)(de)(de)質輕、經濟和銅(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)接觸電(dian)(dian)(dian)(dian)(dian)(dian)阻低、外(wai)表(biao)(biao)(biao)美觀(guan)、導電(dian)(dian)(dian)(dian)(dian)(dian)性(xing)好、導熱率(lv)高等優點，其(qi)(qi)廣(guang)泛(fan)應(ying)用(yong)(yong)于汽(qi)車、電(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)、電(dian)(dian)(dian)(dian)(dian)(dian)力(li)、電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)、石(shi)油(you)、化(hua)(hua)(hua)工、造船、冶金(jin)(jin)(jin)、機械、航空航天、生(sheng)活(huo)用(yong)(yong)具(ju)(ju)(ju)、原子(zi)(zi)能等工業領域(yu)[1-3]。銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)復(fu)(fu)合(he)(he)(he)(he)(he)板(ban)長期(qi)服役于大氣環境中(zhong)(zhong)(zhong)，發(fa)(fa)(fa)(fa)生(sheng)的(de)(de)(de)(de)(de)(de)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)類型(xing)常常具(ju)(ju)(ju)有多樣性(xing)，由(you)于不同(tong)的(de)(de)(de)(de)(de)(de)材(cai)料(liao)之間(jian)(jian)會(hui)形成(cheng)(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)偶對(dui)，且(qie)在腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)過程中(zhong)(zhong)(zhong)往往還會(hui)受到介質中(zhong)(zhong)(zhong)侵蝕(shi)(shi)(shi)(shi)性(xing)離子(zi)(zi)的(de)(de)(de)(de)(de)(de)作(zuo)(zuo)用(yong)(yong)，因此其(qi)(qi)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)機理相(xiang)對(dui)復(fu)(fu)雜(za)，其(qi)(qi)中(zhong)(zhong)(zhong)常見涉及的(de)(de)(de)(de)(de)(de)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)類型(xing)包括(kuo)電(dian)(dian)(dian)(dian)(dian)(dian)偶腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)、點蝕(shi)(shi)(shi)(shi)、縫隙腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)、全面腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)、化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)及電(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)(hua)學(xue)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)等[4-6]，而(er)且(qie)表(biao)(biao)(biao)面往往具(ju)(ju)(ju)有鈍化(hua)(hua)(hua)膜，對(dui)其(qi)(qi)具(ju)(ju)(ju)有保(bao)護作(zuo)(zuo)用(yong)(yong)，但表(biao)(biao)(biao)面常常存在局部(bu)缺陷，當(dang)存在破壞(huai)鈍化(hua)(hua)(hua)膜的(de)(de)(de)(de)(de)(de)活(huo)性(xing)離子(zi)(zi) （主要(yao)是鹵素原子(zi)(zi)Cl，F，Br，I，At） 與配位(wei)體(ti)(ti) （水(shui)中(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)(de)OH-） 時，容易造成(cheng)(cheng)鈍化(hua)(hua)(hua)膜的(de)(de)(de)(de)(de)(de)局部(bu)破壞(huai)，隨著(zhu)服役時間(jian)(jian)的(de)(de)(de)(de)(de)(de)延長，銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)材(cai)料(liao)遭受很(hen)強的(de)(de)(de)(de)(de)(de)破壞(huai)作(zuo)(zuo)用(yong)(yong)[7-9]。此外(wai)，銅(tong)(tong)(tong)(tong)(tong)(tong)板(ban)和鋁(lv)(lv)板(ban)結合(he)(he)(he)(he)(he)的(de)(de)(de)(de)(de)(de)界(jie)(jie)面處在制備過程中(zhong)(zhong)(zhong)由(you)于元素之間(jian)(jian)的(de)(de)(de)(de)(de)(de)擴散作(zuo)(zuo)用(yong)(yong)，形成(cheng)(cheng)了(le)(le)金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)，這些(xie)金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)對(dui)復(fu)(fu)合(he)(he)(he)(he)(he)板(ban)的(de)(de)(de)(de)(de)(de)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)具(ju)(ju)(ju)有一(yi)定的(de)(de)(de)(de)(de)(de)影響作(zuo)(zuo)用(yong)(yong)。研(yan)究(jiu)表(biao)(biao)(biao)明，在銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)界(jie)(jie)面處存在著(zhu)多種(zhong)(zhong)金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)，例(li)如CuAl、CuAl2、CuAl4和Cu9Al4，這些(xie)金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)雖然會(hui)增強異種(zhong)(zhong)金(jin)(jin)(jin)屬(shu)(shu)的(de)(de)(de)(de)(de)(de)結合(he)(he)(he)(he)(he)力(li)，但同(tong)時會(hui)削弱材(cai)料(liao)的(de)(de)(de)(de)(de)(de)力(li)學(xue)性(xing)能[10-12]。