Phase Formation through a Stage of Liquid State in Metallic Materials Being Electrodeposited: Recent Experimental Proofs

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1 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 Phse Formtion through Stge of Liqui Stte in Metlli Mterils Being Eletroeposite: Reent Experimentl Proofs Oleg B. Girin Deprtment of Mterils Siene, Ukrinin Stte University of Chemil Tehnology, Prospekt Ggrin 8, Dnipropetrovsk 49005, Ukrine girin@u.fm Astrt The effet of inrese of ensity of metls eing eletroeposite uner the influene of entrifugl fore ting perpeniulr to the rystlliztion front is foun. Wve -like flow of surfe lyers of metls eing eletroeposite uner the influene of entrifugl fore ting prllel to the rystlliztion front, s well s ening of wves y mehnil hinrnes n formtion of fom on the rests of wves re isovere. Chnge of form of the eposits of metls eing eletroeposite uner the influene of entrifugl fore inluing the growth of length n thikness of the eposits t the iretion of fore tion with moifition of their onfigurtion epening on overlo vlues is isovere. Preominnt evelopment of eposits of metls eing eletroeposite eyon the ege of the thoe in the iretion of the tion of entrifugl fore prllel to the rystlliztion front is foun. The otine results prove the vliity of the isovere phenomenon of phse formtion through stge of liqui stte in metlli mterils eing eletroeposite. Keywors Phse Formtion; Eletroeposite Metl; Liqui Stte; Centrifugl Fore; Density; Surfe Morphology Introution The phenomenon of phse formtion through stge of liqui stte in metlli mterils eing eletroeposite ws theoretilly preite in 1986 [1] n in 1988 it ws experimentlly foun [2]. The essene of the isovere phenomenon is tht uring the eletrohemil eposition of metlli mteril onto soli thoe in n queous meium superoole metlli liqui is eing forme n soliifie t the eposition temperture in the form of rystlline or/n n morphous phse. In the work [3] it is shown tht liqui stte of metlli mteril eing eletroeposite is use y very quik (explosive) hrter of its formtion s result of hin retion of eletrohemil formtion of toms. At tht uring one t of explosive growth toms re eing forme on verge. With regr to very quik pssge of the t of explosive growth (out 10 7 se), the toms hve no time to form struture with long-istne orer of their rrngement. Multitue of suh lusters of toms re eing forme in vlnhe-like mnner in vrious ples on the surfe of the thoe or the growing eposit n then eing omine into lrger formtions onstitute liqui phse of metlli mteril eing eletroeposite. The two spets shoul e mentione. First, liqui eing forme uring eletroeposition of metlli mteril is lwys superoole. Seon, liqui of metlli mteril eing eletroeposite is onsequene of its high-energy ut not hightemperture stte s in onventionl melts. During reent yers mny experimentl results proving the vliity of this phenomenon were otine [4-9]. The gol of this work ws the further experimentl proof of the vliity of the isovere phenomenon. Experimentl Proof of Vliity of the Phenomenon Ie One n Its Reliztion It is known tht uring the entrifuging of liqui metlli mteril ue to the tion of entrifugl fore it presses itself to the wlls of rotting moul, eomes enser n rystllizes in more ompt ingot (so lle entrifugl sting). Therefore, if uring eletrorystlliztion metlli mteril relly psses through stge of liqui stte, then s result 108

2 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 of entrifugl fore ting perpeniulr to the rystlliztion front it shoul e expete the formtion of n eletroeposit, whih is enser in omprison with n eletroeposit otine uner orinry onitions. For the otining of metls eing eletroeposite in the fiel of entrifugl fore, the unit ws evelope n onstrute [10]. The unit provie the tion of entrifugl fore proportionl to the norml elertion kg (where k overlo oeffiient) rnging from 1 g to 1256 g. The vlues of entrifugl fore ws hnge stepwise y vrying the numer of rottions of the entrifuge rotor from 0 to 3000 rottions per minute with the step of 500, whih resulte in the norml elertion of 1 g, 35 g, 140 g, 314 g, 558 g, 872 g n 1256 g. The unit llowe influening y entrifugl fore on metl eing eletroeposite oth perpeniulr n prllel to the rystlliztion front epening on the eletroes positions in the eletrohemil ell. Constrution fetures of the entrifuge n the eletrohemil ells ompletely eliminte possiility of