Document rp49D8v5NVxz2a6EX8yZpMVaE

1A. LEAD INDUSTRIES ASSOCIATION. INC. o 2*1 MADISON AVINUI NEW YORK, N. Y. >0017 February 20, 1964 SUBJECTi REPRBT CO LEAT Ei^EXS To Heaters of the Lead Industries Association, Inct V/ hare obtained copies of the attached reprint on lowtemperature, lead-bearing enaaels for steel for distribution to enamelers, frit manufacturers, graduate ami under-graduate students In enameling, and others for whaa this study Bight prove useful. This work was done st the University of Illinois under a research fellowship sponsored by the International Lead Zinc Research Organization. Particularly where students in enamel classes are concerned, we think this piece will servo to encourage further work with lead. In addition, this reprint will be offered in the "Lead Library" listing in LEAD magazine, which is sent to about 3,000 ceramists. Members may obtain 25 copies of this reprint free of charge, and larger quantities at our cost of 11 cents per copy. Very truly yours. dmi Biclosure Q oo* 'f LIA23996 Q {K*linUJ It- mi I Ik 4n k v Sh m IMkoi, V<a 4J. Nu 11 Si>nU< 7 I'*i | Molybdenum trioyidf (MoO) in 'omb'nrtion with lerd podo<et le*J molyb date cryxfdt winch m<iy $ffv< j j jn opwolief in low temperature enamels. C/yi* taffmticm chaucfemtict of (r d mofybdite, with rexpcct to composition of the enamel and firing temperature, were ;tuJ>cd. The influence of u/e and number of cryttab determined the reflectance characterise* in th< '**W< vpectrym of the enamel. Methods u*ed in thij investigation were X*My analyst, differential thermal analyst, and electron microscopy. Crystallization Characteristics of Lead Molybdate in Low-Temperature Enamels ft. ft. AMIN iMftl> tlfcWftHqf, |fftftrtWf PpftrtN|l< 11 ** *+* 4ft |Cft,K W.Uii<|0\ 0*4. t. U COOK Uwft*n*r *4 lMh, Ut Wm, BL C*j o w-1KS4r:fc-Ut'1cfc C.viMFts hiving o|>aoty cvmistrabk to cnnvmti>ful wlu'.r main* Is and fi/inc tmijsfjturr ; V * a* l.'ui'F are difficult to formulate. (kncraHy, kad-b-ro `ilicttf tv|w *4 gU.vs U used fi*r the kw teni|rrature rtutnrl If a crystalline imtrnal with a high ink z of rv{raiti"ti h t*> > uvJ as an {4nlwr. it diould tc Muh Out it ran Ir ratify crxMalli/rd into a Urge numUt of Miiall crxstaU in thr trad ( ao-alii-atr tnamrl Jas matrix. Ihc weakened structure <4 lead glaw Vvnn to fa\xf tIftC iT\'t^lli/ath-n *4 Urge i<>nicc mj.V w'1 like "*,\Vt V *. Cr< V*. und l'i Lead roolvlntatc, ItiMo* VitatTVfttallifir coraf/uml luxing a tctragimal sclKvhte Mnirture like Cu\Vt ** and a huh indrt *4 refraction <4 .`MW-2 HCj. The melting |n*int *4 lt>Mo<, ts P.H't'F, whkh it huh enough to give a stabk crxstalhne l<rcipiutc during die firing jrv-w of the enamrt Ihe jnr|>*nc of this invrMigatkn to Mudv the cryMaUi/alf^t characteristic* of kad rrv.hUUte in Vm-trin|*-ratnre enamels ta'cd on kad-Nif.^ilk-ate glasses and its rrfWtatKe char* :*trrittic* in the visiblr Kfcctnim. There H very tittle* information availabk in literature aUsit the use <4 Wad m4x Mate ct an uparihrf in kor trmjrrature cnartirb; however, KauU* has dcvTilcd ko lrnij<cfature Prrftcoird at tlie Sixty Fourth Annual Miytinf 4 The Amert- ran CrtamK Scirty in New Y*k, N V . May j, JUrtJ (Crtamic* MrtaJ System* (hxi>ton, Nu 14-H4S3). 