陈三雨翻译文献.pdf

献 功 恕翼 刀双篇认蕊恶 思 黑 土 艇悠 黑 骤 之 黑徽 七 七 且 八 一毛 仟 M a gn e s i u m a ll o y C o rr o s i o n D i f f u s i o n c oa t i ng i n di ea t e d t h a t ra t eo fAZ 91 D 1 I n t ro d u e t i o n T h ea ppli e a t i ono f m a g nes i u m a l l o y s i n v a r i ousen gi neer i n g f i e l d s h as i nerease d s t ea d i l yi n reeen ty ears b eeause m a g nes i u m a ll o y sex h i b it an 就traeti ve eom b ina tion oflowdensity and h i gh ratio ofstrength to weight H owever t h esea ll o y sarever y r ea e ti ve i n n a 七u r e a n dth e o x i d e f il mf o r m e d on t h ea l l o y sna t u ra ll y eou ld no t P rovl d eenou g n P ro t ec t 10n L 一 Inelr i nsu f f i e i en t eorros i onres i s t anee h as b eenaser i ous li m it a ti on t oa wid era PPli ea ti on i n P rae t i ee T O en h a n ee th eeorros i onres i s t 初eea n dimProvethePaint adhesion ProPerties ofmagnesium all o y s t h eeonven ti ona l现ethods are ehemie欲 eonversion tre乱m ents T hewell 一 k no w nan d e f f e e ti veeo n v ers i on P roeess t o a l u m i n u md i f f u s i oneo a t i n g F u r th er m ore th eeorro s io n b e h a v i ouro f th e d i f f u s i oneo a t i n gw ase m P ha s iz e d i n t h i ss t u d y P ro d ueea P ro t ee t i ve l a y eron t h esur f a eeo fm 乏 lglle siu m a lloy s 15 b a s e d o n t h e im m e r sio no fth ea lloy s in a b a th e o n taining e h r o m a t e H o w e v e r t h e c h ro m a t e b a tl z sare b e i n gP ro g ress i ve ly res t r iet e dd ue t o i t s h i gh t o x i e i ty Th ereeen t resear c h eson t h e P ro t ee ti ono f m a g nes i u ma l l o y sar e f o euse d on th eenv i ron m e n t a l a n dh ea l七hf riendlyPro e esse s an d v a r i ousnove l P ro eessesa 它 b r o u g h t f o rw a r d 4 一8 Int h e or y th eeor ro s i onres i s t aneeo fr n a g n es i u m a l l o y sean b e ir np ro v e d b y r no d if i ea t i ono f t h e i reo m p os i ti on a n dm i C ros t ruc t ure A P ro m i s i n g m e t h o d 1 5 b ase d on t h e d i f f u s i on a l l o yi n gth eor y eorros i on P ro t ee ti on b e i n g a t t r ib u t e d t o th e f o r ma t i ono f aeo 就ing eom prised of intermetal l ie eompou nds whi c h eanno t on l yimp rove t h eeor r os i onres i s t anee b u t a l so p r o v id eenou gh a dh es i on s t ren gt h an db e tt er m e c h an i ea l p r o p er ti es W a r lg s r es e a r e h g r ou P 歌temPtedtoProteet the租agn esium al loy by pow derpaek a l um inized eo ating f r o现 1999 h o w ever t h eres u l t s w ereno t d es i re db eeause th e m a g nes i u r n a l loy sareex t re m e ly eas yt o b e o x idiz e d an dth e i r 租elting pointtemPera t ures are very IOw T heref o re i n thi srese a r e h di f f u s io ne a t i n gt ee h n i q u e w asearr i e d ou t on A Z91D m a g nes i u ma ll o y s P e 二ime n s by e o mbina t角n of magnetroll sPuttering dep osi tion and v a eu umann ea l ing tof o rman exPeeted t Ph D to wh o m eor re s p on d enees h ou ldb ea dd r ess e d E 一 m a i l hwh uo y a h oo eo