eletrolyte flow reltively to the thoe uring eletroeposition of metls [10]. During the opertion of entrifuge the ells rotte horizontlly jointly with the rotor. The thoe ws mounte on the ottom of the ell perpeniulr to its xis, thus uring rottion of the ell the thoe ws perpeniulr to the rotor rius. As entrifugl fore uring rottion is lwys irete long with the rotor rius from its enter, suh position of the thoe provie fore influene on metl is eletroeposite perpeniulr to the rystlliztion front. In orer to eliminte the influene of hyrogen on the ensity of eposits eing forme in the fiel of entrifugl fore, the investigtions were performe on smples of opper n nikel eing eletroeposite with the urrent yiel vlues of % (Tle 1). The urtion of otining of eh smple ws 60 min. In orer to voi the reution of onentrtion of metl ions in the eletrolytes uring eletroeposition, the solule noes were use. Density of opper n nikel eletroeposits ws etermine y the metho of hyrostti weighing. As result of the omplete investigtions, it ws foun tht the influene of entrifugl fore on metls ws eletroeposite perpeniulr to the rystlliztion front uses inrese of their ensity (Fig. 1). TABLE I ELECTROLYTES COMPOS ITION AND PARAMETERS OF DEPOSITION OF METALS IN THE FIELD OF CENTRIFUGAL FORCE Metl Eletrolytes Eletrolyte Current Current Composition, g L -1 Temperture, Density, Yiel, С A m -2 % Cu CuSO4 5H2O H2SO4 50 Ni NiSO4 7H2O NiCl2 6H2O 50 H3BO3 35 C11H23COON 0.1 FIG. 1 CHANGE OF DENSITY OF COPPER (1) AND NICKEL (2) BEING ELECTRODEPOSITED DEPENDING ON THE OVERLOAD COEFFICIENT Chrter of the influene of the overlo on the ensity of the investigte metls is the sme: growth of k vlue up to 314 use s signifint inrese of ensity n susequent growth of k vlue up to 1256 results in minor inrese of ensity of metls. The most rupt inrese of metls ensity (from 8.76 to 8.88 g m -3 for opper n from 8.62 to 8.72 g m -3 for nikel) ws foun uring low overlos (uner k = 139). The otine result n e expline y tightening of liqui phse eing forme uring eletrohemil eposition of metls. A possiility of otining of more ense metls y their eletroeposition in the fiel of entrifugl fore in omprison with metls otine uner orinry onitions inites tht metls uring eletrohemil eposition relly pss through stge of liqui stte. Thus, the foun effet of inrese of ensity of metls eing eletroeposite uner the influene of 109

3 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 entrifugl fore irete perpeniulr to the rystlliztion front onfirms the vliity of the isusse phenomenon. Ie Two n Its Reliztion It is known tht liqui metlli mteril in ontrst to soli one is le to flow i.e. to move its mss in the iretion of tion of the pplie fore. Therefore if metlli mteril uring eletrohemil eposition relly psses through stge of liqui stte, then uner the influene of entrifugl fore prllel to the rystlliztion front it shoul e expete the movement of its mss y the wve-like flow of ontinuously replenishing liqui surfe lyers. Inee, the fore influene on the ontinuously forming liqui surfe lyers of mteril eing eletroeposite will use osillting motion of liqui surfe whih in turn will result in formtion of wves. The investigtions were performe on smples of nikel n opper eletroeposite in the fiel of entrifugl fore. The thoe ws mounte in the ell prllel to its xis, therefore uring the rottion of the ell, the thoe ws prllel to the rotor rius whih provie fore influene on metl eing eletroeposite prllel to the rystlliztion front. Due to the m etl urrent yiel vlues % n impossiility of eletrolyte motion reltive to the thoe in the ell uring eletroeposition [10], the influene of hyrogen n eletrolyte motion on surfe morphology were ompletely eliminte. As result of the omplete investigtions, the effet of wve-like flow of surfe lyers of metls eing eletroeposite in the iretion of tion of entrifugl fore ws foun. The most oviously soliifie wves were fixe on the surfe of nikel eletroeposits otine t the fore influene proportionl to 1256 g (Fig. 2). Thus t the sene of entrifugl fore the surfe of nikel eposits is smooth n oes not ontin wvelike forms (Fig. 2 ), ut s result of signifint overlo the surfe of eposits of nikel eing eletroeposite ontins soliifie wves (Figs. 2 - ). Suh surfe morphology is result of soliifition of surfe lyers of nikel eing eletroeposite whih re in liqui stte n prtiipte in wve-like motion uner the influene of entrifugl fore prllel to the