1 W A Wrxt. C<<lurr<1 tiUftw** p HI. S<Hy 4 <Uxa OTo!in>l<"fy, StKlfiiUI, lU5l Ml 4*| , <Vrw ,|x*i , 19SJ, Sj-nnitirf. p I.Vhf; reprinietl l> 1>4n 'i I'i II Mall, fa-nilon, Ml pp * Karl Kaufr. M'-lxlnlmum in FiuinrU: 111, Tij -mI M<>lx lalruutn FiiatiK'lft,'* J. Am. Crf" A** , 4S j.'l| *<i Hj (IU4A). Voc. 42, No 11 (19113) nuoifb in wtmh lau*r aiiMiots <4 kad naJvUlate in the mid lutvli (re*-luo(*1 a ite:nj-whitc "j^.juc enamel wjih <! ad* bettmn at a 'infig tcmprmt*jrri4 about V-HJ F. A vtfKx ( frit aitc forumlalvti to the cffrrtx <4 \an<>u> frit o*o^titiKtjti the i r\'tatti/alk*n char* acteriNta^ <4 had rraJyUlatr in V>w-tmfTaturc rnameU. iVrxrnt 'xik o*m|Nr*it>*n *4 the frits arr gixen in Table 1. Hen# frtelmtflf of l/w Frit* o*4 X*toy Aanfyvo lirat tn atUM-nl if the fnt> Masrairtrdout in a tula* furnace. Fifteen gram* o( dry ground frit (l',` <n .tJ-mrh 'kxt) waa heat trratrl he I '* mtnuto at xarkais tempemtun-x Iwtwcen |0t>i* and i:it F. The hial treated frits ws-re ijiuntitalixelv anal) ml b> X-ray dilTractioa a iu Ix ms using an internal stanilard trchn*{ue. fitomof food fttporotiw Tlte dry ground fri*n nree alv* uwd for the slip j^ejiaration. The miU lifttrh u>cd is us ft Jhws: Oound frit Colh*i<tal silica Water UW <W 1.7.1 `W Ckuncd mana t graile iron panels with nickel ik|i.itin of 0 HI to 0 1*4 g firf Kfuare foot nertr |Co`sidiml at WUU'H fc 5 mimitis l lw |atv!'' were x|<axcd dircctlv at a weight <4 application *4 Jl g jwt pure foot and wr fimt for 15 minutes at vaibiis lcui|<efaturrs Irlwren tOW and I3**1*R The rvflectame i haras tcrbtic in tl. vixdJt .j^itrum <4 the IsitirU nusoMuii'cdon ft recording sjrxtfo|*l>ciU-nietie. 7ri3 i N 1971.01 LIA23997 \u so, I't^i Ni,(l !.M> H/S /nO M'A N*SK, <1* 27 t XS ttA 17 .V In 41 3 11 A It H 41 Table L Compoufiom of fnomels No, 1 to No. 12 ha* hi ~7: tel :.s n.i 1A "A K> 47 \t> ;n ftt 14 AA >41 4V 47 .<4 .-si H 4:1 WnS( -- \tu4ta piwialoths Nivsr^anai .5/ >4i 4U 1A :ii m 1J (M 4M '>4 .11 IV 14 M 47 nx ;a a 14 44 47 40 ;to i>4 14 so in M .U 4A 1.1 71 4V xA .32 74 1.3 40 2J IU ;u h i u io 14 71 A 11 AU H 41 10 21 A 11 A II N 41 I*i Tfl a at x x; ;ci nA a is 1 16 X 77 10 U A 41 .1 M h no 10 II a <t n n At lO 01 am 7 u S 44 11 IA a AM A 2* 10 W) A 45 a 45 2 23 lo nn a. na a ;a 1 J9 i mo mImU(.us 47 Urt ao na 10 oA 2 .'*( 10 31 Ml a ii X 41 0 Result* and Olicutslpn tffmci o/ f4ajO~PtO-9fO$ Frit* No. 2 am] No 3 acre >|<a<jue and showed iU the in* tense jeaki of trad tnofyULte o q the X*rar diffract**a jat* trfn. Frit N'*. I shewed only roe, (hr trvnt intense j*k uf lead molybdate; the other jrak* wrrr n><t well iWfined Nocr o| these frit % shewed any crystals at the smrUiny tem|>criturv d 1x* K. tl that a cs-asiderable amount of Wad tt*4bUle h>*4ved in the (rit at the smelting tctn|<Tlure, tail the frit Iwwrars a supersaturated solution lilh fr^|rrt to Wad nn-l\!Utr as it it evaded Figure l shows the j fc.U <l farsvut Wad nwOsMate crystal lized versus the t*tnj*ra(ure .4 heat treatment fr frits No. I, \< 2, and N<> 3 Tln^f result* show that an increase in N`a<ti omtenl al*>er IAiW'J at the r\j*-n-< of either |1/ or 11/ h rwilted in an imfrasr in the *hillil> of Wad n4\ Ixtatc in the finny ranye <4 the enamel. Frit No. 1 may have mati- n.umcrs stalooitent at a trmj<ntufe V.aef than lOUn'F. After tle heat treatment a* l<'* F, frits N<>. 