馮立臣(chen)等[13]認(ren)為(wei)在金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)層邊(bian)緣容易產(chan)(chan)生(sheng)應(ying)力(li)集中(zhong)(zhong)(zhong)，從而(er)萌生(sheng)裂(lie)紋源，通(tong)過腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)離子(zi)(zi)的(de)(de)(de)(de)(de)(de)侵蝕(shi)(shi)(shi)(shi)加(jia)速腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)發(fa)(fa)(fa)(fa)生(sheng)。殷祚炷等[14]卻發(fa)(fa)(fa)(fa)現(xian)銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)釬焊接頭中(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)(de)金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)是高電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)陰極(ji)相(xiang)，不易發(fa)(fa)(fa)(fa)生(sheng)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)。尤其(qi)(qi)當(dang)銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)之間(jian)(jian)構成(cheng)(cheng)了(le)(le)電(dian)(dian)(dian)(dian)(dian)(dian)偶對(dui)，產(chan)(chan)生(sheng)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)偶腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)對(dui)其(qi)(qi)他腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)類型(xing)也具(ju)(ju)(ju)有一(yi)定的(de)(de)(de)(de)(de)(de)促進(jin)作(zuo)(zuo)用(yong)(yong)。趙巖等[15]認(ren)為(wei)覆銅(tong)(tong)(tong)(tong)(tong)(tong)板(ban) （CCL） 比純(chun)銅(tong)(tong)(tong)(tong)(tong)(tong)耐蝕(shi)(shi)(shi)(shi)性(xing)能差，因為(wei)發(fa)(fa)(fa)(fa)生(sheng)了(le)(le)電(dian)(dian)(dian)(dian)(dian)(dian)偶腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)。陳國宏等[16]研(yan)究(jiu)了(le)(le)220 kV變電(dian)(dian)(dian)(dian)(dian)(dian)站銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)過渡線夾腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)與斷裂(lie)的(de)(de)(de)(de)(de)(de)問(wen)題，研(yan)究(jiu)認(ren)為(wei)銅(tong)(tong)(tong)(tong)(tong)(tong)鋁(lv)(lv)過渡線夾底(di)部(bu)產(chan)(chan)生(sheng)的(de)(de)(de)(de)(de)(de)焊縫腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)產(chan)(chan)物(wu)(wu)(wu)是由(you)于Cu、Al兩種(zhong)(zhong)金(jin)(jin)(jin)屬(shu)(shu)之間(jian)(jian)發(fa)(fa)(fa)(fa)生(sheng)了(le)(le)電(dian)(dian)(dian)(dian)(dian)(dian)化(hua)(hua)(hua)學(xue)反應(ying)，從而(er)形成(cheng)(cheng)了(le)(le)以(yi)鋁(lv)(lv)為(wei)負極(ji)、銅(tong)(tong)(tong)(tong)(tong)(tong)為(wei)正極(ji)的(de)(de)(de)(de)(de)(de)原電(dian)(dian)(dian)(dian)(dian)(dian)池，加(jia)速鋁(lv)(lv)發(fa)(fa)(fa)(fa)生(sheng)縫隙腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)。Davovdi等[17,18]將AFM和SECM相(xiang)結合(he)(he)(he)(he)(he)觀(guan)察了(le)(le)鋁(lv)(lv)合(he)(he)(he)(he)(he)金(jin)(jin)(jin)在NaCl溶液中(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)(de)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)行為(wei)，發(fa)(fa)(fa)(fa)現(xian)鋁(lv)(lv)合(he)(he)(he)(he)(he)金(jin)(jin)(jin)最初發(fa)(fa)(fa)(fa)生(sheng)的(de)(de)(de)(de)(de)(de)點蝕(shi)(shi)(shi)(shi)是因為(wei)基體(ti)(ti)中(zhong)(zhong)(zhong)陽極(ji)性(xing)金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)的(de)(de)(de)(de)(de)(de)優先(xian)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)或與金(jin)(jin)(jin)屬(shu)(shu)間(jian)(jian)化(hua)(hua)(hua)合(he)(he)(he)(he)(he)物(wu)(wu)(wu)鄰近局域(yu)的(de)(de)(de)(de)(de)(de)金(jin)(jin)(jin)屬(shu)(shu)本(ben)體(ti)(ti)的(de)(de)(de)(de)(de)(de)腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)造成(cheng)(cheng)的(de)(de)(de)(de)(de)(de)，隨著(zhu)逐漸上升(sheng)的(de)(de)(de)(de)(de)(de)陽極(ji)電(dian)(dian)(dian)(dian)(dian)(dian)極(ji)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)，腐(fu)(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)進(jin)一(yi)步加(jia)深(shen)。

