Ce(NO 3 ) g/l KMnO g/l HF 2 ph ÓÞ

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1 Û Û 1 Ƴ Vol. No.1 01 Õ Journal of Chinese Society for Corrosion and Protection Feb. 01 É Â Ce-Mn ß Ï ÕÝ HF Ç ÐÖ ÈÐÄ Đ ( ß ½Ì Ç Ò À ) Ù Ó : Ã Ü EPMA«X»» XRD«ÅÆ EDS«X» Å XPS«Ce-Mn ÖÖ ¾ Ð ÐÐÍ ¹ à ÐÀ ÚÕ É Ô HF ß Ce-Mn Ö ÃÕ ÐÍ F Ce-Mn Ö Õ ÃÃ Ö Õ½ ËÇ Ë Õ² ÐÆ Ð Ö (Al O ) Õ ÍÞ Ï ¼ÃÕ [AlF 6] ²Éµ 1.8 mmol/l Ù Ã : HF Ce-Mn Ö [AlF 6] À Ü Æ : TG174.4 º Ë : A Ú¹ : « Ñ Mansfeld [1] Â Ø ÔÓ½Ý Ô ÓÕ Ç Ó ÕÔ ¹ÃÑ [ 7] ÂÕ È Ä Ó ² [8 1] ÆÝÑ Ó + Ôµ [1 14] غ ÈÖ Äºµ ÂÕ ÎÂÕÔ È ÃÑ [15 18] ÂÕ Ô Ú Đ ÎÂÕÔ ËÌ µ ØÕ [16] «ÔÓÊÇ Ce(NO ) Þ KMnO 4 Þ Í HF Þ ÔÂÕ³ ³Ø 606 ÔÓÊÍ Ce-Mn Ôµ Õ º È Ø ÂÕ È µå ÂÕÎ Õ Đ Ê µòß Û (SEM) ÆÆ º È Æ ÕÁ ØÀ»Â Ð Â ÓÕÔÖ ² Ü Al Ce Mn Ô Õ Å»Â Ö «Ô Õ HF Ôµ ÊÆ Ù ¹ Ï È Ê Ce-Mn Ó Õ ³ Õ Ô» ½ ³ Æ Ì³Â ¹Õ Â Ð Ô ³Â ĺ HF Ôµ ÊÆ Ù : à : Ô¼ ÝÑ ±Ü (008Z01) Á ±Ø ±Ü (009A080500) Û Á : Á ÆÐÆ1964 ¾Æ ÂƵ ¾Ð Æ» ³ ¾Í Û : Á ÆE mail mewfli@scut.edu.cn Ò À ¼ËÞÛ Ô 606  mass%åþ Fe 0.5, Mg , Si , Cu , Mn Þ Al À É ĐØ É Þ 60 Ô 50 g/l NaOH ² É» ÂÂ Þ 7.5 g/l Ce(NO ) +1.5 g/l KMnO g/l HF ph ÓÞ. À Ø Â ² 7 min ½Å Å À Ç Å Õ Â µ ÅÆÍ Ð ÐÊ É»  ٠ÒÅ LEO-150 ¹ÆºµÒß Û (SEM) ¹ ÔĐ Å (EDS) ½Û» Â Æ EPMA-1600 ¹ß Ð Û ÆÅ (EPMA) ÆÕ Ì Å THERMOVG ÊÔ ESCALAB50X º ß Đ Å (XPS) Æ Õ Ô Ì³Â Philips X pert MPD Pro ¹ X º º Å (XRD) Õ Ô³¹ ½ Æ ÒÀ.1 ÞÎ SEM Ì EDS Ò 1 Þ È Ce-Mn ÕÕ ÔÛ» Ò a Þ ÎÒ 1a Õ ÂÛ Å Ì EDS Ò Ò b ÞÕ Ì EDS Ò EDS È Õ Al Ce O Mn

2 M%8e d6 40 Fig.1 Surface morphologies of convertion coating treated in the Ce+ -MnO 4 solution and HF ions are included. (a) morphologies of irregular particles; (b) high magnification Fig. EDS analysis of surface conversion coating treated in the the Ce+ -MnO 4 solution and HF ions are included. (a) elements distribution of the irregular particles for Fig.1a; (b) elements distribution of the surface morphologies for Fig.1b sk T 'J e ^r e J Fe Cu Mg Z Si p UPo 1 Al Ce O Mn pm" o z [18] p> - P Ce-Mn hq H\ Al Ce Mn pe h (q V E h ) 'J = O Al O Al(OH) Ce O /CeO Z/q E h MnO q MnO m"'jp L Al m"^, d, dp Al V A $ r 0 q ata r e p L h (% AlFeSiMn β-alfesi) Bh e ^r e = J NW pt y x V Ce pg x I^ # oq :* J w :M p/j C \a 1 / ph 1? Ce pe h Z E h [ t 1 //J C hq * 5 r/ Y Bdp P \ n b q:#k H\ Al Ce O Mn kt'j F k TU n \ zq:#kv Al sp kt)n P = O 9 U q :+xk T H^ Ce O Z Mn U F kt q:#k C ktvl