2 tad No 3 showed a hlutsh odeat; ~ afuk fnt Nm t did tv*. The hluidi o.Vrfjt.a> a th u., u I* due h the tust sta*e *4 crystal irroath m wh*tb the ,Tstah are very smaD and there is an effect of Wa\Wi<h ^ttefint The IJimh rd<eti>m turned m*<e while as the trmjeratufe <*f heat treatment was iocreavd. to r*c*Wr to yet KHd clmsy riUDict, the linni tcm|M-r!ure *4 enamel No. 2 was about 114A*P, and that of enamel No. I and N*> 3 was ll.V)*P. The i|ieeiri|h<>ti*roetcf curve* nf these enamels are given in Fig. 2. Here, ah'', the increased solu bility <4 Wad molybdate cryruh in the tiring ranye of the enamel No. I is noticeable. Htd W MmOj Concinfrofion Com^sritko No. 3 was srWcted as a base fur this sfidy. To the bu*c c>nt|e>stta<n los the nxdybrWnum irsoude (Com* poMtiuo No 4). nchbtions of 00. U*k 3.13. Ml. 006, and 7 U/i d tn.4> UWoum tfiuiidr wre made (C*ni(^utMo No. 4 U No HI. The frit with no 4ldit>n<d M<4h ai cW-ar and did not show auy (vaks on the X-ray dtffractkn flatten. The frit nlh 1 t*` c addition of M>Oa was shyhtly opaque but did show anv f*ak* on X rav diffraction fxtturn. Fiila with 3 13, Ml. t. t*i, and 7 t*K'J additi<<fis>f Moth showed the je-ak* of Wsd moivUlate Figure 3 shows the roW uf Mi<W a*ocenlral*ra uQ the amount d Wad rrwdvUUte cryrtalUred after best treatment. Thre is an inerrase in the amount of fcatl nv4\txiate m-stalhrrd with eaih incn-romt \4 uvdybdrnura tno\*W Ihrsc results <4 X-fav analysis sb>>w<-<l c-d o-rreUtK-n with the {trf*fhdmeter curve* (Fiy 4). There was a marked increase in rtfWctance with an to* > Meet 7<H N,f) hO I|0| **i*^i ** Ha erHsAitii** f Inf oirMsn (*pnAs l. 2, toH x T*. 2. ml N*iO fbO-ltOi vw>Kw mm W nhrttwt ml rnwl !,2,a4X CfsKAMtC Bl'LLKTIN  *** >. O LIA23998 uiS. 1 fif 1 f#*c W Oi n A iff**t t+*vr W V4 MoJrh~ **o%4* ( 3 >3% M#Ow (31 3 11% MwO,, *4 lt 7 00% f-#. 4. P*d *r auOi usiweo w > rtS<Hwi mt aa^osainw 14} 0 0% MvOv <31 < 04% *WOfc til 3 13% <31 It t% M*Oa (7) a 04% MOi, --4 (SI 7.00% MaO crease in naJyUlmum trvxi<V- content. A crtm^fMlinn with t*! tifc4) txVnum tr><xfc addition had a rrriectaace value f slightly Irvi than F'J I'rolmMy m-rsl of this reflectance it due ti the |tr**nct l*iU4c*in the enamel structure. X ny diftractt-.n < f this frit, heat treated t.t viriv* tern- fe-ralum brtwien Hn* and 12U'F, W n<* show [wcxnct of mv crsntallioe material /7#ef of NjCF* Frit No 3 contained t4lr,' \x*FF; in this l*arf compnseti-n less the Nj >i F (C'-mp-'it^ej \< **, *ddilsns 4 00. 2 *A, and 4 ', *4 XajNF* were nude (CompMt*4is No 9 tu It/ Frits with 2 J-l and 3`**T- ad'htiou 4 Na*SF# wrrr (<(<a<t>K white and showed foks iff lead m>,KS>LitcTbe frit with no addition of N*aSF* u char and ibd tvd show any |caks Figure 5 shown that, with increasing amounts of XatSF*. the maximum amount of lead molvtuLte crystallited bv heat treatment has hrett shifted to a higher ti-mjetJture and, iUi. the anwamt of trad nudyhitate was in* ertavd \\ ith no addition 4 XaSF. the maximum artvsint of lead m*dv ?late crvstaEi/rd in the frit was not n**T than 2 to Figure ti 0k >w that the lelVctaW* value wac in creased with imtea-e in Na*>iP aildilioA, and there was lesw e/Teil of Xsvirijib Muttering It 9|<}<an tlut the ioctrase in No*SF ad<titioi not only increased the anwaint i4 bad mofytutate crystalh/rd hut aNi increased the sine (4 the lend molybdate crystals Hh<t <* UgO Sv MmIm In haw competition N'n 3. 