rystlliztion front. FIG. 2 SCANNING ELECTRON MICROSCOPY IMAGES OF NICKEL ELECTRODEPOS ITS DEMONS TRATING WAVE-LIKE FLOW OF SURFACE LAYERS OF NICKEL BEING ELECTRODEPOSITED UNDER THE INFLUENCE OF A CENTRIFUGAL FORCE PROPORTIONAL TO ACCELERATION OF 1 G (A INITIAL CONDITION) AND 1256 G (B-D) THE FORCE IS DIRECTED FROM TOP TO BOTTOM There re two min fetures of wve-like flow of surfe lyers of metls eing eletroeposite. First, metlli wves re ent y mrosopi efets suh s soli inlusions (Fig. 2 ) or through pores (Figs. 2, ). Suh ening of wves y mehnil hinrnes is typil for liqui mteril with high visosity. Assume tht mteril eing eletroeposite is in soli stte only (e.g. s fine soli prtiles), then in tht se pores woul e fille with prtiles n there woul e vities roun soli inlusions use y url-like motion of prtiles. In Fig. 3, typil imges of metlli wves ent y through pore n y soli inlusion s well s struture of wves nery the mentione hinrnes re presente. As it is seen in Fig. 3, wve-like res of mteril hve form of semiirulr terres n ontin prtiles of gloulr form whih re seemingly soliifie lusters or groups of lusters of mteril. Another typil feture proving the origin of wvelike forms from soliifition of metlli liqui moving uner the influene of entrifugl fore is the formtion of fom on the rests of wves. Thus in Figs. 3, the res of soliifie fom forme on the rests of wves s result of mehnil ispersion of metlli liqui uner fore influene re seen. 110

4 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 Fig. 4 lerly proves the existene of fom forme uring wve-like flow of liqui surfe lyer of nikel eing eletroeposite n frozen s result of its very quik soliifition. Inee, ssume tht wvelike flow of surfe lyer of metl eing eletroeposite uner the influene of entrifugl fore is use y the movement of fine soli prtiles, then fter the en of the proess the fom shoul not exist n metl shoul e not in monolithi ut in power form. FIG. 3 SCANNING ELECTRON MICROSCOPY IMAGES OF NICKEL ELECTRODEPOSITS SHOWING WAVES BENT BY A PORE (A,C) AND BY AN INCLUSION (B,D) THE FORCE PROPORTIONAL TO ACCELERATION OF 1256G IS DIRECTED FROM TOP TO BOTTOM As t minor vlues of entrifugl fore soliifie wves hve wie rests, the morphology of fom res ws investigte on the smples of nikel eposits otine t minor fore influene (proportionl to 35 g n 140 g). As it is seen in Fig. 4 soliifie fom is glssy formtions of vrious onfigurtions poorly here to the se. Thus in Figs. 4,, the res of the rests of wves of nikel eposits with prtilly peele off frgments of soliifie fom s result of its rking re lerly seen. The lyer of glssy fom is thin enough for oting struture to e seen through it (Figs. 4, ). The ifferenes in onfigurtions of metlli wves of eletroeposite opper n nikel uner the influene of entrifugl fore re use y orse struture of opper. At the sme time, the min fetures of pst liqui stte retin. The first one is wve-like flow of its surfe lyers, the seon one is ening of wves y mehnil hinrnes (lrge gloules n their groups) n the thir one is the pperne of soliifie fom on the rests of wves. One of the results proving the vliity of the isusse phenomenon is wve-like re of soliifie fom foun on surfe of opper eletroeposit (Fig. 5 ). The vrious frgments of this fom wve re shown in Figs. 5 - lerly emonstrte the onsequenes of pssing through stge of liqui stte y opper eing eletroeposite. Thus, wve-like flow of surfe lyers of metls eing eletroeposite uner the influene of entrifugl FIG. 4 SCANNING ELECTRON MICROSCOPY IMAGES OF NICKEL ELECTRODEPOSITS WITH FRAGMENTS OF SOLIDIFIED FOAM ON THE CRESTS OF WAVES THE FORCE PROPORTIONAL TO ACCELERATION OF 35G (A,C) AND 140G (B,D) IS DIRECTED FROM TOP TO BOTTOM FIG. 5 SCANNING ELECTRON MICROSCOPY IMAGES OF COPPER ELECTRODEPOS IT DEMONS TRATING SOLIDIFIED WAVE-LIKE FOAM (A) AND FRAGMENTS OF ITS VARIOUS AREAS (B-D) THE FORCE PROPORTIONAL TO ACCELERATION OF 314G IS DIRECTED FROM TOP TO BOTTOM 111

