Al(99.95%) Al-10Sr Ñ Sr(99.5%)

«3 Í «6 ± ²» Vol.3 No.6 01 Ä 1 Journal of Chinese Society for Corrosion and Protection Dec. 01 Sb Î Mg-5Al-Sr Õ Þ ÖËÆ 1 1 1 1. غ Æ º ºÜ 10016. µà Ì Ä Æ È À 155 : Û«º ±± µ Å Sb Mg-5Al-Sr Ò 3.5 mass% NaCl µ ±µá ³ Mg-5Al-Sr-xSb(x=0 0.3 0.6 1.0) Ò 3.5 mass% NaCl µ ±Û Ñ ± ±Ú Ð Õ τ SbSr Æ ß ÓßØ Ò ±Ò ¼¾ Al Sr ÁÍÊÑÒ ± «Mg-5Al-Sr Ò 0.3% Sb ¼ ÁÍ α-mg Ð Al Sr ±Ê ¼¾ÄØ Ò ± Ö À ± ¾ ±Ä Ò ±µáï Ê : Mg-5Al-Sr Sb ±µá Đ Ð : TG9.6 È Ò : A Ç : 1005 537 01 06 078 07 1 Ù«Mg-Al-Sr Đ Ñ Í Ê ¾ ¹ À ± ÀÅ À Î [1 13] AJ6(Mg-6Al-Sr) Ñ Â ÉÇ Ã 6 Æ [13,1] à ī² Ñ Ô Sb Mg- 5Al-Sr Ñ À Æ [15] Mg-5Al- Sr Ñ Ë» α-mg»½ ÜËË Al Sr «Ô Mg 9 Al 3 Sr (τ ) É Sb Ü Ñ É «Đ SbSr «Ô τ Æ Sb 0.3% Sb» ÀÌ α-mg ««Al Sr É µ»½ã Æ Sb Ñ SbSr º³»½ Al Sr Sb ÀÌ ¼Î Ñ ¼ Ý Ñ [16] Mg-Al-Sr ĐÑ À Õ Ø Ä«Mg-5Al-Sr Ñ ÀÅ Sb Mg-5Al-Sr Ñ 3.5 mass% NaCl À Æ Í ÛØ : 01-0-8 Ô : Á Ç Đ (BE010103) ¾ : 1968 Å ¼ º, Æ ÒÑÓ Ë² Å : E-mail«zililiu@sohu.com ß Ï Ö ÐÅ Mg(99.95%» ) Al(99.95%) Al-10Sr Ñ Sr(99.5%) Sb Đ (99.9%) Ë «Ñ ¹É» ² 1 ȹ Ñ Ï 0.5%SF 6 CO Ñ ß ÄÅÆ ³ Ü 780 0 min ܺ ÐÓ Ð 50 Ñ» É» Ñ Õ Ü Ñ µ Ð 0 mm 10 mm 3mm Ö É Ô Èµ Ü 3.5% NaCl 100 h 0 ßÜ 00 g/l CrO 3 19 g/l AgNO 3 Ê 10 15 min Ý Ý Ô Ø Èµ ¹ Ñ É» µ «µ µ Þ Ñ Ï Ã ν Å ÐÅ ν = W 0 W t S 0 t (1) W 0 Ð Ö W t Ð ÜÝ Table 1 Chemical composition of experimental alloys (mass%) Alloy Al Sr Sb Mg 5 Bal. 5 0.3 Bal. 5 0.6 Bal. 5 1.0 Bal.