大(da)氣暴露腐(fu)(fu)(fu)蝕(shi)實驗是研(yan)究大(da)氣腐(fu)(fu)(fu)蝕(shi)最精確、最可靠(kao)的(de)(de)方法(fa)，但區域性強、實驗周期長，實驗結(jie)(jie)果(guo)不利于廣泛推(tui)廣[19-22]。本文通(tong)過模(mo)擬大(da)氣腐(fu)(fu)(fu)蝕(shi)進(jin)行室內中(zhong)性鹽(yan)霧實驗以(yi)縮短實驗周期，來探討在氯離子的(de)(de)作用下(xia)不同陰陽(yang)極面積(ji)比的(de)(de)銅鋁復合板(ban)材腐(fu)(fu)(fu)蝕(shi)行為，判斷腐(fu)(fu)(fu)蝕(shi)對界面層結(jie)(jie)合的(de)(de)影(ying)響，進(jin)而獲得界面層腐(fu)(fu)(fu)蝕(shi)對結(jie)(jie)合失效的(de)(de)影(ying)響機制(zhi)，為以(yi)后得到腐(fu)(fu)(fu)蝕(shi)條件下(xia)的(de)(de)復合板(ban)服(fu)役條件約(yue)束標準奠(dian)定理論基礎。

1 實驗方(fang)法

實(shi)驗材料(liao)選(xuan)用(yong)(yong)銅(tong)鋁層狀(zhuang)復(fu)合(he)板(ban)材，將其加工成(cheng)20 mm×20 mm×6.6 m和(he)20 mm×20 mm×3 mm的(de)試(shi)(shi)樣(yang)，如(ru)圖1所示。兩(liang)板(ban)通過鑄軋工藝形成(cheng)冶(ye)金(jin)結(jie)合(he)，在(zai)界(jie)面(mian)處存在(zai)三(san)層擴(kuo)散層，成(cheng)分為(wei)(wei)AlCu、Al2Cu和(he)Al4Cu9。將銅(tong)鋁結(jie)合(he)界(jie)面(mian)用(yong)(yong)600號(hao)到2000號(hao)砂紙逐級打磨(mo)并(bing)(bing)拋光(guang)至表面(mian)光(guang)亮均勻(yun)，用(yong)(yong)酒精(jing)擦(ca)洗后(hou)吹干(gan)并(bing)(bing)放在(zai)干(gan)燥皿里(li)干(gan)燥48 h后(hou)，使用(yong)(yong)游標卡尺測量(liang)試(shi)(shi)樣(yang)實(shi)際尺寸，并(bing)(bing)用(yong)(yong)精(jing)度為(wei)(wei)0.001 mg的(de)電子(zi)天平稱稱量(liang)試(shi)(shi)樣(yang)原始質量(liang)記(ji)錄下來。

圖1   銅鋁(lv)復合(he)板結(jie)構圖

中性(xing)鹽(yan)(yan)霧腐(fu)(fu)(fu)蝕(shi)實驗按照GB 6458-86在DG-170211鹽(yan)(yan)霧腐(fu)(fu)(fu)蝕(shi)機上進(jin)(jin)行(xing)(xing)。用(yong)棉繩將試樣懸掛在鹽(yan)(yan)霧腐(fu)(fu)(fu)蝕(shi)箱工作室內(nei)，實驗溫(wen)度為(wei)35 ℃，選(xuan)取不同時(shi)間進(jin)(jin)行(xing)(xing)濃度為(wei)5% （質量(liang)分數） NaCl溶液的(de)連(lian)續鹽(yan)(yan)霧實驗，選(xuan)取鹽(yan)(yan)霧腐(fu)(fu)(fu)蝕(shi)時(shi)間分別為(wei)24，144和(he)240 h。鹽(yan)(yan)霧實驗后，刮下表(biao)面(mian)(mian)腐(fu)(fu)(fu)蝕(shi)產物及表(biao)面(mian)(mian)附著的(de)沉積鹽(yan)(yan)，酒精清洗吹(chui)干后，干燥48 h再進(jin)(jin)行(xing)(xing)稱重，最后進(jin)(jin)行(xing)(xing)相(xiang)關計算和(he)檢測。在VSP300電(dian)化學(xue)工作站進(jin)(jin)行(xing)(xing)電(dian)化學(xue)實驗，飽和(he)甘汞為(wei)參比電(dian)極，鉑絲為(wei)對電(dian)極，工作電(dian)極即銅鋁復(fu)合板使用(yong)熱熔膠將除了被測面(mian)(mian)以外均涂封好，被測面(mian)(mian)為(wei)銅鋁的(de)結合界面(mian)(mian)，極化曲線掃(sao)描范圍是-1~1 V，掃(sao)描速(su)度為(wei)10 mV/s，電(dian)化學(xue)阻(zu)抗頻率范圍為(wei)105~10-2 Hz，等效電(dian)路圖通過ZSIMPWIN軟件分析(xi)擬(ni)合，采用(yong)S-3400掃(sao)描電(dian)鏡 （SEM） 對銅鋁復(fu)合板表(biao)面(mian)(mian)及腐(fu)(fu)(fu)蝕(shi)產物進(jin)(jin)行(xing)(xing)微觀形貌及132-1D EDX能譜 （EDS） 分析(xi)成分，使用(yong)XRD-7000型X射線衍射儀 （XRD） 檢測腐(fu)(fu)(fu)蝕(shi)產物成分，掃(sao)描角度為(wei)10°~90°，掃(sao)描速(su)度為(wei)8°/min。腐(fu)(fu)(fu)蝕(shi)失(shi)重采用(yong)公式

計算得到，其中W1為(wei)腐(fu)蝕(shi)(shi)后重量(liang)(liang)，g，W0為(wei)腐(fu)蝕(shi)(shi)前重量(liang)(liang)，g，S為(wei)試(shi)樣暴(bao)露在鹽霧環境下的(de)面(mian)積，m2。

2 結果與分析(xi)