5 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 fore ting prllel to the rystlliztion front s well s ening of wves y mehnil hinrnes n formtion of fom on the rests of wves prove the vliity of the isovere phenomenon. to k = 35 the fr ege of the eposit eme thiker n this ulge h form of spheril segment long the ege of the thoe (Fig. 6 ). Ie Three n Its Reliztion It is known tht metlli mteril in liqui stte in ontrst to mteril in soli stte possesses very low sher strength. Hene, liqui metlli mteril is priniplly ifferent from soli one y its ility to hnge its form uner the influene of n ting fore. Therefore, if uring eletrohemil eposition metlli mteril relly psses through stge of liqui stte, then uner the influene of entrifugl fore ting prllel to the rystlliztion front it shoul e expete hnge of form of the eposit in the iretion of the fore tion. Inee, s result of the soliifition of the metlli liqui, shifte reltive to the thoe, inrese of length n thikness of the eposit s well s hnge of its onfigurtion in the iretion of n ting fore re quite prole. For the reliztion of this ie, hnge of form of eposits of opper n nikel eing eletroeposite uner the influene of entrifugl fore ting prllel to the rystlliztion front ws investigte. The thoe ws mounte in the ell prllel to its xis, therefore uring rottion of the ell the thoe ws prllel to the rotor rius, whih provie fore influene on metl eing eletroeposite prllel to the rystlliztion front. Thin pltes of nikel (for opper eposition) n opper (for nikel eposition) were use s the thoe. Due to urrent yiel of metl of 99.5%~ 100 % n impossiility of eletrolyte motion reltive to the thoe in the ell uring eletroeposition [10] the influene of hyrogen formtion n eletrolyte motion on form of metl eposits ws ompletely eliminte. A hnge of form of eposits of metls eing eletroeposite ws ontrolle y omprison of eletron mirosopy imges of the fr ege of eposits in the iretion of tion of entrifugl fore. As result of the omplete investigtions, it ws foun hnge of form of the eposits of metls eing eletroeposite uner the influene of entrifugl fore ting prllel to the rystlliztion front (Fig. 6). Thus uner usul eletroeposition onitions, i.e. when the rotor is t rest (k = 1), the fr ege of opper eletroeposit ws level n somewht urve to the thoe surfe (Fig. 6). With n inrese of overlo e FIG. 6 SCANNING ELECTRON MICROSCOPY IMAGES OF THE FAR EDGE OF COPPER DEPOSITS ILLUSTRATING A CHANGE OF THEIR FORM DURING ELECTRODEPOSITION UNDER THE INFLUENCE OF A CENTRIFUGAL FORCE PROPORTIONAL TO ACCELERATION OF 1 G (A) INITIAL CONDITION, 35 G (B), 140 G (C), 558 G (D), 872 G (E) AND 1256 G (F) THE FORCE IS DIRECTED FROM TOP TO BOTTOM The oserve hnge of form of opper eposit is expline y the ft tht forming lusters of opper eing eletroeposite n eing in liqui stte or their formtions move towr the ege of the thoe uner the influene of entrifugl fore. Ahesion fore of opper lusters eing soliifie n the thoe (or n lrey soliifie eposit re) seemingly is greter thn the vlue of entrifugl fore. Therefore the influene of minor entrifugl fore, irete prllel to the rystlliztion front, on metl eing eletroeposite uses minly thikening of eposit ege. The further inrese of overlo to k = 140 uses eformtion of the ulge ege of eposit in the iretion of tion of the fore n formtion of f 112

6 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 evient eposit res going eyon the ege of the thoe (Fig. 6 ). Drsti hnge of form of the opper eposit ours fter the inrese of overlo to k = 558 (Fig. 6 ). At this overlo otryoil eposit res pper eyon the ege of the thoe in the iretion of the tion of the fore. formtion of more rnhe n relief res of opper eing eletroeposite eyon the ege of the thoe (Fig. 7 ). At overlos of k = 558 n 872 the size of prtiles of the res ereses, they eome flttene n gin more ifferentite struture (Fig. 7 ). The otine form of the eposit is expline y the ft tht t k = 558 entrifugl fore is seemingly greter thn hesion fore of opper lusters eing soliifie n the thoe (or lrey soliifie re of the eposit). As result of the influene on opper, uring its eletroeposition y entrifugl fore of signifint vlue prllel to the rystlliztion front, the essentil shift of ontinuously replenishing liqui opper lusters or their formtions reltive to the eposit surfe ours. Soliifition of ontinuously forming liqui phse eing uner fore influene uses oth the evelopment of lrey existing eposit res eyon the ege of the thoe n the formtion of new res. The onept of metls eing eletroeposite pssing through stge of liqui stte is lerly prove y the further hnge of form of eposits of opper eing eletroeposite with the inrese of entrifugl fore. As it is seen in Fig. 6 e, the inrese of fore influene to the overlo of k = 872 on opper eing eletroeposite results in growth n rnhing of the eposit res going eyon the ege of the thoe. The results of n experiment on the influene of entrifugl fore