m 2 E x p e r i m e n t a l R ee t an g u l a rs p ee im e ns wi t h t h es i zeo f 1 5 mm 只1 0mm x 3 mr n w e r ee u t f r o m s a n d 一 eas t A Z 9 1D a l l o y T h eno m i La l e h e m i e a l eo m p os i t i on o f th e 威loy 15givenin工幻 le 1 Th es u r f a e e so f t h e sPe e im e n s w e r e m e e h a n ie allyP o lish e d b y e m e ry P子 Pers uPto1000 grit七0 e n sure the samero ug hn ess f oll o w e db yw as hi n gwi t h aee t one in anu lt rason ie b a t h Pl a n e m a g ne t rons p u t t er ing e 卿ipm en t m o d e l o f S BH 一 511 5 D 从 a su s e d 七0 eo at a l um inum on AZ91 D alloysu bstrates B e f o reS P u tt er i n g d e P os i七 ion t h e s P ee im eno w eresan dbl as t e d t o imP rove t h ea dh es io n b e七 wee n theAIeo ating a n dthe sub stra te T he sPut teringdePo si七 io nw as c o ndu eted f o r 1 5 h u n derthe pow er of 15 0 0 W a nda rgo n pressu re of 0 2 P a A v a euu m annea li n gt rea t m en tw as p er f o r m e d i n a t u b e f u rnaee Th eanne a l i n gt rea t m en tw aseon d ue t e d a t450 o Cf o r 2h T O e v a lu a t e t h ee 旋etofthetreatm ent a h y d ro g en evo luti onra t e m e th o d w asuse d t o m eas ure t h eeor ros i onr a t eo f th es P ee im ens d ur i n gim m ers i on t es t a t 25士Z O Cf o r 10 0 h T he sc l l ematie d ia罗am ofthe set up 15 shown inF ig 1 a n ditsPrinei p lew as explained indeta ilinliterature 9 In addition t h e p o t e n t i o d y n a m i e P o la r i z 就ionm ea su remen t in3 5w t Petn eutral N aC Isolution was earried out w itha three 一e l ee七rode e ell T h e sPe eime n w a swelded w ith a eoP Per w ire a nd em bed dedin ePo xyr esin aswo rkele etrode f o r ele etro ehem iealte sting an d t h e w or k a r ea 1 5a b ou t1 e m 2 Th e P o l ar i za ti onran g e w as f r o m 一0 5 V to 0 5 V v s the oPeneire uit Pote狱ial 肌d ther neasuremen twas com mencedata Scanningrate of0 25 m V 5a f t erthe Systemreaehedasteadyst就e Themierostrueture and eom Po sition ofthe anneal trea t edspeeimen swas eharaeterizedusinga Philips X L 30 eanningeleetron oieroseope SEM equip ped M a七e r Sei T e ehn ol V O I 23N o 3 2007 T a bl e 1 Ch en i i e a l eo m p os iti onso f t h e a s 一e a s t AZ91D m a g neo ium a l lo y inw tp e t 二蓄护 工 浇 r一 仲三 石r气 j声 一 万吃含 二 BU阳t te 班 B e a k e Se als nt FU n n el S Pe ei m e n Fig 1 S ehe m atie d i a罗amofthe set一u p f o r n ie 韶urem en七 of hy d l ogene v oluti on r a t e w ith ene r g y disp e r siv e X 一 r 盯 speetroseopy E DS a n d 苏r盯 山价a ctom e饶rw ithCuK ar耐ia tion 3 Results alld Diseussion 3 1八五盯05亡 ru e亡ur e F igu re2 shows th esu rf ae e a n d tlie ero ss一see ti on m or P h o l o g i eso f th es P u tt ere da l u m i nu m eoa ting on th esu b s t r a t eo fAZ 91 Da ll o y Th eeo a t i n gw a s no t eon1 P a c t a n d so m e h o l es a n d i n t ers t i c e seoex l s 七ed in thedepo sited aluo in um eoa t ing a l t h ou 沙 the sput tering Pa r a m eterswere oPtimized Thestructure o f the eoating a p PearedtobetyPiea l eylinder erysta l T het址ckl less ofthe eoa ting reac hedn ea r l y s拼m a f t er 1 5h sPuttering depo sitio n I n o rde r to ob ta i naeom Paet sPutte ringe oa t ing v a r i ous P a r a m e t e l s was eondu eted howev e r th e q ua li t y o ft h ee o a t i n gw a s no t s a t i s f i e d B yt a k i n gi n t oe ons id er a t i on o f th ere ae ti v i t y o fm a g n esiu ma ll o y s a n d t h e P r o p e r t i eso f p 勿si ealval o r d epo sit io n P VD e o a t ing i t w as h a r d t o P rov i d ea g oo d P ro t ee t i on t o t h e m a g n es i u m a l l o y s j us t b yP V D e o a t i n g a l t h o u g h s o m e a t t e m Ptw as m a d e to e x P l o i tth e P ro t e e t i on m e t h o d s f o r th e m a g ne s i u m a l l o y s b yP VD t e c h n i q ue s Th e re f o re t h es P ee im en w a s t re 战ed by the v a c u u m 淤 nea l i ngaf t er eoati ngalu mi num i n or d er t o f o r m a d i血sion eo乱ing Figu r e 3 oh o w sthe surf a ce a n dthe eross一s ee ti on m or P h o l o gi eso f t h es P ee im ens wi t h a d i伪sion eo a t i ng Af te a n nea l t rea t m ent t h esur f a ee m or Ph o l o gy b eea m es m oo t h an dd ense a n d th e d e f e e t s sue h as h o l esan d int ers ti ees d i s a p P e a r e d T h eeross 一s ee t i ox l m or P h o l o gyin d i e 就ed tha t anew eoating near ly30 粼m f o r m e d on t h esur f a eo fth e sPe eime n an d int e g r a t e d wi t h t h esu b stra t e 饰m e t allurgy The adhesion strength of thedi f f u sion eoa t ing inereasedgreatly Inthedif f uoion eoati ng a 11 g ht P h a s e f o r m e d aeon t i nuous m a t r i x a n d a d a r k P h a s e w a s el l 1 e dd e dinth e ligh t ph a s e 玩 addi七 i o n so m e Fig 2 5 二faCe a a l l d eros s 一s e e t io n b mo r p h o logie s 试 the 印uttered alum l n u m coa ting o n the吕ub s tra t eof AZ 9 1 D all即 F ig 3 S u r f a C e a an d e r os 一s ee t io n b mo r p h o l o gie s o f t h e spee im ens withdi f f u s i o neo 乱ing 歌er Sei T e ehn ol 功 12 3 N o 3 2007 381 b Mg廊 a MgK a 瞥 w tp c t 5 9 5 4 4 0 4 6 a tP C t 6 20 2 5 79 8 A I K以 A IK 以 002刀03 004 0 05刀06 0 07 0 08 0 09 00 10 00090门8 02 7 0 b 3 石04 5 0 5 4 06 3 07 208 1 0 9 0 0 Fig 4E DX re s u lt so f th e li g ht Pha s ea n d the da rk Ph a s e in 七hed if f u sio neo a ting 丢 一一Bar eal loy y y 一一o一Wi t hd if f u sio n e o at旧 g g g 才 声 声 一z 尸尸 r 一o o 一一 一一了户 才才 一二幻 一 一子 子 1 1 111勺 11 1 1 3 2 C o r r o 应皿乙毓a讨or T hehydrogen evolution rates ofthe bareA Z91D alloysPeeimen and the sPeeim en w i七 hdif f u sio n e o at ingim m e rsed in3 5 w 七 Pe t N aCIsolutio nare shown inF ig 5 A s the o ve ralleo r os i onreae ti ono fm a g ne s i u m a t i t s f r eeeorros i on P o t e l l t i a l ean b eex P resse d as f o ll o w s 3 a n a 司 E 4巴 u o nlo A f mm e rsio ntime h Fig 5 H yd ro g e ne vo lut io n r a t eo fth e ba r espee im en the spe eime n w ith di f f u sion e oat in g im m e r s e d in 3 5w tP et N a CI s o lu七ion 一口一 Bar eA Z g j D 一 一Wi thsPutte ring A le o at旧g 山 s A 山 2气 药 门 E 一 8IE 一 7IE 一 6IE 一 5 I A IE4门 E30 0 101 