John, S.

Perumal, A.

Shenoi, B.A.

IR@CECRI

GOVERNMBNT OF INDIA. THE PATENf OFFICE.214. ACHARY A JAGADISH BOSE ROADCALCUITA-700017.Complete Specification No. 150164 dated 31st Ootober, 1979.Applica.ion and ProvisioDal Specification No. 121/081/18 dated 5th Ootober' 1978.Acceptance of the complete specification advertised on 7th AUPlt, 1982.Indel a t acceptance - I 70 - a , ~4 +"1JInternational Cluaiftcation -. C a3 f - 5/00• '" IMPROVBD PROCESS POR CHEMICAL COLOURIIOOP AUJMINIUM AID ITSALLOYS SUBSTRAft8 IICOUBCIL0' 8CIIBnrIC AID rXOOS'!'RI.lL RlSEARCR,_atl "ar., lev Delhl • 110001, IudS., an IDdlauRe&I.tere4 bod, incorporated UDder the R"l.tratloaof 80e' ,ti,. Act (Act XXI of 1880 )Tbc followlollpc:clJkadoo delcribe. the nature of thit inyentlon.150 1 6 4This 1. an 1flventioft ~y Uelkunje Anantha Sheno!,Scientist, Subblah John, ~nior Technical Assistant andAngusamy Perumal, &en1CJr Lahoratory Assistant, all areIndian Nationals and employed in the Central ElectrochemicalResearch Institute, Karaikudi-623006, Tamil Nadu, India.This invention relates to improvements 1n or relatingto Chemical colourlng of aluminiumfn and its alloys.Hitherto it has been proposed to .chemically colouraluminium and its alloys to various shades in the followingways IThe modified Bauer Vogel Process produces light todark grey coatings depending on alloys,The chromatin~ pfCeS8 produces colours ranging fromiridescent yellow to brown coatings from chromate -fluoride baths.(JJ The chromate - phosphate process proc1uc&s lightbluish green with slight iridenscence on copper freealloys, and an olive green colour on copper containingalloy8.(4' Black colours can be obtained by immersing the metal1n a solution containing potassium permanganate,copper nitrate and nitric acid at temperatures of80 - 100°C for 20-30 minutes.(5) A blue bronzing solution contains 5g/1 each ofpotassium ferricyanide and ferrous chloride.(6) A grey iron like colour is obtained by treatementwith a solution containing 25 g/l potassium sulphideand 1 911 vanadium sulphate at 800_90oC.(7J A reddish brown colour is obtained from a solutioncontainln9 potassium permangana~e, cadmium nitrate,ferrous chloride and--2...-en,\. nt. t 't'i.~ "a.ci.d•.'i2'l(i mldn draw backs associated wi th 'the hi therto lmown2 ...SC!('4-procesn ar~ thats-1) Wf; MBVin".::;cess j)1'Oduces t r1d~scet1t sha,des and they are not.~ att:';'~d~l.fIe as t'<:i meat the at'~hl itrctural applications. Moreovertn., coating is very thin or f',be ord.4u" ot 1 ... 