proportionl to elertion of 1256 g on opper eing eletroeposite re espeilly impressive. Fig. 6 f inites tht the fr ege of opper eposit in the iretion of suh fore influene hnge its form funmentlly reltive to the initil one (Fig. 6 ). Thus the ege of opper eposit ontins grown enrite res going fr eyon the ege of the thoe oth in the iretion of the tion of the fore n in the other iretions (Fig. 6 f). The nlysis of morphology of eposit res going eyon the ege of the thoe in the iretion of the tion of the fore (Fig. 7) shows tht uner minor overlo (k = 35) these res onsist of soliifie hlfroun rops forme y mny fine gloulr lusters formtions (Fig. 7, ). With the inrese of overlo to k = 140 gloulr form of the eposit surfe retins ut the res going eyon the ege of the thoe otin elongte form. The further inrese of overlo to k = 314 uses FIG. 7 SCANNING ELECTRON MICROSCOPY IMAGES OF THE FAR EDGE OF COPPER DEPOS ITS SHOWING MORPHOLOGY OF THE AREAS GOING BEYOND THE EDGE OF THE CATHODE DEPOSITS WERE OBTAINED BY ELECTRODEPOSITION UNDER FORCE INFLUENCE PROPORTIONAL TO ACCELERATION OF 35 G (A), 314 G (B), 872 G (C) AND 1256 G (D). THE FORCE IS DIRECTED FROM TOP TO BOTTOM. Eletroeposition of opper t gret fore overlos (k = 1256) results in funmentl hnge of morphology of eposit res going eyon the ege of the thoe. The size of prtiles of these res ereses signifintly, they gin isk-like n spinle-like forms, their growth ours in vrious iretions. Thus in the enter of Fig. 7, it is shown eposit re eyon the ege of the thoe eveloping towrs fore influene. The foun effet of form hnge of eposits of opper eing eletroeposite uner the influene of entrifugl fore is ompletely prove y the nlysis of the fr ege of nikel eposits otine uner vrious fore influenes uring their eletroeposition (Fig. 8). Aoring to the otine results, fore influene on nikel eing eletroeposite uses the growth of length n thikness of the eposits t the iretion of fore tion with moifition of their onfigurtion epening on overlo vlues. Thus uner minor overlo (k = 35) the isusse hnge of form is seen s thikening of the ege of 113

7 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 nikel eposit (Fig. 8 ). Suh spheril segment ulge is more ler-ut thn similr one of opper eposit (Fig. 6 ). Seemingly it n e expline y finer rystl struture of nikel eing eletroeposite in omprison with opper struture. eome more essentil, ut the generl teneny of ifferentition of struture of the res going eyon the ege of the thoe remins (Fig. 9 n Fig. 7 ). FIG. 9 SCANNING ELECTRON MICROSCOPY IMAGES OF THE FAR EDGE OF NICKEL DEPOSITS SHOWING MORPHOLOGY OF THE AREAS GOING BEYOND THE EDGE OF THE CATHODE DEPOSITS WERE OBTAINED BY ELECTRODEPOSITION UNDER FORCE INFLUENCE PROPORTIONAL TO ACCELERATION OF 140G (A) AND 314G (B). THE FORCE IS DIRECTED FROM TOP TO BOTTOM FIG. 8 SCANNING ELECTRON MICROSCOPY IMAGES OF THE FAR EDGE OF NICKEL DEPOS ITS DEMONS TRATING A CHANGE OF THEIR FORM DURING ELECTRODEPOSITION UNDER THE INFLUENCE OF A CENTRIFUGAL FORCE PROPORTIONAL TO ACCELERATION OF 1G (A) INITIAL CONDITION, 35G (B), 314G (C) AND 872G (D) THE FORCE IS DIRECTED FROM TOP TO BOTTOM The further hnge of form of eposit of nikel eing eletroeposite with the inrese of overlo is seen s grul growth of its length in the iretion of the tion of entrifugl fore (Fig. 8 ). Fig. 8 illustrtes new form of nikel eposit otine s result of signifint fore influene (k = 872) prllel to its rystlliztion front uring eletroeposition. There is lyer of soliifie liqui phse of nikel m thik eyon the opper thoe long its ege. Multilyer formtions in the iretion of the tion of the fore, smooth relief n gloulr ulges of this grown lyer prove the ft of its formtion y soliifition of metlli liqui wve-like lyers. As result of soliifition of metlli liqui phse, the res of nikel eposits going eyon the ege of the thoe in the iretion of the fore influene n e onsiere (Fig. 9). It shoul e mentione tht morphologies of the res of eposits of metls (nikel n opper) eing eletroeposite uner minor fore influene iffer insignifintly (Fig. 9 n Fig. 7 ). With the inrese of overlo, the ifferenes of morphologies of the res of nikel n opper A feture of onfigurtion of nikel eposits uner fore influene prllel to their rystlliztion front is wve-like form of the fr ege of the eposit t the iretion of entrifugl fore tion (Fig. 10 ). This form of the ege of the eposit is similr to wve-like form of the ege of opper