2.1 電化學(xue)檢測

為(wei)了研究陰(yin)(yin)(yin)(yin)陽(yang)(yang)極(ji)面(mian)(mian)積(ji)(ji)(ji)比(bi) （被測面(mian)(mian)上陰(yin)(yin)(yin)(yin)極(ji)銅(tong)(tong)面(mian)(mian)積(ji)(ji)(ji)與陽(yang)(yang)極(ji)鋁(lv)面(mian)(mian)積(ji)(ji)(ji)的(de)(de)(de)(de)(de)(de)比(bi)值） 對(dui)銅(tong)(tong)鋁(lv)復(fu)(fu)合板(ban)(ban)(ban)(ban)腐(fu)蝕(shi)(shi)(shi)(shi)(shi)性(xing)能的(de)(de)(de)(de)(de)(de)影響，將陰(yin)(yin)(yin)(yin)陽(yang)(yang)極(ji)面(mian)(mian)積(ji)(ji)(ji)比(bi)分別為(wei)0.16和(he)0.18的(de)(de)(de)(de)(de)(de)銅(tong)(tong)鋁(lv)復(fu)(fu)合板(ban)(ban)(ban)(ban)浸泡在NaCl溶液中進行電(dian)(dian)(dian)(dian)化(hua)學檢測，得(de)到極(ji)化(hua)曲線圖(tu)和(he)電(dian)(dian)(dian)(dian)化(hua)學阻抗譜。圖(tu)2為(wei)測得(de)的(de)(de)(de)(de)(de)(de)極(ji)化(hua)曲線圖(tu)，通過Tafel外推法計算(suan)得(de)出的(de)(de)(de)(de)(de)(de)自腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)流(liu)密(mi)(mi)(mi)度和(he)自腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)位(wei)如表(biao)1所(suo)示。自腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)流(liu)密(mi)(mi)(mi)度可以(yi)反(fan)映材料(liao)的(de)(de)(de)(de)(de)(de)耐腐(fu)蝕(shi)(shi)(shi)(shi)(shi)性(xing)能，自腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)流(liu)密(mi)(mi)(mi)度越大(da)，說(shuo)明材料(liao)的(de)(de)(de)(de)(de)(de)腐(fu)蝕(shi)(shi)(shi)(shi)(shi)速率越快，耐腐(fu)蝕(shi)(shi)(shi)(shi)(shi)性(xing)能越差。從表(biao)1中可以(yi)看(kan)出，陰(yin)(yin)(yin)(yin)陽(yang)(yang)極(ji)面(mian)(mian)積(ji)(ji)(ji)比(bi)為(wei)0.16的(de)(de)(de)(de)(de)(de)銅(tong)(tong)鋁(lv)復(fu)(fu)合板(ban)(ban)(ban)(ban)的(de)(de)(de)(de)(de)(de)腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)流(liu)密(mi)(mi)(mi)度為(wei)19.2 μA·cm-2，陰(yin)(yin)(yin)(yin)陽(yang)(yang)極(ji)面(mian)(mian)積(ji)(ji)(ji)比(bi)為(wei)0.18的(de)(de)(de)(de)(de)(de)銅(tong)(tong)鋁(lv)復(fu)(fu)合板(ban)(ban)(ban)(ban)的(de)(de)(de)(de)(de)(de)腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)流(liu)密(mi)(mi)(mi)度為(wei)36.8 μA·cm-2，而(er)純(chun)鋁(lv)的(de)(de)(de)(de)(de)(de)腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)流(liu)密(mi)(mi)(mi)度為(wei)1.852 μA·cm-2，銅(tong)(tong)鋁(lv)復(fu)(fu)合板(ban)(ban)(ban)(ban)構成(cheng)的(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)偶對(dui)降低(di)了鋁(lv)的(de)(de)(de)(de)(de)(de)耐蝕(shi)(shi)(shi)(shi)(shi)性(xing)能，隨(sui)著(zhu)陰(yin)(yin)(yin)(yin)陽(yang)(yang)極(ji)面(mian)(mian)積(ji)(ji)(ji)比(bi)的(de)(de)(de)(de)(de)(de)增大(da)，自腐(fu)蝕(shi)(shi)(shi)(shi)(shi)電(dian)(dian)(dian)(dian)流(liu)密(mi)(mi)(mi)度增大(da)，說(shuo)明銅(tong)(tong)鋁(lv)陰(yin)(yin)(yin)(yin)陽(yang)(yang)極(ji)面(mian)(mian)積(ji)(ji)(ji)比(bi)越大(da)，耐腐(fu)蝕(shi)(shi)(shi)(shi)(shi)性(xing)能變差。