2 micron ••2) tha ~h:roI!18.Hr:gprocess produces iridescent yellow colours offilm t.'1i ~~iffiI3SS (I.1-Vu and they ara not all attractive as to standthem3elv~s fo~ archtt~ctural applications.3) the ch%"01l2ate-I=hoslilate process produces attractive greenshades of t.hickness ranging from 1-5 lu But the rang of colours18 restricted to green only.4) Bath numbers 4 & 5 produces non-adherent smutty black coatil'l&aru1 are rlo!"·_·uni torm.5) Baths given 1n 6lt:1 produces very thin coatings of tile orderof 0.5' tc .1/1J and are usually iridescent Q."'ldnon-uniform.'flu, Illdn object of the prf>sent invention 18 to obviate these41"al!TaTltllges b'y u31ng a more versatile process for producingYQr1nn. ooloW's sui table fo r arch1 terctural s.ppl1caUons on alum!- ,'ftle main finding underlying the Invention consists in cheMic-'l11y b:'&atL1g aluminltlD and Its alloYs 1n a.n a.qUf'O\lS solutionco.pr1sing knmonium carbonate, 10-50 g/t carbonates nf Zinc, Cadml...\IE, Manga11as~ t L~ad, Nickel, Copper and. Iron aingly or In combina.-tion 0.05-0.1 g/l f Ethanol 81IIjne9 having carr)('ln atoms 1-6 1n amoU'ltIor G.5-5 llII!l, sodium hydroxide 0.01-0.1 &/1. F,t a pi of 7-10 at atemperaturft or 80 -1COoC for !l period (,f 3-2.: lI'llrlut.es whereincoating thlcknesp. of the order of 3to7 n-11(::rons can be produced.'n1e l'H?~' resul t no."ing from the nev fJnd.1.lIg 15 that varlot16.ttrMtive shades ranging from grey to blaCk. ~id yellow tc bronzeaold bro ....n ~hades 911table (or decrative and architectural appI1cat-~_cr:~ ,,'11 r~1.~lmtnium and its alloys can tie produced.'the n<:nvol feature of th~ present invention :is th:tt variousahnrte3 (,n aJ.'..tnin1Ul1l aJ\d 1ts alloYs can ,be prouuced in short dura-tiona ft'"'!lJl t~~ b$J.th~ ccnta.tn1ng che..ply available In&I"edients.'!:,. .1 50/lt+·•• no ...... .. • -~., ot the ~ae •• 1·... t.l1oh.*Ibllltlm •• 4 Blltftnl. J ........... 1a 'Mab1e__ tb71.e....,J ..........uJ ·'tfub 1ft .!. ....~ ... 1D .... ....u.........J . .INat 1ft .. ~ .. 1utt... 1ft ~, .. ' ..... .., or rta-._ ,.. ~ ..,. .... , .... U.. II Ifta""- .. ,.I..., .-1-.r •• _ta111dn1 treated ... eelOUrN filii. _ ~ ."..-tuoe tile __ rt~. oon41tlOft of ..... ...,. W. --,_ Mo... a .fte,." etrects ren1t .,... taM _ •• 1eurta•. tna"'·•• , •• ,.clinl on Whether the _tal ha" .. p..., .... t.. _ acid..... , •• ' b1.. t~1 .cratob bneb1 ••••••... fe118,da. V_oal •••••• .. • ..- to m.... te.. . '"bov ...... _t .... ts.on 1s e~tMl 0"\ ill _\11&1 ~ .... bat. ... .not to IJ111t tbe I.pe or tht •. 1IlWfttt_."&'LIX.:(tdntlMl 99~ At) l1-.tRl- •• -. .. p...., ..... . .tl'l.lo~ •• t· .toIled 1ft .. r.\ka11De .1"''''US-tU 5'0-" 80M.. b)'clJlDd4., ~nM4 ..... a.lI_ sa 1G4'_,a-o .aUv~ .... tilI_ __ ... 111 •• to1lo.... ....... _1oarlll,.i_t.()ll•....,. •• C~ .•te.........1....... ~.teI..i.llf- 0." fAa.o ~ o~5__.~,~~i~-=!t~I 5'.'