a> -\. V1GUt_9/ n 4 C q : 4 k T A k p, n = Ce Mn Z O k T A q : k ^ % p" h B ^ Ce d Si O 1s Mn p Z C 1s Mg Ce 4d Cu Intensity/a.u. Fe [19] 0 [0] Binding energy /ev Fig. XPS survey spectrum of conversion coating treated in the Ce+ -MnO 4 solution and HF ions are included i # z 1 ' k7 bm! kte *k #& II i L F k T t k o " h \at III i ~= J q :p Al Ce O Mn k T a t f \ O ^ II iv L a q :p \ t (o z mm mm)! Vzq :p s # k III iu p 4 k T B = C II i III Al

3 1 À Ø : Ce-Mn Ö Ã HF Ú º 41 (b) Matrix (I) Coating (II) Resin (III) Ce Mn Al F O Distance/mm Fig.4 Elements distribution map by line scan of cross section for rare earth conversion coatings in the Ce + - MnO 4 solution with HF ions (a) cross section morphology, (b) line scan map / o Coating Matrix / o Fig.5 XRD spectra of conversion matrix and coating treated in the Ce + -MnO 4 solution and HF ions are included / o Al CeO MnO K x MnO 4 Fig.6 XRD analysis for sedimentation treated in the Ce + -MnO 4 solution and HF ions are included Õ ØØ Õ Ô ²Ç À Ô ÔÏ F Ì ÍÈ Ú Ö» Ñ Õ ¹ ¼Ë 606 ³ Í F Ö Õ Í F. ν ÞÔ¾ XRD Ò 5 Õ XRD Ò Ç Í Ø θ Þ 10 5 Ý Í Ð ÄÞ¹Ô ³ θ Ø Ý Í Ô Ä Al Ô Đ Õ ³  [16,18] ¹ È ³ Î Mn Ce Al Ô (Õ ÎÔ ) ÂÔµ ¾ ³ Ô Õ Ë ² ³ ر ɻ± ÛßÊ ß ± Ô ¼ ½Õ ÔÝ Ò 6 Â Ð Ô XRD Ò «Ð À Þ CeO MnO K x MnO ³Â ÙØ»ÙÊÆ» CeO MnO K x MnO Đ Î ÕÚ Â Ç ÙÎ Mn Ce (Õ Î ) ³Â ³ĐÍ Í Al F Ô «Ð Ù ³ÂÕ Ô ³Â Í F Á Í Al 4 Ê «¹ [16] Æ HF Ce- Mn ÕÂÕ ÔÓÔ Õ Ó Î ³ «Äº Õ ³ Â Ð Æ Ó Ø ÕÇ Ð Í Ì F Ë ²Ô F Î À Â Ø [1] Ç NaF µþâõ Ô Õ F ÍÈ Ñ 49.0% 54.7% F Ê ÕÔ»Â Þ [17] Ô ¹Æ ØÍ NaF Ô Â F Ó Ce + +F CeF (s) Î ½ Ü Ce- Mn Õ ½Õ ݱ Đ Ø Niu [] Ô ¹ Æ F Al μ AlF 6 ³ ²  ³Đ ÂÕ ¹ ÔÍ HF Ô Õ Â Ë ÔÓÔÕ Â Ð Í F HF Ôµ ÊÆ Þ± HF ¹Ø Ö ØÂ Ö Ô Õ (Al O )

4 4 ű»Â [AlF 6 ] ²  ³ Â Ô È K +  K AlF 6 ²³ 1 L Â Í F ±ÈÞ 10.8 mmol ¼Â K AlF 6 ±È Ê 10.8 mmol ÈÓÞ 0.46 g º ØÉ Ø ÓÞ 1.4 g/kg ³Đ Ñ Ë Ø Î ± Al O + 1HF + 6H+ [AlF 6 ] + H O + 1HF Al + 1HF + 6H+ [AlF 6 ] + H +1HF (1) () HF H + + F () Al + + 6F [AlF 6 ] (4) K + + [AlF 6 ] K AlF 6 (5) HF H + +F Ø Â H + Ó Í Ce-Mn Å ÂÔ ph É Đ ÑÒ˵ F Ê Al + Ô µ» ² ÂÔ Al + Đ Â Õ Ô¼ 5 ÀÊ (1) Í HF µþ Ce-Mn Õ ÂÔ Ì F Ce-Mn µ Õ Ô³Â ³ Õ Ô¼ ÊÆ () HF À Ê ¹µ ß Ö Â Ô Î Ö Ô± Õ (Al O ) Ô Ö Î ÌÝÜ Ö ÑÌÝ Ý µ Å Í Â Ce-Mn Õ Ö¼ Ô Æ Ce- Mn Õ Ö Ü Ü ÕÔ«¼Å [1] Mansfeld F, Wang V, Shih H. The Ce-Mo process for the development of a stainless aluminum [J]. Electrochem. Acta, 