2 -VJr 1.1/* was sulwtitutrd fot Na/ > tCompiMti<*n No I J>. The elfsxt of U/) o the cry** taltirat**} of lead mi4ybdate is shown in Fi|. 7. The maxi* mum (or the <4 lead moiyleUlc ciystaflitrd was shifted from IMl'to l(kkjP arul, abn, the sohiUlity of Irad nv'hlwUte was increased The jecUii|*hotometcf curve* (Fig K) show that llc filing tem|rr*tur* and the nflcvUtwe value werr reduced with Li|0 substitution. Enamel No. 12, when nvtrfitrd at lluiFP, gave a very low fcrtcctapee value uf about l^J. There wvre three factors crntriUiting to (his ilectra.se in rerteidance: (1) the lead molylxUte crystals were Vo l . 42, So. 11 (UKV1) hf l tr*d *t ti, a cmNlistiw f kef MfrWt la u*w4w (tot ni% OH 4.]% NS.r aad (3) 1.41% NrW di*w4vrd at the higher firing liiup raturr; (2) the lithia sub* sitution m-uie the enamel glavs im*ee fluid, and the buWdes were frm-\ed (tom tlw eiuiiwl matrix during the firing jemt-vi; and tlie lithia omtaining enamel glass was very rtattisv and di*v>Ued a(>{)frciaMe amounts >4 iron oxide formed during tlie |*roxilat*m of the cleaned foetal 705 fiauew iM iin iii. w ii Ii III Ii.* - .,n l , i l l i l i i i LIA23999 WWJWMIB 1 4. (*k * W N*fV) r ** i Wpw<wi (10) 1.})% H*M* (III 4 3?% M*.WV *4 (3) 1.41% Differential Thirmd Aoofytta Varai frits *b*.rd vixujl m*,ij of crystal pTowth *>y change in o-W-dk-n ft- m Hui-h white to white at the *cni|Tature of heat trraimnl wa* UHfrawd ffnlJi 1UW* !** U*iOaF. Frit* No 3 and N- 12 wire M-Wvted f*< this invrstirfatk-n. A manu-illy <*>ntr'Ild f >TA aj-jvjratus was used. Tlie tbrfn<kf.*mt < frits No. 3 and No 12 air to Fig. `J An cu.^.ihcrm due 1< the water removal *a of .served at Jin' to 27-VF f*a tMh the fril%. In frit No. 12 sut*titutio<i 2"f,' |.ivp* N\< j > *)iri} a fJnti j'f in tniijefj Ih t c f>( crystal icr-*th cv-tlntm from 117**'' to lor^F. A <lcvrease ia tcrn,>-r*i:irc fr-ni ll.3 to was also o!#srvrtJ fw matitmtm crystal o-t nt n Iwat trwtnietit t*f tlie frit Eltdrott Microscopy A 4r iniesti^ats-n <4 hat Irraled thin Jilms id enamel i|tit No. .j! did not proxvle enough inh-cttutkin ih<it the il h.Ut a'wl ilw- map ( lbe lead mnhblilr it \slats. This was due to the small sire. i*ru!iul4y brt.w 0 J.V, id the lead mr.Mfatc crystal* lhi* fact wa( also (>f X (H< UrO m #s# 4wlwn M wti4w ()| 11JS% N*Q, 0.0% 1*0. U 0 3) 10.05% HmA 2.5% MX evxknl from the |`ctfofkt<nKtcr uf the enamel janrls. Tliev showed higher reflectance value in the slvwter wavelength regkm of the viable spectrum because of the small sire tJ the cry stall. TlAnvl No. 3 was selected foe electfto microscope Study. Fancl* with an apffM'atk*n of 25 j? }<rf w/uire fi* ami tired at II.Vr'F for 15 minutes were uvd he the rej-lH-aikm. A clr^nrt) j mih -1 no* etcJwd fur 2 minute* by 5V < glacial acetic Alt acid solution in water. An intermediate irpln a of the etched e#F irfa<t w.n icrpaml using Fj x Film plastic Uj*. Carbon replica was |c-j ured fr-m the iuUttmdijte replica. Carbon ftplu-a w j s examined in an HCA-liMF model electron micro* to-je An electron micrograph (Fig 10) shows one denar and a few sparse arras id lead molylidate crystals. This study showed that m<r.t of the k-ad itK-iyb-Ute crystals prevent in the cnattu l r Io s matrix were nuulti. Sh u t intfuU/ly sha|d crystals u<-rr al^t |>ft-a ut. 