圖(tu)2   不同陰陽極面積(ji)比的銅(tong)鋁(lv)復合板極化(hua)曲線

表(biao)1   極化曲線(xian)擬(ni)合數(shu)據

圖(tu)(tu)(tu)3為(wei)(wei)不同(tong)陰陽(yang)極(ji)(ji)(ji)(ji)面(mian)積(ji)比(bi)的(de)(de)(de)(de)銅鋁復(fu)(fu)合(he)板測得的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)化學阻(zu)(zu)抗(kang)譜，Nyquist圖(tu)(tu)(tu)均由一個容(rong)抗(kang)弧組成，bode圖(tu)(tu)(tu)中(zhong)的(de)(de)(de)(de)相(xiang)(xiang)位角圖(tu)(tu)(tu)顯示(shi)銅鋁復(fu)(fu)合(he)板為(wei)(wei)一個時間(jian)常(chang)數(shu)，而(er)純鋁為(wei)(wei)兩個時間(jian)常(chang)數(shu)，將電(dian)(dian)(dian)(dian)化學阻(zu)(zu)抗(kang)譜用(yong)ZSIMPWIN軟件擬合(he)成如圖(tu)(tu)(tu)4a和b所示(shi)的(de)(de)(de)(de)等效電(dian)(dian)(dian)(dian)路圖(tu)(tu)(tu)，擬合(he)數(shu)據(ju)如表(biao)2所示(shi)，其(qi)中(zhong)Rs為(wei)(wei)溶(rong)液電(dian)(dian)(dian)(dian)阻(zu)(zu)，電(dian)(dian)(dian)(dian)容(rong)用(yong)常(chang)相(xiang)(xiang)角元件代替，CPEdl代表(biao)工作電(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)表(biao)面(mian)的(de)(de)(de)(de)雙電(dian)(dian)(dian)(dian)層電(dian)(dian)(dian)(dian)容(rong)，Rb代表(biao)腐(fu)(fu)蝕(shi)產物層電(dian)(dian)(dian)(dian)阻(zu)(zu)，Rct代表(biao)工作電(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)表(biao)面(mian)反應的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)荷(he)(he)轉(zhuan)(zhuan)移電(dian)(dian)(dian)(dian)阻(zu)(zu)，電(dian)(dian)(dian)(dian)荷(he)(he)轉(zhuan)(zhuan)移電(dian)(dian)(dian)(dian)阻(zu)(zu)越小，說明材料的(de)(de)(de)(de)耐(nai)腐(fu)(fu)蝕(shi)性能(neng)(neng)越差(cha)。從表(biao)2中(zhong)擬合(he)的(de)(de)(de)(de)數(shu)據(ju)可以看出，陰陽(yang)極(ji)(ji)(ji)(ji)面(mian)積(ji)比(bi)為(wei)(wei)0.16的(de)(de)(de)(de)銅鋁復(fu)(fu)合(he)板的(de)(de)(de)(de)Rct為(wei)(wei)1421 Ω·cm2，陰陽(yang)極(ji)(ji)(ji)(ji)面(mian)積(ji)比(bi)為(wei)(wei)0.18的(de)(de)(de)(de)銅鋁復(fu)(fu)合(he)板Rct為(wei)(wei)219 Ω·cm2，說明隨著陰陽(yang)極(ji)(ji)(ji)(ji)面(mian)積(ji)比(bi)的(de)(de)(de)(de)增(zeng)大，工作電(dian)(dian)(dian)(dian)極(ji)(ji)(ji)(ji)表(biao)面(mian)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)荷(he)(he)轉(zhuan)(zhuan)移電(dian)(dian)(dian)(dian)阻(zu)(zu)減小，材料的(de)(de)(de)(de)耐(nai)腐(fu)(fu)蝕(shi)性能(neng)(neng)降低(di)(di)，純鋁電(dian)(dian)(dian)(dian)荷(he)(he)轉(zhuan)(zhuan)移電(dian)(dian)(dian)(dian)阻(zu)(zu)最(zui)(zui)大，該結果與極(ji)(ji)(ji)(ji)化曲線的(de)(de)(de)(de)結果相(xiang)(xiang)吻合(he)。從bode圖(tu)(tu)(tu)中(zhong)的(de)(de)(de)(de)阻(zu)(zu)抗(kang)曲線可以看出，純鋁的(de)(de)(de)(de)阻(zu)(zu)抗(kang)值最(zui)(zui)大，且增(zeng)大陰陽(yang)極(ji)(ji)(ji)(ji)面(mian)積(ji)比(bi)時阻(zu)(zu)抗(kang)值降低(di)(di)，也表(biao)明銅鋁復(fu)(fu)合(he)板的(de)(de)(de)(de)耐(nai)腐(fu)(fu)蝕(shi)性能(neng)(neng)降低(di)(di)。

圖3   不同(tong)陰陽極面積比的銅鋁復合板電化(hua)學阻(zu)抗譜

圖4   電化學阻抗等效電路圖

表2   電化學阻抗等效電路擬合(he)數(shu)據

圖5為經過(guo)不同時(shi)(shi)間鹽霧腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)后的(de)(de)(de)銅鋁復合(he)板極化(hua)(hua)曲線，相應的(de)(de)(de)擬合(he)數據(ju)如(ru)表(biao)(biao)3所(suo)示，從表(biao)(biao)中可以(yi)看出，隨著腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)時(shi)(shi)間的(de)(de)(de)延長，腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)電(dian)流密度(du)呈(cheng)現先增加后降低最后增加的(de)(de)(de)趨(qu)勢(shi)，這是因(yin)為在(zai)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)開始之(zhi)前，材(cai)料(liao)(liao)表(biao)(biao)面會覆蓋一層鈍化(hua)(hua)膜(mo)，保護基(ji)體(ti)免受腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)溶液的(de)(de)(de)侵蝕(shi)(shi)(shi)(shi)，此(ci)時(shi)(shi)材(cai)料(liao)(liao)的(de)(de)(de)耐(nai)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)(xing)能較好。當腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)發(fa)展到24 h時(shi)(shi)，材(cai)料(liao)(liao)表(biao)(biao)面的(de)(de)(de)氧化(hua)(hua)膜(mo)被腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)破(po)壞(huai)，裸露出來的(de)(de)(de)基(ji)體(ti)與(yu)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)液接觸面積增大，使得材(cai)料(liao)(liao)的(de)(de)(de)耐(nai)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)(xing)能變(bian)差。隨著腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)進行(xing)到144 h的(de)(de)(de)時(shi)(shi)候，材(cai)料(liao)(liao)表(biao)(biao)面生(sheng)成新的(de)(de)(de)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)產物覆蓋在(zai)基(ji)體(ti)表(biao)(biao)面，阻礙腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)溶液對基(ji)體(ti)的(de)(de)(de)進一步侵蝕(shi)(shi)(shi)(shi)，材(cai)料(liao)(liao)的(de)(de)(de)耐(nai)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)(xing)能提(ti)高。當腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)到達240 h時(shi)(shi)，由(you)于后生(sheng)成的(de)(de)(de)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)產物疏松多孔容易(yi)脫落，使得基(ji)體(ti)與(yu)溶液再(zai)(zai)一次接觸，試樣的(de)(de)(de)耐(nai)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)(xing)能再(zai)(zai)次降低。

