( 1. 北京科技大學(xué) 材料科學(xué)與工程學(xué)院 腐蝕與防護(hù)中心,
北京 100083；
2. 中國科學(xué)院 金屬研究所 金屬腐蝕與防護(hù)國家重點(diǎn)實(shí)驗(yàn)室, 沈陽 110016)
摘 要: 采用X射線光電子能譜（XPS）對鉛錫合金表面鈍化層的組分與結(jié)構(gòu)進(jìn)行分析，目的是要確定鈍化層中各元素的化學(xué)價(jià)態(tài)和存在形式， 并試圖明確錫對鈍化膜導(dǎo)電能力的影響。 結(jié)果表明： 鈍化膜具有分層結(jié)構(gòu)， 表層由SnO2， SnO， PbSO4， PbOx（1<x<2）和PbOx·Sn1-xO2組成，內(nèi)層為SnO2， SnO， PbO， PbOx和PbOx·Sn1-xO2。內(nèi)層鈍化膜的導(dǎo)電性優(yōu)于表層， 錫能促進(jìn)生成電阻遠(yuǎn)小于PbSO4和PbO的鉛的過渡氧化物PbOx（1<x<2）， 從而提高其電導(dǎo)率。但是， 內(nèi)層的物質(zhì)構(gòu)成和分布并不均勻， 出現(xiàn)了非導(dǎo)電區(qū)（極少量）和導(dǎo)電區(qū)并存的現(xiàn)象， 而外層并沒有類似情況發(fā)生。 鈍化膜自外向內(nèi)含鉛量和含錫量均呈上升趨勢， 含氧量呈下降趨勢，錫的增值幅度隨母體含錫量的減少而增大， 但鉛濃度的變化規(guī)律與之相反。
關(guān)鍵字: 鉛錫合金; 鈍化膜; XPS
WANG Ze-li1, DONG Chao-fang1
（ 1. Corrosion and Protection Center, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. The State Key Laboratory of Metals Corrosion and Protection,
Metal Research Institute, Chinese Academy of Sciences, Shenyang 110016, China）
Abstract: The composition and structure of the passive film on Pb-Sn alloys were studied by X-ray photo electron spectroscopy(XPS) in order to determine the chemical valence number and existing state of alloying elements in passive layers and to elucidate the effect of Sn content on the electronic conductivity of the passive layers. It is found that the passive film has two-layered structure with SnO2, SnO, PbSO4, PbOx(1<x<2) and PbOx·Sn1-xO2 in outer layer, and SnO2, SnO, PbO, PbOx and PbOx·Sn1-xO2 in inner layer. Sn can improve the formation of PbOx(1＜x＜2) which results in the increase of conductivity of the passive film. From outer layer to inner one, the contents of Sn and Pb increase and O content decreases.
Key words: lead-tin alloy; passive layer; XPS