-+rc IS.. !tvfltln1'M1ft7 u.auJ8 l1\1111l1_ (oanta'JD 1.2" JIll, hft·A1) .....a.•• re""uH 1Iltb ........ 'all'' 1D i4 1e111\101l ..... 1Ir4ft)n_",o .i4 , •• '1'1•• lj 1' _. ~ned·1D tIl.,.l1oVlftI .. tlb•.......1_ oarboa."trl l ·,·M teIII!WP.l' 1110.' 81/10.' 1/1'l.J .t 0.5'",~'ek gE". ft.3 Mtn'0 111ft.···AM26 • al.-1Dl- <"'.25:' Cu, ... , Al) I&&t•• we... clelft~..tvi. 'l'SeII1ol'04ttih1'1~ •••• Mb. 1ft • 801ut1oft oenta&n1D1.. 1'1"10 ehlor14. '00 cI1. "'ft)ohlol"1o .. lel 1So 111/1"atile4 _4t-..... 1ft the tollovlftl .1utlOil..... 1\11 oaJtoDateMe tbatollIdfteJ)1Il2 111/10.1 1119.0 ~.o.S.to .t 200Jrprp- pee ...Liabt ,..11ov ....,1\8 78110"'Dal" "110".... II26 I .Q.l_tnlUID alWa "ere cleere"" with· tl"lot'llollOethy-1... "ke .... ,. a1~ lDlaU. ..... ,-'10111 ... -...4sISo I "4020 1/1 t.I1.80d1\8 rtto81bate a.t So e tor 2 te 3 .tn. '!I'd oMa1edl1.11 •• (1. to prodllCe a nearl.y mirror br1lht ,ttlSlah "allb" •• 'rea-tea ill the fol1Ovlnl solution ..-.on1.oarbonateJIeaoet:b.aol-me.1okel eanaaat8pM'10 III1 rJ1/1o.S g/l8.0.t o.s9S .:t 2°0_,"1 go 'Dee Mev3 1111n\0 lI!nLilbt yellow001.. yell.owV'd.ILHtndallU1ft plate. (contd.n1n1 ....0 - ....~ Mg, 0.5 - 1.0. It0.1. eoP1Jl8I').en 4e11"N.8ed, etCb- in 1_ IDa. b7datd. _lu","laD ... fled etched 1n a _lutlon ~tatn1DC ~ 1/1 "Pdo ale"'.11S .1/1 hydl'Oobloric acid "asbN tIlel 1"1"'" ln the ~1ID, ••eolutton.~1. oarbonate.ethll'lOl U11ne'or.1'J'e r oarbonatepHreap. -SOa/11 a1/10..2 ~9 '* 0.1as '* aOeS_Ul10 ..inp.",llll8\lt»"r pl1"l:tY a1\111n1U11l ~18 "ere 4eSfta.eel alW·•. tab- 11'l 2_ 8041- hYdn>nel. _lat1Oft, Vdhe4 ~1IPe 1Oi--.1\1'1c: ac14."eel e1eotrope11ah- _4 1- ..... 18 u.-a-bath.• j ••20!/11 111/10.2 I/l8.0.t 0.1 .9l$ .s aOotIIIIoD1U111carbonateftot.ethllle1 .-tn.c.-s,- ca.r'*'a.•3 II1R 14"''' 1hJ'10 111ft Dark b__ 1* .....IMIN III'ac..erela1 parity &1-.1_ &1107.wen _.re..... " ...... tD WIIII ~nl_ b1 n_rtcle, 1S.Wttrtc "ld, vaabecl •• s..-r'" 1ft theto11oV1111bath.-..on1_ caJ'bon.t. lto&l1M.tbmo1 lIJdAe 2 111/1Wloke1 oarbon._ 0.01 IIICopper carboftate 0.1 V1_.,R .01 &/l.'O.SIII 9.:t'hap. fJ1 .:t 2°0JEPM. V- pelON, tdft Li.t b1aek10 IdD lIecIt. black-ru j.t blaok..... !lUa. al.s.at. aU.,.. wn ... re_ .... pi"M...... .., Jlr -.. ....YIt .......n4 1.erse4 1ft the tol1o~ftl bath.t ...,nt_ oarllDllat.e 5'0 all.......... 1ala. 2 111/1'enoD oarbollata 0.1 1/1Cepper .....-n.ta o.1 a/11.08· O.t &119.S.:t O.S°9O..t2CII 7",01 M. fliRleMlU.abt browai.tl ."'MtMU.1II b~l_ IIWDark brwnll1l ant'.J.t ~.- •to •1, •...,- ...61S ~.1 __ (1.0J& rntI, 0.6" &i, .0.2SK Cu, 0.25 Cr~.t. Aluminium) alloy_ were d84jJr ... ed 'and pretreat.ed a. in lxampleYJI and 1... rae4 In the following "beth.__ onium CadlloR4lt.D1_benol-.tn.tine c.rLona~e21 vii1.