eposit (Fig. 10 ). However, it is forme not s result of growth of enrite res ut ue to the gthering of gloulr prtiles t the ege of the eposit. In Fig. 10, it is lerly seen tht some gloulr prtiles re ingrown in nikel mtrix whih is n inition of its soliifition from liqui stte. This ingrowing effet intensifies t high overlos. FIG. 10 S CANNING ELECTRON MICROSCOPY IMAGES OF THE FAR EDGE OF NICKEL (A) AND COPPER (B) DEPOSITS ILLUSTRATING FEATURES OF THEIR CONFIGURATION UNDER FORCE INFLUENCE PROPORTIONAL TO ACCELERATION OF 140G (A) AND 1256G (B) THE FORCE IS DIRECTED FROM TOP TO BOTTOM It shoul e mentione tht with the inrese of overlo uring metls eletroeposition, the quntity of glssy frgments of soliifie fom ingrown in the eges of the res eyon the thoe inreses (Fig. 6, -f; 7, -; 8,, ; 9, n 10, ). Nikel eposits in ontrst to opper ones ontin suh inlusions not 114

8 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 only in the eges ut lso on the surfe of the res ner the eges. For exmple the glssy inlusions prtilly ingrown in nikel mtrix re shown t Fig. 11. FIG. 11 S CANNING ELECTRON MICROSCOPY IMAGES OF GLASSY INCLUSIONS ON THE SURFACE OF NICKEL ELECTRODEPOSITS CENTRIFUGAL FORCE IS PROPORTIONAL TO ACCELERATION OF 314G (A) AND 872G (D) AND DIRECTED FROM TOP TO BOTTOM. Thus, hnge of form of metls eletroeposits uring their eletrohemil eposition uner fore influene prllel to the rystlliztion front proves tht metlli mterils eing eletroeposite pss through stge of liqui stte. Ie Four n Its Reliztion Assume tht metlli mteril uring eletrohemil eposition relly psses through stge of liqui stte, then uner the influene of entrifugl fore prllel to the rystlliztion front on the lusters of toms, whih hve not yet forme three-imensionl lttie typil for rystl stte, it shoul e expete their movement t some istne t the iretion of the fore tion. As result of suh movement, the omintion of the lusters of toms into lrger formtions (so lle miro-roplets) will e esier. Suh miro-roplets will form lyers of liqui phse ontinuously replenishing uring eletroeposition. At the inrese of mss n size of liqui lyers their shift in the iretion of tion of entrifugl fore will inrese. If the isusse phenomenon is vli, then t signifint vlue of entrifugl fore ting prllel to the rystlliztion front it shoul e expete the movement of liqui lyers towr the ege of the thoe n then eyon the ege of the thoe n next eyon the ege of previous soliifie lyers of metls eing eletroeposite. This will use preominnt evelopment of eposit of metl eing eletroeposite eyon the ege of the thoe in the iretion of the fore tion. For the investigtion of fetures of formtion of the eposits of opper n nikel their ross-setions long the iretion of entrifugl fore tion were prepre. The eposits, otine in the entrifuge uner similr onitions ut when the rotor ws t rest (i.e. t k = 1), were use s referene smples. As result of omplete investigtions, the effet of preominnt evelopment of eposits of metls eing eletroeposite eyon the ege of the thoe t the iretion of the fore tion prllel to the rystlliztion front ws foun. Thus, in Fig. 12, it is seen tht the ege of opper eposit, otine uner usul onitions on thin nikel thoe hs lmost the sme thikness on ll its res. At tht the ege of opper eposit peele off the en of the thoe ue to low hesion (peeling spot is shown y n rrow). FIG. 12 SCANNING ELECTRON MICROSCOPY IMAGES OF THE CROSS -SECTION OF THE FAR EDGE OF COPPER DEPOSITS ALONG THE ACTION OF A CENTRIFUGAL FORCE PROPORTIONAL TO ACCELERATION OF 1G (A) INITIAL CONDITION AND 872G (B), DEMONSTRATING THE EFFECT OF DEVELOPMENT OF THE DEPOSITS OF METALS BEING ELECTRODEPOSITED BEYOND THE EDGE OF THE CATHODE UNDER THE FORCE INFLUENCE THE FORCE IS DIRECTED FROM THE RIGHT TO THE LEFT The imge of ross-setion of the ege of opper eposit forme uner the influene of entrifugl fore of signifint vlue (Fig. 12 ) lso inites peeling off the ege of the eposit t the en of the thoe (peeling spot is shown y n rrow). But form of the ege of this eposit is signifintly ifferent from the ege of usul eposit. The ifferene is the growth of its length y more thn 100 µm long the fore tion (Fig. 12 ). Suh result inites tht opper eposit uring its eletroeposition ws eveloping uner the influene of entrifugl fore eyon the ege of the thoe. If to ompre thikness of the eposits eletroeposite in the fiel of entrifugl fore t vrious istnes from the fr ege of the thoe, signifint thikening of the eposits in the iretion of the fore tion is ovious. Thus uner usul onitions of eletroeposition thikness of opper eposit t vrious istnes from the fr ege of the thoe is lmost the sme n equl to 10 µm (line 1 t Fig. 13). 115