199, 7(1): 8-90 [] Mansfeld F. Surface modification of aluminum alloys in metal salts containing CeCl [J]. Solid Films, 1995, 70(1- ): [] Li J Q. Corrosion resistance of a conversion film formed on aluminium by tetravalent cerium salt [J]. Corros. Sci. Prot. Technol., 1996, 8(4): (Á¼. ±ÑË Þ [J]. Æ, 1996, 8(4): 71-75) [4] Wang C, Jiang F, Lin H C. The molybdate conversion coatings on LY1 aluminum alloy [J]. Rare Met. Mater. Eng., 00, (): 10-1 (ÚÄ,, ÏÌ. LY1» [J]. Å¾Í È, 00, (): 10-1) [5] Nordlien J H, Walmsley J C, Terberg H, et al. Formation of a zirconium-titanium based conversion layer on AA6060 aluminium [J]. Surf. Coat. Technol., 00, 15: 7-78 [6] Bethencourt M, Botana F J, Cano M J, et al. High protective environmental friendly and short-time developed conversion coatings for aluminium alloys[j]. Appl. Surf. Sci., 00, 189(1/): [7] Bethencourt M, Botana F J, Cano M J, et al. Advanced generation of green conversion coatings for aluminium alloys[j]. Appl. Surf. Sci., 004, 8: [8] Hinton B R W, Arnott D R, Ryan N E. The inhibition of aluminum corrosion by cerium cations [J]. Met. Forum, 1984, 7(4) : [9] Mansfeld F, Lin S, Kim K. Pitting and surface modifieation of SiC/Al[J]. Corros. Sci., 1987, 7: [10] Arnott D R, Ryan N E, Hinton B R W. Auger and XPS studies of cerium corrosion inhibition on 7075 aluminium alloy[j]. Appl. Surf. Sci., 1985, /: 6-51 [11] Hinton B R W. Cerium conversion coatings for corrosion protection of aluminum[j]. Mater. Forum, 1989, 9(): [1] Arnote D R. Cationic film forming inhibitors for the protection of AA7075 aluminum alloy chloride against corrosion in aqueous chloride solution [J]. Corros. Sci., 1989, 45(1): 1-19 [1] Mansfeld F, Wang V, Shih H. Development of stainless aluminum [J]. J. Electrochem. Soc., 1991,18(1): L74- L75 [14] Mansfeld F, Wang V, Shih H. The Ce-Mo proeess for the development of a starriness aluminum[j]. Eleetrochemieal. Acta, 199, 7(1): -9 [15] Yu X W, Cao C N, Yan C W. Study on the formation mechanism of Ce conversion coatings on LY1 alloy [J]. Acta Metall. Sin., 000, 6(9): (,,. LY1 ±Ñ Ce Ä Û» [J]. Å, 000, 6(9): ) [16] Zhang K,Li W F, Du J, et al. Surface structure and corrosion resistance on the rare earth conversion coating of aluminum alloys in HF