圖5   鹽(yan)霧腐蝕不同時間(jian)后(hou)的銅鋁復合板極化曲線

表3   極(ji)化曲線(xian)擬合數據

圖(tu)6為(wei)經過(guo)不同鹽霧(wu)腐(fu)(fu)蝕(shi)(shi)(shi)時(shi)間后(hou)(hou)(hou)的(de)(de)銅(tong)鋁(lv)復(fu)合板(ban)電(dian)(dian)化學阻(zu)抗(kang)(kang)(kang)譜(pu)，從(cong)圖(tu)6a中(zhong)可(ke)以看出，阻(zu)抗(kang)(kang)(kang)譜(pu)均由一(yi)(yi)個容(rong)抗(kang)(kang)(kang)弧組成(cheng)，且(qie)容(rong)抗(kang)(kang)(kang)弧半徑隨(sui)著腐(fu)(fu)蝕(shi)(shi)(shi)時(shi)間的(de)(de)延長，呈現先減(jian)小(xiao)(xiao)再(zai)增(zeng)加(jia)最后(hou)(hou)(hou)減(jian)小(xiao)(xiao)的(de)(de)趨(qu)勢，說明(ming)材料的(de)(de)耐(nai)腐(fu)(fu)蝕(shi)(shi)(shi)性能(neng)隨(sui)著鹽霧(wu)腐(fu)(fu)蝕(shi)(shi)(shi)時(shi)間的(de)(de)增(zeng)加(jia)呈現先提高(gao)后(hou)(hou)(hou)降低再(zai)提高(gao)的(de)(de)趨(qu)勢。圖(tu)6b圖(tu)中(zhong)相位角(jiao)圖(tu)顯示為(wei)一(yi)(yi)個時(shi)間常數。通過(guo)ZSIMPWIN軟(ruan)件擬合出的(de)(de)等效電(dian)(dian)路(lu)圖(tu) （圖(tu)4） 數據如表(biao)4所(suo)示。從(cong)表(biao)4中(zhong)可(ke)以看出，沒經過(guo)鹽霧(wu)腐(fu)(fu)蝕(shi)(shi)(shi)的(de)(de)銅(tong)鋁(lv)復(fu)合板(ban)Rct為(wei)1.0×104 Ω·cm2，鹽霧(wu)腐(fu)(fu)蝕(shi)(shi)(shi)24 h后(hou)(hou)(hou)Rct降低到(dao)1.9×103 Ω·cm2，到(dao)144 h時(shi)Rct升高(gao)到(dao)7.6×103 Ω·cm2，當腐(fu)(fu)蝕(shi)(shi)(shi)發展(zhan)到(dao)240 h時(shi)，Rct再(zai)次降低到(dao)3.0×103 Ω·cm2。由此可(ke)以看出，隨(sui)著腐(fu)(fu)蝕(shi)(shi)(shi)時(shi)間的(de)(de)延長，電(dian)(dian)荷(he)轉移電(dian)(dian)阻(zu)均呈現先減(jian)小(xiao)(xiao)再(zai)增(zeng)加(jia)最后(hou)(hou)(hou)減(jian)小(xiao)(xiao)的(de)(de)趨(qu)勢，波特圖(tu)中(zhong)的(de)(de)阻(zu)抗(kang)(kang)(kang)值也是呈現先減(jian)小(xiao)(xiao)再(zai)增(zeng)加(jia)最后(hou)(hou)(hou)減(jian)小(xiao)(xiao)的(de)(de)趨(qu)勢，該結果(guo)(guo)與極化曲線的(de)(de)結果(guo)(guo)相吻(wen)合。

圖6   鹽霧腐蝕不同時間后的銅鋁(lv)復合(he)板電化學(xue)阻抗譜

表4   電(dian)化學阻抗等效電(dian)路擬合數據(ju)

2.2 腐蝕(shi)微觀形貌及(ji)腐蝕(shi)產(chan)物成分分析(xi)

