Vol.26 No.4 姜应律等：利用极化曲线推测中性水溶液中钛合金表面的氧化还原反应机理 ·399 Electrochemical Reaction Mechanism of Titanium Alloy in Neutrol Water and 3% NaCl Solution Explored by Polarization Curves JIANG Yingly,WU Yinshun Materials Science and Engineering School,University of Science and Technology Beijing,Beijng 100083,China ABSTRACT The polarization curves of titanium alloy TC4 in neutral water and 3%NaCl solution were measured and analyzed.Their cathodic and anodic Tafel slopes were calculated to be much greater than 0.118 V.The cathode process(hydrogen evolution)of titanium alloy in neutrol water was controlled by the reaction H'+H'+e=H,'which explained well the cathode Tafel slope was about 0.23 V.The nonstoichiometric oxide Tio(0.5<x<1)as an in- termediate product took part in an electrochemical reaction was the controlled step in anodic process. KEY WORDS titanium alloy;hydrogen molecule-ion;nonstoichiometric oxide;polarization curve;Tafel slope 堂6望6堂s望a6里s2 eo o望sc6业as望e6Y6Y6望6Ts空ooTes2c56 YaoYo67osYc6望m堂6ass望es堂c62e%里a6望s空sYe6望as业es理es堂s望ess堂sYw里e (上接第394页) Temperature Effect on Thixoforming of Spray-formed 7075 Alloy LIU Huimin,CHENG Junsheng,CUI Hua,YANG Bin,ZHANG Jishan State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China ABSTRACT Unilateral compression tests on spray formed 7075+TiC Al alloy at semi-solid state were carried out using a Gleeble-1500 dynamic material testing machine.The microstructures of vertical and cross sections of the specimens after deformation were observed by SEM,and the grain size was measured by a mean linear intercept method.The relationship between the deformation temperature and grain size was analyzed.The results indicated that the grain size increased with the increase of deformation temperature and distributed in 10-21 um at 580- 620C.When the deformation temperature was up to 610C with a deformation rate of Is-,the alloy revealed ad- vantageous thixoforming performance. KEY WORDS spray formed 7075+TiC alloy;semi-solid state;compression deformation;deformation tempera- ture;microstructureV b l . 26 No . 4 姜 应律等 : 利用 极化 曲线 推测 中性 水溶 液 中钦 合金 表面 的氧 化还 原反 应机 理 一 3 9 9 - E l e e ort c h e m i e a l Re a c t i o n M e e h an i s m o f iT tan i um A ll o y i n N e u ort l 认/a tre an d 3 % N a C I S o lut i o n E xP l o r e d by P o lair z at i o n C rvu e s 汤阴刀G K n g l认那 U 竹 sn h “ n M at e r i a l s S e i e n e e an d nE g in e e r ln g S e h o o l , nU i v e rs ity o f s e i e n e e an d eT e h n o l o gy B e ij in g , B e ij n g l 0 0 0 8 3 , C h i n a A B S T R A C T hT e P o l硕aZ ti o n e vur e s o f t it 丽um a l oy T C 4 in n e u tr a l w at e r an d 3% N aC I s o lut i o n w er e m e a s ure d an d an aly z e d . hT e ir e hat o d i e an d an o d i e aT fe l s lop e s w e r e e a l e u lat e d t o b e mu e h gr e at e r ht an 0 . l l 8 V T b e c at h o d e P ro e e s s (hy dr o g e n e v o liut on ) o f it t翻um a lloy in n e u tr o l w at e r w as e o n tr o ll e d by ht e re ac it on H 干 + H + + e = 凡 + w h i e h e x P l a ine d we ll ht e e hat o d e aT fe l s l o P e w a s ab o ut 0 . 2 3 V hT e n o n s t o ihc i om e itr e o x i d e IT O ,、 (0 . 5 < x < l ) a s an i n - et mr e id aet Por d cu t ot o k Part in an e l e e otr e he m i e a l er ac it on wa s ht e e on otr ll e d s t eP i n an o d i e P ocr e s s . K E Y W O R D S t i ant i um a ll o y : hy d r o g en m o l e cu l e 一 i o n : n o n s t o i e h i o m e itr e o x i d e : P o liar azt ion e vur e : aT fe l s l o P e ( 上接 第 3 94 页 ) eT m P e r a ut r e E fe e t o n T h i x o fo mr i n g o f S P r ay 一 fo mr e d 7 0 7 5 A ll o y LI U H 扮im in , C 刀万刃G uJ n s h e gn, C UI H扮,a YA N G B in , 刀翻刀G isJ h a n S t at e K 即 L a ob r at 0 ly of r A d v acn e d M e atl s an d M ate ir al s , U n i v ers ity o f s e i e n e e an d eT e hn o l o gy B e ij in g , B e ij ign 10 0 0 8 3 , C h in a A B S T R A C T U in lat e r a l e o m P r e s s i o n t e s t s o n s rP ay of rm e d 7 0 7 5+ IT C A I a ll o y at s e m i 一 s o l i d s at e we re e a r i e d o ut u s ign a G l e e b l e 一 15 0 0 dy n am i e m ate ir a l t e s it n g m ac ih n e . hT e m i e or s t u c trU e s o f v e rt i e a l an d e r o s s s e e t i o n s o f ht e s P e e 加ens a fte r d e of 加 a it o n w e re o b s e vr e d by S E M , 阳 d ht e gr ian s讫e w a s m e as ur e d by a m e an lin e ar int o cr e Pt m e th o d . T h e er l at i o sn h i P b e wt e e n ht e de fo mr at i o n t em P e r a 奴ir e an d gr ia n s i z e w as an l y z e d . hT e er s ul t s i n d i e aet d ht at het gr a i n s i ez in e er as e d w i ht ht e in e r e a s e o f d e fo mr a t i o n et m P e r a tL 叮e an d d i s itr b u t e d i n 10 一 2 1 脚 a t 5 8 0 一 6 2 0 oC . 从币e n ht e d e fo mr at ion t e m P e r at u r e w a s uP t o 6 10 oC w ith a d e fo n n at i o n r a te o f l s 一 ’ , ht e al loy r e v e al e d ad - v an t a g e o us t h i x o fo mr i n g p er fo n n an e . K E Y W O R D S s P r a y fo mr e d 7 0 7 5 + IT C a ll o y : s e m i 一 s o li d s at e : c o m P r e s s i o n de fo mr at ion : de fo mr iat o n t e m P e r a - 奴叮 e ; m i er o s trU c ut r e