6 Ð : Sb Mg-5Al-Sr Ò ±µá 79 Ý S 0 Ð ² t Ð µ CH660A Æ ¹ÅÃ Ñ ÚÅ µ Solartron S 160 / Ê»Þ Á Solartron S 187 Æ ¹»ÞÁ Ñ Æ ¹ Û Åʹ½ Åà Р1 cm Åò º Ö Ü Ü Ä Ã Ð 3.5% NaCl 0»Þ NaCl Ý Ü Ë É «Æ ĐÅŹÆßÆ Ð ¾½Æ ÉÆ Ð Æ Æ ÐÅ ÃÆ ÅÃÆ ¹Æ ËÜÏ ÎÝ 80 mm ÚÅ ÅÆÕÆ Ã Ð 10 mv/s ÆÕ³ 1.8 V 0. V Æ ¹ ÅÆ Í ³ Ð 0.1 Hz 10 khz Æ 5 mv µ XJP-300 Á Ñ 3.5% NaCl À» Ü ³ 3 ÐÑ 3.1 ÝÜ Mg-5Al-Sr Ñ 3.5 wt% NaCl Ê 100 h Ü Ã 1 ȹ Å Ð ³ Mg-5Al-Sr Ñ Ã À» Sb Ü È Ñ Ã È Sb Ð 0.3% Ñ Ã À Ð 0.35 mg cm d 1 Mg-5Al-Sr Ñ ÀĐÐ Î Æ Sb Ñ Ã Sb Ð 0.6% Ñ Ã Ð 0.57mg cm d1 Song [17] à (0.5 mg cm d1 ) Þ Ñ ÏÊ À 3. Ú Ð» Sb Mg-5Al-Sr Ñ 3.5 NaCl ÚÅ Æ Å Þ ½ ÆÕ (E) Æ ½ (logi) ÌÅ ÎĐ Ñ ÚÅÏ Corrosion rate/ mg cm - d -1 1.0 0.8 0.6 0. 0. 0.0 Fig.1 Corrosion rate of experimental alloys Á Tafel Tafel ÚÅÃÑ Å ĐÑ Æ ½ corr ÆÕ (E corr ) Å Æ (R p ) [18,19] ² ȹ ¹ ËØ ÆÕ E corr Þ Ó Þ ² Þ Ý Ó»ÀÖ Ã Ñ² Å Æ R p ¼² Æ Ã À ¹ ² «Æ ¹² Í Á ÖÍÏ ² Å Æ Þ À Þ Æ Ã υ Æ ½ corr Å [0] Å υ = M nf corr = 3.73 10 corr M/n () υ Ð Ã g m h1 corr Ð Æ ½ µa cm M Ð Ö g mol 1 n в Æ Ý mol F Ð Å 968 C 6.8 A h ÂÉ Æ Ã υ Æ ½ corr É ÎĐ Í corr ز Æ Ã ² Å Ð Mg-5Al-Sr Ñ ÆÕÀ Å Æ À Mg-5Al- Sr-xSb Ñ ² ½ À Ê ½ Ó 3 Ð Sb Mg-5Al-Sr Ñ Æ ½ Æ À Ð Mg-5Al-Sr Ñ Æ ½ À Ð.599 10 3 A cm Ñ Í Ê À à Sb Ü Ñ Tafel lg (/ A cm - ) -1 - -3 - -5-6 -7 Passive zone....... Pitting -8-1.8-1.6-1. -1. -1.0-0.8-0.6-0. E/ V...... Fig. Polarization curves of experimental alloys Table Corrosion current density, corrosion potential and linear polarization resistance of experimental alloy Alloy corr/ A cm E corr/ V R p/ω cm.599 10 3 1.377 17.7 1.07 10 5 0.639 6053. 1.91 10 3 0.988 38..07 10 3 1.09.7

80 ß¹ 3Í ÚÅ Tafel ÚÅ Å ½Ð Í ² É ß ÖÍß Æ ¹ Í Ð Æ «Ü (Mg ) Ã Æ ÐÎ Ã Ù Æ Ü (Mg ) Ù ÏÆ Æ Æ Æ ÆÕ ± µ Ó Sb µñ Å Æ Æ ½ ² Ä ³ Ñ Ô Sb ÀÌ Î Mg-5Al-Sr Ñ À Þ Sb Ð 0.3% Ñ ÆÕ Mg-5Al-Sr Ñ «0.738 V 0.58 V 0.5 V 0.39 V 0.33 V ÀÆÕÙ «Ù ( ȹ) 0.58 V 0.5 V Ù Æ ² Ý É Î Æ Æ» Р0.5 V Å ÆÜ Í Ý Mg(OH) «Ð ºÃ [1] Æ Í ³ ¼ 0.39 V 0.33 V Ù ÖÍ É«Ñ Æ» Í ¾ 0.3% Sb Ü Ñ Æ ½ Mg-5Al-Sr Ñ «À Ð 1.07 10 5 A cm Å Æ ¼Mg-5Al-Sr Ñ 3» Đ Sb Ð 0.3% Ñ Ê º À Æ Sb Ñ ÆÕ Å Æ Ì Æ ½ ÑÃ Ñ Ó À Sb Ð 1.0% Ñ ÆÕ Ð 1.09 V ß Mg-5Al-Sr Ñ 0.85 V Å Æ Æ ½» ÊºÊ Þ À 3.3 Ì a b» Ð Ñ 3.5% NaCl corr / ma cm - 3.0.5.0 1.5 1.0 0.5 0.0-0.5 1.0 1.5.0.5 3.0 3.5.0 Sb Content/ % Fig.3 Effects of Sb content on corrosion current density of experimental alloys Ô ÍÚÅ ÃÑ Ñ Æ Ð CDCÅ R(Q(R(CR)))(CR) Ñ Æ Ð CDCÅ R(Q(R(C((LR)(CR))))) 5 ȹ Ñ Bode ( 6) Å Ð Ñ Nyquist ÚÅÏ À» Í Í À Þ Êº ÉÔ ÊºÊ ÆÝ Ñ Ê «À «Í Í À Þ Í» «À Þ Makar [] Ä» Ñ Nyquist ÚÅ Í Þ Ã ÎĐ Nyquist ÚÅ»Þ µã ÚÑ Í Z m / k cm Z m / k cm 0 - - (a) -6 0 6 8 10 1 1 16 Z Re / k cm 0 - - (b) -6 0 6 8 10 1 1 16 Z Re / k cm Fig. Nyquist plots of experimental alloys. (a) experimental values; (b) fitted values Fig.5 Equivalent circuit of experimental alloys. (a),, ; (b)

6 Ð : Sb Mg-5Al-Sr Ò ±µá 81 Þ ÂÞ Ñ Ã ÇÞ Ñ ÇÞ Ñ Í Þ Â (r) Đ Ð r > r > r > r ʺ À Ð ± Í Þ ² É Æ Æ Í Åµ Æ Æ R t Õ»Ô² CPE Ø Æ Æ R t ² ¼ ÆÕÐ E corr Æ Í Æ Æ Æ Í ÈÍ R t Ñ Æ ÍÑ È ³ [9,0 3] Æ Æ Æ Æ C dl Ê Ê ¼ ² É½Û ½ ß Í ÝÜ Æ ² Û Æ ² Ð Æ Á Æ ²» ²» ¼ Ï Õ ÕÔ Í Õ»Ô² CPE Ú Æ Æ C dl ĐÃ Þ Y 0 n ¼ CPE À Z CPE =1/[Y 0 (jω) n ] 0 n 1 Z CPE Ð CPE Y 0 ¼ CPE ß ω Ð»Í n Ð CPE ¼ (ÜÎ Æ ² Í Æ»½ À ² ß Í Þ»¼ À Ø ¼ À Þ) Þ n» Ð 0 0.5 1 CPE» Ú² Æ Warburg Æ Æ [] n Þ CPE Þ Æ ² Þ ² ÃÈ ² n Þ CPE Þ ² ² ÃÏÐ À Phase angle/ deg 60 50 0 30 0 10 0-10 -0-30 10-1 10 0 10 1 10 10 3 10 f/ Hz Fig.6 Bode plots of experimental alloys Þ [3] Í Þ» Ñ ² Í [3,5] Ü Ò Ý Ý Í Å Æ C f Æ R f Ø Í Þ Ñ ² Æ Ü Î Þ ² Þ Ü Þ È [6] ÂÉ Æ ¹ [3] Æ ² «Æ Æ E À² ˱ X µæ / Åß ²¹ÐÅ Y = jωc dl 1 ( F R ct X dx de )/[1jω/( X )] (3) X Y Ðß ω Ð»Í C dl ÐÆ Æ R ct ÐÆ Æ F Ð ÅÆ X в Ë ± X = dx/dt (3)» Í» ÀÜ»ØÙ Í» Þ ( F / X)( X/ E) >0 Æ ¹ Í» À Þ ÚÅ Ì Å Ð Ñ 3.5mass% NaCl ² Ñ ß É Å ² θ ز¹ Ñ Æ ² ˱ X Æ Æ ÆÕ E Ç µ (dθ/de) <0 ÉÔ ÙÐ ÆÆ ÆÕ E Æ Æ ß» µ θ Æ Æ Çµ ( F / θ) <0 À³ß ( F / θ)( X/ θ) >0 Ç Ñ Æ ¹ Í» À Þ ² 3 Ð Ñ ZSimp Win ŲÃÑ Æ R s Ð Æ R t ÐÆ Æ CPE Ð Õ»Ô² C f в Æ R f Ð ² Æ R L L» Ð Ñ ² Æ Ü Î Æ»Þ² 3 É Å Ð ÈÅÑ R s Õ Æ Í ÆÕ Å» Ñ R t R f Ñ Õ Í Î CPE C f ¼ Ñ Ê ½ 0.3%Sb ÀÌ n Table 3 Equivalent circuit parameters of alloy,, and Alloy R s/ω cm R t/ω cm CPE C f /10 3 F cm R f /Ω cm R L /Ω cm L/H cm Y 0 /10 6 Ω1 cm sn 0.5 1053 10.5 0.797 3.17 33 39.13 96 6.78 0.935 1.136 768 80.8 150..37 1879 8.16 0.890.07 538 5. 1365 9.57 0.83.875 61

#\3$h{- 3U = Mg-5Al-Sr m9 &7o m9 3$ ) XPS 6L AZ1 AZ501 AZ91 ( Mg-Al o BÆÆg Æ iæ6" D 7 5 m9& {: EQ" ad Al h O li G h BÆÆ au >' VCm9?3$( sd Mg h O li Al ` h O m$qf H B 1 Al O : 7> m9 {& #" Bl MgO : MgO 3$8"# H ThA&X$ 3. Zy o Mg(OH) : 7> m9 H&B b 7 l ((;m9 3.5% NaCl #(A D QKlw $Q ( : 3$8"#`d 6 #3$x 3$$ ' dmz} m9 i m9& Xr7S N9 (Vx; ( JFY3$ 3$v"l $ R.