經過不同時間鹽霧(wu)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)后的(de)(de)銅鋁界面(mian)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)微(wei)觀形貌如圖(tu)7所示，從圖(tu)中可(ke)以看(kan)出，腐(fu)(fu)(fu)(fu)蝕(shi)(shi)集中在Al一(yi)(yi)側，Cu一(yi)(yi)側幾(ji)乎無變(bian)(bian)化(hua)，且在界面(mian)處(chu)的(de)(de)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)最(zui)為(wei)嚴重。腐(fu)(fu)(fu)(fu)蝕(shi)(shi)24 h時 （圖(tu)7b），在鋁一(yi)(yi)側出現寬度均(jun)勻、接近(jin)500 μm的(de)(de)狹(xia)長腐(fu)(fu)(fu)(fu)蝕(shi)(shi)坑，腐(fu)(fu)(fu)(fu)蝕(shi)(shi)坑處(chu)被(bei)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)的(de)(de)基體呈現蜂窩(wo)狀，在鋁一(yi)(yi)側沿著銅鋁界面(mian)處(chu)分(fen)布著較為(wei)致(zhi)密的(de)(de)白色塊狀腐(fu)(fu)(fu)(fu)蝕(shi)(shi)產物；腐(fu)(fu)(fu)(fu)蝕(shi)(shi)144 h時腐(fu)(fu)(fu)(fu)蝕(shi)(shi)坑面(mian)積變(bian)(bian)大，從圖(tu)中可(ke)以看(kan)到腐(fu)(fu)(fu)(fu)蝕(shi)(shi)坑內(nei)開(kai)始生(sheng)(sheng)成新的(de)(de)龜裂狀腐(fu)(fu)(fu)(fu)蝕(shi)(shi)產物；腐(fu)(fu)(fu)(fu)蝕(shi)(shi)到達240 h時，鋁基體剝蝕(shi)(shi)現象顯(xian)著，腐(fu)(fu)(fu)(fu)蝕(shi)(shi)產物脫(tuo)落現象明顯(xian)，裸露出的(de)(de)鋁基體面(mian)積更大。圖(tu)8為(wei)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)產物的(de)(de)成分(fen)分(fen)析(xi)，其中圖(tu)8a是(shi)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)產物XRD檢測結果，結果顯(xian)示腐(fu)(fu)(fu)(fu)蝕(shi)(shi)產物的(de)(de)成分(fen)為(wei)Al2O3，AlO（OH） 和Al（OH）3。從圖(tu)8b的(de)(de)能譜分(fen)析(xi)上可(ke)以看(kan)出，腐(fu)(fu)(fu)(fu)蝕(shi)(shi)坑內(nei)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)產物的(de)(de)元素(su)除了(le)有Al和O之外，還有一(yi)(yi)定含量的(de)(de)Cl，說(shuo)明Cl-是(shi)致(zhi)使銅鋁復合板發生(sheng)(sheng)腐(fu)(fu)(fu)(fu)蝕(shi)(shi)的(de)(de)主要(yao)因素(su)。

圖(tu)7   不(bu)同鹽霧腐(fu)蝕時間銅(tong)鋁(lv)復(fu)合板界面形貌(mao)圖(tu)

圖(tu)8   腐蝕產物的XRD譜及EDS分析

2.3 腐(fu)蝕動力學

圖9為銅(tong)鋁復合板在5%NaCl鹽(yan)霧環(huan)境下進行不同時(shi)間連續腐(fu)(fu)蝕(shi)的動(dong)力(li)學(xue)曲線(xian)，通過(guo)(guo)origin軟(ruan)件擬(ni)合得(de)到(dao)的曲線(xian)方程(cheng)如圖中所示，其中R2=0.9962，說明擬(ni)合效果良好(hao)。擬(ni)合的方程(cheng)呈(cheng)現冪指數形式：W=abn，其中n的大小(xiao)代表腐(fu)(fu)蝕(shi)產(chan)物(wu)對腐(fu)(fu)蝕(shi)的影響，當(dang)n＜1時(shi)，說明腐(fu)(fu)蝕(shi)產(chan)物(wu)對腐(fu)(fu)蝕(shi)過(guo)(guo)程(cheng)具有抑制作用(yong)；當(dang)n＞1時(shi)，說明腐(fu)(fu)蝕(shi)產(chan)物(wu)對腐(fu)(fu)蝕(shi)過(guo)(guo)程(cheng)具有促進作用(yong)。銅(tong)鋁復合板鹽(yan)霧腐(fu)(fu)蝕(shi)得(de)到(dao)的腐(fu)(fu)蝕(shi)動(dong)力(li)學(xue)方程(cheng)中n值為1.55359，大于1，說明腐(fu)(fu)蝕(shi)產(chan)物(wu)對銅(tong)鋁復合板的腐(fu)(fu)蝕(shi)具有促進作用(yong)。

圖9   鹽霧環境(jing)下的腐(fu)蝕動力(li)學曲線

2.4 銅(tong)鋁復合(he)板(ban)鹽霧腐蝕機(ji)理

圖(tu)10是銅(tong)鋁復合(he)板鹽霧腐(fu)蝕(shi)示意圖(tu)，當Cu和Al復合(he)在一起時(shi)，兩(liang)種金屬的(de)電(dian)位差構(gou)成電(dian)偶對(dui)，Cu的(de)電(dian)位高于Al的(de)電(dian)位，所(suo)以腐(fu)蝕(shi)的(de)過(guo)程中(zhong)鋁為陽極，Cu為陰(yin)極，因此(ci)Al的(de)腐(fu)蝕(shi)較為嚴(yan)重，而(er)Cu側幾乎不腐(fu)蝕(shi)，這是對(dui)陰(yin)極Cu的(de)一種保護作用。腐(fu)蝕(shi)過(guo)程中(zhong)涉及的(de)電(dian)化學反應方程式(shi)有：