C l 下 Fig 6 P o tentio d y na m ie p o la r iz a t io ne u rv e so f th e b a r e sPe e im e n t h espu tt er i n gAI eo a t e d sPeei m en an d t h e di f f u s i oneo a t e d sPee im en teste d in 3 5w tP et N a CI s o lu tio n m e lt ing ev id enee w asno ti ee da t th e i n t er f a ee b e tw een t h e l i f f u s io neo a t i n g an d t h esu b s t r 就e A eeording to thebinaryAI 一 M gph as e d i a g ra m aneu t ee t i ereac ti on w h i e h eauses th e f o r m舫ion of刀Phase wi l l oeeur a t 43 7 o C U n d er thi sex P er im e n t eon di tio n th e t e m P er a t ureo f v a euu m annea l w as h i g h er t h an t h e m e l七 ing Pointof口phase an d th us 尽Phasew i llbem elted dur ing the annealtreatm ent T hef orma七 io n of七 he liquid p hasew ill le nditselftothef o rmatio n ofalum in umd if f u sio neo ating50 that the su rf a ee m o rP h olog y b eeame smo otha nd den se F igu re4 shows theED X re sults of theligh tP hase a ndtheda rk P ha se res P ee七 iv ely T he alu m in um eo n t en tof the lig htP ha sew a s m u eh h ig h er th an th a七of the da rk Pha se T he e omPo sitio n of the light pha sew a s sim ila rto 刀phase一A llZMgl7 二 M g Z H Z o M g 2 Z O H 一 H 个 l Theref o re t h e m easure dh y o l ro g enevo l u t i onra t eean re P rese 毗the eorrosion r就e ofthe sP eeimen F O rthe bare speeim en i tw as g roun db y S ICp a P er d ur i n gt h e P re P ara ti on whi e hwi llin ev i t a b l y r esu lt i nso m e S IC p ar tiele se mb e ddi n gi n t o th esur f a eeo f s p ee im en T h e e mb e dd e dS ICP ar tiele s asa g a l v a n i ee 就hod e wil l aeee l er 就e the eorrosion of了生 Z91D a lloyinthe e o rr o siv e m edia in aw a y H owev er th ee l ee t r i eeon d ue七 iv ity o f SIC p a rtiele s w a s p o o r its ef f eeto f e atho d e o n 七he eo rro sio n r ate ofb ar e A Z 91D w ill n ot b e seriou s In a d ditio n i n t h i s p a p er th eeorros i onra t eo fb are s P ee im en w as j us七me a su red to eom Pa rew iththat of the spe eimen w iththedif f u sio neo就ing T he results showed that thehydrogen cvolution rate ofthebare speeim n in e r e a s edwit him n l e r sio n tim e Th eslo P eo f t h e lin ew a s n e a rly to1 0 whi e himPl i e d th a tt h eeor ros i onra t eo ft h e b are a l l o yw aseons t a n t H o w ever f o r th es P ee im en wi t hd i f f u s i oneoa ting th e h y d ro g en evo l u ti onr 就ew as redu eed greatly毓theinitialstage b u tt h eeorros i onr 就e in ereased af ter im m ersion f o r 60 h A f t er im m ersion f o r 60 h th eeo ros i onr a t eo f th es P ee im en wi t h d i f f l l s i oneo 毓ing w ash igher than thatoftheba r e sPeeimen whi e h i n d i e 乱edthat some loealarea of dif f u sion eo atii ig was destroyed and the eorrosion of the substr就e was aeeelerated du etothe di而sion eo a t i ngas a ea th o di el a y er F urther i m m er sion th eeorros i onra t e d eerease d re l a t i ve ly d ue t o th eeovera g eo f th eeorros i on p ro d ue twi th h ig hAI eon t en t F r o m th eresu l t o f im