& 3$$ M d $Q Cl )! :} α-mg h! _7 R. ' # bf p ` " Z " # [ ( X r A3$Æq E q} Ja $Æ N 1s (1 ) lm9# ` 7! 1 O H k } V! F $ { 9 /l3$au#f $f m9 # $ q 9q EP& $Qh $ " l $h $ 1 /11lW} m9 E /Aa α-mg hfx$q Ksl$f HaU M,f7 Al Sr M k7 p τ EQ dmp Æ &Xi -&X m9 $ud k7 p τ m9 n&x H e H & $ 3.5% NaCl #(A D#.Gw h V z = 6&X Mg Mg e a3se # o" 6 =% h;m9 -&X Mg H O Mg OH H #` 7! > q bv m9 #F MgH H O Mg OH H ` 7 `BJY" $ $ qq &X Fy$Q Mg OH Mg(OH) m9 E /Aa α-mg,f7 Al Sr dmz} H Qh =V &Xi -& M 0 /1 ` 7 SbSr EQ dm P X bv r; 6 H TF H _ m9 $ud ` 7 SbSr " H e-hhtf H) D ph m9 # b Hjs ` `" $ VC b d Mg(OH) OH : $Q Mg(OH) m9 E /Aa α-mg 7 Al Sr M $Q m9&: 8!/)A z3$æq js ` 7 SbSr EQ dmp m9 E m9 $bæ " lp wwsd $Æq $ud js ` 7 SbSr 3$ { [ ` d" b 7e l"t( ;m9 Mg-5Al-Sr 3$ 36 h $' Hp{ Z} }m $fj ~ Q T m9& } ) 3$ (;m9 Mg-5Al-Sr-xSb $ 3.5% NaCl # [ (A D# z3$æq E d $Æq E " F m9#! (β ) 3$aU# m9& $QRb {K : Song Rb )K 8 3 p [1] p p [7] [7] Fig.7 Corrosion morphology of experimental alloys etching in 3.5% NaCl solution. (a) Mg-5Al-Sr, 1 h; (b) Mg-5Al-Sr-0.3Sb, 1 h; (c) Mg-5Al-Sr-0.6Sb, 1 h; (d) Mg-5Al-Sr-1.0Sb, 1h; (e) Mg-5Al-Sr, 36 h; (f) Mg-5Al-Sr-0.3Sb, 8 h

6 Ð : Sb Mg-5Al-Sr Ò ±µá 83 (1)»½ β Ø Ñ Al Sr ʺ½»½ Ñ ² «Ñ ² ² Ê Õ Ã ( ) ÉÐÑ ÅÆ α-mg»½ β À ĐÐ Đ ±» 7f Ð Ø Ñ Mg-5Al- Sr-0.3Sb 8 h ³ ÀÔß Ð Ð Al Sr Ö Í Þ² α-mg Ü»½ β ² É Ø [8] Ð Ñ β ² É ¼ ½Ò ph ³ ¼Û Å Â À ß ÊµĐÆ ½ È µ Ý«Ü Í Ñ ÀÌ Æ Í Ü (Mg ) Ã Þ Mg Ã Æ ÐÎ Ã Í ÐÇ Ã ² Ù Æ Æ ÆÕ ± É Æ ÎÜ ( Cl ) Ò Ý Ý α-mg ¾ Í Ð Æ È Ç Æ ² ¹² ³ Î Ñ À () ÖÓ β»½»¼ Ø Ñ τ Ñ Đ SbSr Û Å Í» ÃÐÞÒ² Î [9] «ÆÇ [30] ëʺ ÃÐ α-mg «Ñ Đ Þ ÏÒÞ Ñ ² ß Û ÆÞ «Î ² [31] µñ Ã Ì 5 Ñ (1) Ñ Ô Sb ÀÌÎ Mg-5Al-SrxSb(x=0.3 0.6 1.0) Ñ 3.5% NaCl À Sb Ð 0.3% Ñ ÀÀ Æ Sb Ñ Àº³ () 0.3%Sb Ü Ñ ½»½ Al Sr ² É ÀÌÕ ÆÑ Í Mg-5Al-Sr Ñ Ñ ÆÕ Æ ½ Ã Ñ ÀĐÐÎ É [1] Baril E, Labelle P, Pekguleryuz M O. Elevated temperature Mg-Al-Sr: Creep resistance, mechanical properties, and microstructure[j]. JOM., 003, 55(11): 3-39 [] L Espérance G, Plamondon P, Kunst M, et al. Characterization of intermetallics in Mg-Al-Sr AJ6 alloys[j]. ntermetallics. 