9 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 It shoul e mentione tht wve-like flow of surfe lyers of metls eing eletroeposite is the min motion of their liqui phse uner the influene of entrifugl fore. Though, esies wve-like flow of lyers of metls eing eletroeposite (Fig. 15 ) overflow of lyers (Fig. 15 ), their foming (Fig. 15 ) n ripples on their surfe (Fig. 15 ) our epening on vlues of overlo. FIG. 13 CHANGE OF THICKNESS OF ELECTRODEPOS ITED COPPER DEPOS ITS (L) WITH AN INCREASE OF THE DISTANCE FROM THE FAR EDGE OF THE CATHODE (L) DEPOSITS WERE OBTAINED UNDER THE ACTION OF A CENTRIFUGAL FORCE PROPORTIONAL TO ACCELERATION OF 1G (1) INITIAL CONDITION AND 1256G (2) Uner the tion of entrifugl fore the eposits eing eletroeposite thiken signifintly towr the ege of the thoe t the iretion of the fore tion (urve 2 t Fig. 13). Thus t the istne of 6800~1840 µm from fr ege the thikness of the eposit otine t overlo of k = 1256 is just 1.58~ 2.55 µm, n with erese of l vlues to 800 n 230 µm the eposit thikens up to 4.88 n 9.09 µm respetively. An t the minimum istne from the fr ege of the thoe (20 µm) the vlue of thikness of this eposit is two times s lrge s respetive vlue of the eposit otine uner usul onitions (Fig. 13). Suh signifint thikening of the eposits t the iretion of the tion of entrifugl fore n e expline y the omintion of the lusters of toms, whih re in liqui stte, in miro-roplets forming lyers whih move metl eing eletroeposite towr the ege of the thoe in wve-like mnner. Thus s n exmple in Fig. 14, metlli wves forme on the surfe of the eposit of opper eing eletroeposite t overlo of k = 1256 re shown. FIG. 14 SOLIDIFIED WAVES OF LIQUID PHASE OF COPPER DEPOSIT BEING ELECTRODEPOSITED UNDER THE INFLUENCE OF A CENTRIFUGAL FORCE ACTING PARALLEL TO THE CRYSTALLIZATION FRONT WITH ACCELERATION PROPORTIONAL TO 1256G: A SIDE VIEW (THE FORCE IS DIRECTED FROM THE RIGHT TO THE LEFT), B TOP V IEW (THE FORCE IS DIRECTED FROM TOP TO BOTTOM) At Fig. 15 gloulr soli prtiles of opper eposit, moving uner the influene of entrifugl fore towr the ege of the thoe, re seen. With n inrese of overlo the size of prtiles, move reltive to the eposit surfe, inreses signifintly. Ingrowth of prtiles in the mtrix (Fig. 15, ) n onfigurtion of the vnt ples, tht were previously oupie y suh prtiles (Fig. 15 ), inites soliifition of opper mtrix from liqui stte. Similr results were lso otine uring investigtions of evelopment fetures of nikel eposits eing eletroeposite eyon the ege of the thoe in the iretion of the fore influene. Therefore, preominnt evelopment of eposits of metls eing eletroeposite eyon the ege of the thoe in the iretion of the tion of entrifugl fore prllel to the rystlliztion front is suffiient onfirmtion of the vliity of the isusse phenomenon. Thus, the otine results prove the vliity of the phenomenon of phse formtion through stge of liqui stte in metlli mterils eing eletroeposite. Conlusions The foun effet of inrese of ensity of metls eing eletroeposite uner the influene of entrifugl fore irete perpeniulr to the rystlliztion front onfirms the vliity of the phenomenon of phse formtion through stge of liqui stte in metlli mterils eing eletroeposite. Wve-like flow of surfe lyers of metls eing eletroeposite uner the influene of entrifugl fore ting prllel to the rystlliztion front s well s ening of wves y mehnil hinrnes n formtion of fom on the rests of wves prove the vliity of this phenomenon. Chnge of form of the eposits of metls eing eletroeposite uner the influene of entrifugl fore inluing the growth of length n thikness of the eposits t the iretion of fore tion with moifition of their onfigurtion epening on 116