圖(tu)(tu)10   銅鋁復(fu)合板(ban)鹽霧腐蝕示(shi)意(yi)圖(tu)(tu)

在腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)剛開始階段(duan)，由于金(jin)屬(shu)表(biao)面覆蓋一(yi)層(ceng)致密的(de)鈍化膜(mo)，保(bao)護基(ji)(ji)(ji)體(ti)免受腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)性(xing)溶液的(de)侵蝕(shi)(shi)(shi)(shi)，腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)速率較慢；隨(sui)著腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)時間(jian)逐(zhu)漸延(yan)長，由于侵蝕(shi)(shi)(shi)(shi)性(xing)離子Cl-的(de)存在，使得鈍化膜(mo)破壞，基(ji)(ji)(ji)體(ti)與(yu)溶液相接(jie)觸(chu)(chu)，腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)速率加快，鋁(lv)(lv)基(ji)(ji)(ji)體(ti)上出現(xian)點(dian)蝕(shi)(shi)(shi)(shi)坑(keng)并產生新的(de)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)產物，且靠近(jin)(jin)銅(tong)鋁(lv)(lv)界(jie)面處的(de)Al腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)較為嚴(yan)重(zhong)；腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)逐(zhu)步(bu)進行的(de)過(guo)程(cheng)中，鋁(lv)(lv)基(ji)(ji)(ji)體(ti)上小的(de)點(dian)蝕(shi)(shi)(shi)(shi)坑(keng)逐(zhu)漸擴展(zhan)，銅(tong)鋁(lv)(lv)界(jie)面附近(jin)(jin)多(duo)個(ge)蝕(shi)(shi)(shi)(shi)坑(keng)連通形成更大(da)更深(shen)的(de)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)坑(keng)，腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)產物增多(duo)，除(chu)了(le)塊狀之外還(huan)有(you)龜(gui)裂狀的(de)腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)產物，阻礙基(ji)(ji)(ji)體(ti)與(yu)Cl-的(de)接(jie)觸(chu)(chu)，腐(fu)(fu)(fu)(fu)(fu)蝕(shi)(shi)(shi)(shi)速率變慢，此(ci)時涉及(ji)的(de)反應方程(cheng)式有(you)：

其中AlOOH對基(ji)體具有很(hen)強的(de)保護作(zuo)用(yong)；腐(fu)蝕(shi)后期由于(yu)后來逐(zhu)漸形成疏松(song)多孔(kong)易(yi)于(yu)脫落(luo)的(de)腐(fu)蝕(shi)產物，與Cl-反應溶(rong)解，使(shi)得(de)基(ji)體再次裸(luo)露在(zai)外面(mian)，與溶(rong)液接觸面(mian)積增(zeng)大，腐(fu)蝕(shi)速率提高，此(ci)時涉及(ji)的(de)反應方程式有：

因此腐蝕過(guo)程是(shi)一(yi)個循環(huan)往復的過(guo)程，直到鋁基(ji)體(ti)被(bei)逐漸剝蝕掉。

3 結論

（1） 銅鋁復合板在(zai)腐(fu)(fu)(fu)蝕(shi)過(guo)程中構成電(dian)偶對加速(su)了Al的腐(fu)(fu)(fu)蝕(shi)，銅鋁復合板經過(guo)鹽霧腐(fu)(fu)(fu)蝕(shi)后，腐(fu)(fu)(fu)蝕(shi)主要發生在(zai)Al一(yi)側，Cu側幾乎無(wu)變(bian)化(hua)；且隨著銅鋁陰陽極面積比的增大，材料的耐腐(fu)(fu)(fu)蝕(shi)性能變(bian)差。

（2） 由于銅鋁復合板的腐蝕是一個循環往復的過程(cheng)，包括基(ji)體的溶解、腐蝕產物的形(xing)成與脫(tuo)落過程(cheng)；隨(sui)著(zhu)鹽霧腐蝕時間逐漸延長，電化學檢(jian)測(ce)結果表明(ming)銅鋁復合板的耐腐蝕性能(neng)呈現先提(ti)高后降低再提(ti)高的趨勢。

（3） 銅(tong)鋁復(fu)合板失(shi)重(zhong)曲線符合冪(mi)指(zhi)數(shu)方(fang)程W=1.948×10-5t3.17156，腐(fu)蝕(shi)產(chan)物(wu)對腐(fu)蝕(shi)過程具有促進(jin)作用。腐(fu)蝕(shi)產(chan)物(wu)成分(fen)為Al2O3、AlO（OH） 和(he)Al（OH）3，Cl-使得(de)材料發生(sheng)點蝕(shi)，在靠近界面處，鋁基體(ti)發生(sheng)腐(fu)蝕(shi)最為嚴重(zhong)；隨后(hou)腐(fu)蝕(shi)坑進(jin)一步向橫(heng)向和(he)縱向擴展，腐(fu)蝕(shi)產(chan)物(wu)逐漸增多，再與(yu)Cl-反應而脫(tuo)落反復(fu)循環進(jin)行。