010, 18(1): 1-7 [3] Hou J C, Guan S K, Ren C X, et al. Effect of small addition of strontium on microstructure and electrochemical performance of Mg-Mn sacrificial anode[j]. J. Chin. Soc. Corros. Prot., 006, 6(3): 166-170 (Ú, Ï, ĐÅ. ƻР¼  [J]. ² ³ ¹Ð¼, 006, 6(3): 166-170) [] Trojanov Z, Drozd Z, Luk P, et al. Mechanical properties of a squeeze cast Mg-Al-Sr alloy[j]. Adv. Mater. Sci. Eng., 008, 9(): 97-10 [5] Aljarrah M, Parvez M A, Li J, et al. Microstructural characterization of Mg-Al-Sr alloys[j]. Sci. Technol. Adv. Mater., 007, 8(): 37-8 [6] Bai J, Sun Y S, Xue F, et al. Effect of extrusion on microstructures, and mechanical and creep properties of Mg-Al-Sr and Mg-Al-Sr-Ca alloys[j]. Scr. Mater., 006, 55(1): 1163-1166 [7] Bai J, Sun Y S, Xue F, et al. nfluence of annealing on microstructures, mechanical and creep properties of Mg- Al-Sr alloy[j]. Mater. Sci. Technol., 006, (10): 108-11 [8] Cao H B, Zhu J, Zhang C, et al. Experimental investigation and thermodynamic modelling of the Mg-Al-rich region of the Mg-Al-Sr system[j]. nt. J. Mater. Res., 006, 97(): -8 [9] Zhao P, Wang Q, Zhai C, et al. Tensile and compressive creep behavior of coarse-grained Mg-Al-Sr castings[j]. Mater. Sci. Forum., BeiJing: 006, 56-59: 171-17 [10] Parvez M A, Medraj M, Essadiqi E, et al. Experimental study of the ternary magnesium-aluminium-strontium system[j]. J. Alloys Compd., 005, 0(1-): 170-185 [11] Czerwinski F, Zielinska-Lipiec A. The microstructure evolution during semisolid molding of a creep-resistant Mg- 5Al-Sr alloy[j]. Acta Mater., 005, 53(1): 333-3 [1] Pekguleryuz M O, BarilE,Labelle P, et al. Creep resistant Mg-Al-Sr alloys[j]. J. Adv. Mater., 003, 35(3): 3-38 [13] Pekguleryuz M O, Baril E. Development of creep resistant Mg-Al-Sr alloys[j]. JOM., 001: 119-15 [1] Klüting M L C. The new BMW inline six-cylindercomposite Mg/Al crankcase[a]. MA 6nd Annual World Magnesium Conference[C]. Berlin, 005: 51-60 [15] Zhu X C, Liu Z L, Zhou G B, et al. Effects of Sb addition on microstructure and properties of Mg-5Al-Sr alloy[j]. Mater. Sci. Technol., in accepted (¹,, µ. Sb Mg-5Al-Sr Ó Â [J]. ¼ ÆÆ, à ) [16] Yang Z, Li J P, Zhang J X, et al. Review on research and development of magnesium alloys[j]. Acta Metall. Sinica., 008, 1(5): 313-38 [17] Song G, Atrens A, Dargusch M. nfluence of microstructure on the corrosion of diecast AZ91D[J]. Corros. Sci., 1998, 1(): 9-73 [18] Shi Z, Liu M, Atrens A. Measurement of the corrosion rate of magnesium alloys using Tafel extrapolation[j]. Corros. Sci., 010, 5(): 579-588

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