solution[j]. J. Funct. Mater., 010, 41(): (ß, Á, Ù. Î HF Ô Þ» [J]. ¾Í, 010, 41(): [17] Zhang J J, Li W F, Du J, et al. Preparation and performance of Ce-Mn conversion coating on Al-alloy surface at room temperature[j]. Acta Metall. Sin., 009, 45(1): (ß, Á, Ù. Ce-Mn ÖÆ [J]. Å, 009, 45(1): ) [18] Chen D C, Li W F, Wu G X. Preparation of chromefree chemical conversion coating on aluminum alloy and its performance [J]. Chin. J. Nonferrous Met., 008, 18(10): (Á Ì, Á, «Ã Ù. ž ÖÆ [J]. Ç Å, 008, 18(10): ) [19] Andre Decroly, Jean-Pierre Petitjean. Study of the deposition of cerium oxide by conversion on to aluminium alloys[j]. Surf. Coat. Technol., 005, 194: 1-9 [0] Mansfeld F, Wang V, Shih H. The inhibition of aluminum alloy corrosion by cerous cations [J]. Electrochem. Soc., 1991, 18(1): L75-L79

5 1 À Ø : Ce-Mn Ö Ã HF Ú º 4 [1] Guo R G, Wang X C, Geng Z L, et al. Preparation of chemical conversion coating on aluminum alloy and its performance[j]. Mater. Prot., 008, 41(1): (ij, Ú, ÇÙ. Ð º ±Ñ ÖÆ Þ [J]. ¾Í, 008, 41(1): [] Niu L Y, Jiang Z H, Li G Y, et al. A study and application of zinc phosphate coating on AZ91D magnesium alloy[j]. Surf. Coat. Technol., 006, 00: MECHANISM OF HF IONS IN Ce-Mn CONVERSION COATINGS ON Al ALLOY LI Wenfang, ZHANG Kai, DU Jun School of Materials Science and Engineering, South China University of Technology, Guangzhou Abstract: Distribution of Ce-Mn conversion coating was analysed with electron probe micro analysis,energy disperse spectroscopy, X-ray photoelectron spectroscopy analysis, respectively. X-ray diffraction was used to study the features of the phase composition of the conversion coating and the sediment in the solution containing HF ions. The results show that the element F does not exist in the Ce-Mn conversion coatings, and HF does not participate in the growth process of the coating. The main purpose of HF ions was in the initial stage. Al matrix and its oxide film (Al O ) in the surface of Al alloy were dissolved priority, so that cathode district which conducive to the formation of the coating exposures rapidly to the solution. Simultaneously, the total [AlF 6 ] in the solution is less than 1.8 mmol/l, completely dissolved. Key words: HF ions; Ce-Mn conversion coating; [AlF 6] ; sediment