'Hie longitudinal dimension of the crotals fanned from <> ^to 0 2#. The other irregularly sha|<-d crystals were all below 0 !.'># in sire. These results explain the Ka- ki^b vjtUfing oliservctf ia the sprrttnphtv tomeler cursx of enamel No. 3. The c*>l#f of the lead niolyb* date crystals in macro si/e is jsile yxllow. twrt. due to the small arc of the crystals txbw 0 2^ the enamel appears lihii.0i 704 T l>r<X n :- r^. 9. tWn^fiaM 4 h.U I)) 11.55% N&, 0.0% ll^ ** (11) 10.05% N*iC, 15% UA Ce r a mic HbLLmx LIA2A000 1 white. The cream-white col*** ofnrrvcd by Kautx* vu jeotatily due In the larger sire <4 the lead molybdate crystals. Summery 1. Lead molylxUte crystalliied in a Ww-temperature enamel gta.*4 mains into a large nurnher of small crystals and im|iartcd *. the ctumrl ft rdkdanct value of 73 In Nl*c The ojacity olttainrd is e<tnj*aru4c to the white enameb in which conventional o[>aa6cr, such u titania. rircooia, and antimony o&ide, are used. 2. The oU-cfvatiuo <4 melt onviili-n and the results of X-ray tlttfractiiai analysis indicated that many of the frits were MprfwtwatH with lead im4ybdale. 3 i lie v;ri**u enamel constituents have marked influence n die cn *ulti/aiioao( Wad molybdate, y A 'MMtimu oxide content of tth** that in these rnanu-li incrraM-d the Nolulalily td Wad uvlvlxlale to a O'MMtVralde citcnl and adversely affected the ojtacitv. b. An inert.*** in mtdylidrnutn trioxidc content from 1.00 to 7 i increased the amount t4 lead m<4yl*Jate iTvUaUi/cd and tile reflectance value. t. S-Jium mIh s iIIu i ride addition* up to K 4lJ increased thr t ui|rrature <>f maximum amount of Wad m>4ybdale it>sUlli/cd by heal treatment and, also, the amount Out wascrystultixed. 4. Sil^titution of 1lithu fw **ta lowered the tcra- jaralure of nuvitmun crystal eftfent by K39P, ia* creased the *4uUUty of lead molybdate, and lowered the hria* tcmjwrature of the enamel, 4. Ihffcfcntul thermal analysis of two frits (No. 3 and No. Ill) showed the crystal growth exotherma The tempera* lure 4 ibe exotherm* were clove to the temjwrature at which maiimum amount of Wad nv4vbdatc crystal content was ob served on heal treatment of the frits. 3. tCVclroft raicriMcofje study of tiic Wad molybdate crys tal* jnvtit in enamel No 3 ibiwtd that roM <f tlie crystal* were acicnlar and * >me were irregularly shaped. The -ire of the crv*uN ranged from 003 to O 2a. * he small cine of the crystals gave anciplaoataia he the Rayleigh scattering. it Ack*oW4t** Tlte writers are grateful to the Intemstvasal Lead Zme Re* iranh (>r(4nibli<a A*eulfsl fttlh tie La-ad Industries Awri* at he the financial iNstiiMi which made tlm writ ptutiMc. l)wtril>utd by: LEAD INDUSTRIES ASSOCIATION, INC ,* Madi**t Avenue Near Vurk, New Yurt 1<mi7 VK.. -12, No. II (1UG3) U>WWJWIOW <' 707 LIA24001 mm'mtkrTl