10 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 overlo vlues prove the vliity of the isovere phenomenon. Preominnt evelopment of eposits of m etls eing eletroeposite eyon the ege of the thoe in the iretion of the tion of entrifugl fore prllel to the rystlliztion front onfirms the vliity of the isusse phenomenon. FIG. 15 S CANNING ELECTRON MICROSCOPY IMAGES OF THE SURFACE OF COPPER DEPOSITS BEING ELECTRODEPOSITED UNDER THE INFLUENCE OF A CENTRIFUGAL FORCE, ILLUSTRATING MORPHOLOGY OF SOLIDIFIED LIQUID PHASE DEPENDING ON OVERLOAD VALUE: A AND B OV ERLOAD IS 1256, C AND D 558 THE FORCE IS DIRECTED FROM TOP TO BOTTOM Referenes [1] O. B. Girin n G. M. Voro ev, Regulr Chnge of Sustruture of Eletroeposite Metls with the Inrese of the Nuler Chrge of their Atoms, Zhurnl Vsesoyuznogo Khimiheskogo Oshhestv imeni D.I. Meneleev, 1986, vol. 31, pp (In Russin). [2] O. B. Girin n G. M. Voro ev, Chnge of Diffrtion of X-Rys Dissipte y Metls uring their Eletrolyti Deposition, Zhurnl Fiziheskoi Khimii, 1988, vol. 62, pp (In Russin). [3] O. B. Girin, Phenomenon of Preipittion of Metl Being Eletroeposite, Ourring vi Formtion of n Uneroole Liqui Metl Phse n its Susequent Soliifition. Prt 1. Experimentl Detetion n Theoretil Grouning, Mterils Development n Proessing, 2000, vol. 8, pp [4] O. B. Girin, Phenomenon of Preipittion of Metl Being Eletroeposite, Ourring vi Formtion of n Uneroole Liqui Metl Phse n its Susequent Soliifition. Prt 2. Experimentl Verifition, Mterils Development n Proessing, 2000, vol. 8, pp [5] O. B. Girin, Phenomenon of Struture Formtion of Metls eing Eletroeposite vi Superoole Metl Liqui, n its Use for the Development of Avne Tehnologies of Depositing New Types of Protetive Composite Cots on Cnne Foo Steel Sheet, in Pro. AFES 2004, Pris, 2004, pp [6] O. B. Girin, Struture Formtion of Metls eing Eletroeposite through Metl Liqui s Tool for Surfe Qulity Upgring of Cnne Foo Steel Sheet, in Pro. AFES 2005, Hong Kong, 2005, pp [7] O. B. Girin, Phse Trnsformtions in the Metlli Mterils eing Eletroeposite, in Pro. AFES 2006, Dvos, 2006, pp [8] O. B. Girin, Phse Trnsformtions in the Metlli Mte rils eing Eletroeposite n Their Applition for the Development of Avne Tehnologies for Antiorrosive Protetion of Cnne-Foo Steel Sheet, Mterils Siene Forum, 2007, vol , pp [9] O. B. Girin, Phse n Struture Formtion of Metlli Mterils Eletroeposite vi Liqui Stte Stge: New Experimentl Proof, Defet n Diffusion Forum, 2010, vol , pp [10] O. B. Girin n I. D. Zkhrov, Inrese of Density of Metls eing Eletroeposite Uner the Influene of Centrifugl Fore, Vostohno-Evropeiskii zhurnl pereovykh tekhnologii, 2011, 5/5, pp. 4 7 (In Russin). Oleg B. G ir in w s orn in Dnipropetrovsk region, Ukrine in In 1974 he grute with honors from tehnologil fulty of Dnipropetrovsk Metllurgil Institute n strte his postgrute ourse. In 1977 he omplete the post-grute ourse, n in 1990 he of the sheule his otorte ourse t this institution efening his otorte s isserttion y speilty of Physil Metllurgy n Het Tretment of Metls. He hs PhD (1981) n DS (1991) e grees, ertifites of Senior Reserh Fellow (1992) n Professor (2002). 117

11 Interntionl Journl of Mteril Siene Vol. 2 Iss. 4, Dee me r 2012 During he worke t Dnipropetrovsk Metllurgil Institute s junior ( ), senior ( ) n leing reserh fellow ( ). Sine 1998 he hs een working t Ukrinin Stte University of Chemil Tehnology s the HEAD OF THE MATERIALS SCIENCE DEPARTMENT, tht ws estlishe with his iret involvement, n sine 2010 s the VICE-RECTOR OF SCIENCE. Min iretions of his sientifi tivity re the investigtion of lws of struture formtion of metlli mterils n the evelopment of vne tehnologies for otining of otings with enhne properties. Uner his sientifi supervision the vne tehnologies for prouing new types of protetive otings on metl-roll were evelope n the speil-property omposite film mterils were rete. He otine priority results in investigtions of influene of nnorystl, morphous n oriente struture on the properties of eletrohemil otings. Prof. Girin hs won worlwie reognition s sientist. Uner sientifi supervision of Prof. Girin n with his involvement three interntionl ompetitions of R&D projets finne y the governme nts of the USA, Cn n the Europen Union hve een won. He hs een elete s n tive memer of the New-York Aemy of Sienes (1997), TMS (1995), ASM (2004) n ECS (2005). For the outstning ontriution to eletrohemil mterils siene n unique evelopments in the fiel of speil mterils siene Prof. Girin ws wre with The Interntionl Einstein Awr for Sientifi Ahievement (Unite Kingom, 2011), the Orer Bge К.К. Rokossovsky (Russin Feertion, 2011), the mel Gret Mins of the 21st Century (USA, 2011), the mel 2000 Outstning Intelletuls of the 21st Century (Unite Kingom, 2010), the ertifite Deree of Merit (Unite Kingom, 2010), the Certifite of Honors of the Cinet of Ministers of Ukrine (2005), the Bge of Honors For Sientifi Ahievements (Ukrine, 2005). 118