m ers io n t es t eo m P are d wi t hth e b ares p ee im en th e d i f f u s i oneoa ti n g f o r m e d b y eo mb i na ti ono f th es P u t匕 eringalum in um a n dth e v a eu u m a n n e al tre a tm ente a n Provide ago odpro七e e tio nf o r AZ91 D alloy in 3 5w t pet N aC Isolutio n T hePola rizatio n eurv e a n d the e o r r o sio n dy na m ieP a r a m ete r sa r esho w n inFig 6 a n d T a ble Z res p ee ti ve l y F r o m T a b l e Z t h eeorros io n P o t en ti a l o f th es P ee im en wi thth e d i而sion eoating was about 一1 2 3 8V s c E whi e hw ass imi l ar t o t h e f r eeeor ros i on p o t en t i a l o f尽phasein v esti gatedby Lunde 云al 10 The eorrosionPoten tialofthe sPeeim en w i七hthedif f u sio n e o就ing was0 338 V higherthanthat ofthe bare AZ 9 1D speeimen A eeording to the eleetroehemieal prin eiP les th e f o r m er w ou ld h a v e l esseorr os i on t en d ene yth an t h e l a tt er Thi seon f o r m s t o t h eresu lt s 乱er Sei T e ehnol V O I 23N o 3 2007 T a bl e 2 D y n a j m ieP a r a m eters d er iv e df r o m t h e P o la ri z a t io ncu r ves W i t h AI eo 就ing V ithdlf f吐sio n eoa t ing 一 14 8 3 一 1 2 38 6 2 5 0 x10 一3 3 9 5 5 x 1 0 一5 o f P o la r iza tio n e ur v e T h ee o r r o sio ne ur r e n t d e nsi t y o f t h espe ei址en w i th thedif f u sion eoating deereased one order of magnitude eom paredw iththat of the ba r e allo y F O rtlle sPeeimen w iththe sPutteringa l u min um eoating t h eeoa t i n g e a l ion ly ae t a s t h e b ar r ie ra tt h e i n i t i a l s t a g e Th es p u t t er i n g eoa ti n g b e g an sea l i n g o f f j u s t a f t er th e m easure m en tw ase a r r ied ou t W h en t h e P o l ar i z 就ion enteredintothe anodiebra n eh th er es id u a l a l uln in u m eo 就ing aetedasthe ea t hode w h i e h acee l er 就ed the eorrosion ofthe substrate T he a b ove results verif ied that the single sPutteringa l u min um eoatingeouldn ot Provide Proteetio ntothe substr歌e 1 1 1 addition aeeordin g to researeh results bySonga j nd Atrens 3 that口phase servesadualef f e et in eorrosion ofAZ91Dm 鳃nesi um a l loys 刀Phase ean aeteither a s a ba r rier or as agalv anie ea t liode T he ef f eetof 口Phase on the eorrosion of A Z91D al loy 15 dePende武 on i tsdistribution a n d volume f r aetion l f it 15Presen ed as a smallf ra etion i t serves m a i n ly asa g a l t t a n i eea th o d e an d ae ce l era t es t h eover a ll eorr o s io n O f a m a t r i xH o w ever ifi t s f r ae t i on 1 5 h ig h enou g h i t m a v ae七 ma i n lv asajl allo dieba r rier a g a i n st the o v era llco rro sio not tnealloyL 勺0 I tl l as a g r e 毓 poten tia l七0imp r娜ethe eorrosion resistanee ofma名 n esiu ma llo y sthro ugh t砍i ngf u l lad v a n ta g eof尽Phase ProPerties ofAZ91D a lloy T he adhesion streng th ofthedlf f llsion eoating w i th the substr乱ewas enhan eed Thedif f u sion eoa t ing was eomPo sed of 尽Phase w h ic h f o r m e d aeon t in uous m a t r i x an d a d a j r k Ph ase wi t hl o w a l u m i nu m eon t en t