-1/1. 0.1 g/10.1 Q/l.01 Q/lCapp'" carbonateNaOHpHor ....1285'499 !;aMS min·.8.5 .t 0.597 .t 2~~WQht. 9re~1.h y-.a.~MecUum gr..,iah yell_, Dark green1ah yellow.10 m1n,20 II1n. 'The _1r:1 ad¥.ft~.98a of .. p.-'•• ,invention arel1. Thechemic.l. involved in thi8 proe ... 'are dh_p and h.-ce2. ~ wide range of .hade. are obtained on aluminium and ita.1101'11.Da-t.ecl thla 30Sib} SOi6.q.THI 'ATINTS ACT.I'"COMPLBTID BPBCDr:lCATIOK( Section-tO)It AJJ IMPROVED PROCESS P'OR CHIOU CAt COLOURIlIGor ALtTMIlIUM AID ITS ALLOYS SUBSTRA'l'B8 ItCOOlfCIL 0' 8CIRml'IC un IIfDUS'l'RIA.L RESBARCH,Batt Marl, IfevDelhi - 110001. India, an Indianreli.tered body inoorporated ~der the Registrationof Soaietie. (£ot XXI ot 1860)The !,tllowiaa apeciftcatk'D panicularly dOlCribel and ucenain. the DatU" or thiI iaventior.and the maDDer Us which it II10 be performed :-'115016 4Th1.s i8 an J.,nY~n-tion by'8MJ<UNJS ANt\NrHA ~O1.,S~i~1Et, 5UBBLhHJOHN, ~enioc &cientific ~s~atant andANGU~~ PSaU*L, Junior Technical A.ss1stant, all areIndian Nationals~nd employed in the Central &lectroch_llcal,aesearct, Institute, Karaikudi - 623006, Tamil Nadu •. Thj,s invention relates to an improved ~rocess forch81l1caJ. colouring of aluminium- and its alloys sUbstrate ••Hi t;herto , a number of process have been propoae4 t.ocnemical~y colour aluminium and 1ts alloys sub.trac •• totvariua 8hade..~hee.are mainly:-I-1) 'The modified Bauer Vogel process proclUce lightto dark grey coatings depending on .lloya.2 ~ The chromating pcocess produces colours raD91nvfrom iridescent yellow to brown coatings f~ Gtu:... t..fl\1or1de bathe.3) nt! chro_te - phosphate process pmducu lightbluish green with 'light irrideacence on cqtper fneallo,. and an o'1...1vegre~n colour on copper CODt.a1ningalloy ••• ) Black colours can be obtained by immersing t.he ... 1in a .olution containing potassium perman9&Da~., copper'nitrate and nitric acid at te~.r.tum. of eo-ldOOCfOJ::" 2(). 30 minutes.5) A blue bronzing solution contains 5Q/l eacb .fpot.••• 1um ferr1cyanide and ferrous chloride.6) A ''Jrey iron 11ke colour 1,. obtained by trea..-at.'. i ' .-1011&""w1-.c;.b • solution containing 25 ;/1 potas.,., '\ 0and 1 g/1 vanadium eulpbat.. 6t 80-90 C.-~-1'501647)' A. redd'Sh bdWb c»lour is obtained fbom a solutioncon.::ain1n~ potassium per\1la~a", cadmium' i"" .~_ n ~rate, ferrdusc:hloride and nitric actd.The main drawbacks associated with the hitherto lu1~pro4,:.S!! are that Jthe modified Bauer Vogel process produces iridescentshades and they are not so attractive as to meet thearchitectural applications. Moreover .-t.Lcoating is verythin of the order of 1-2 microns.2) the chromatir19 process produces iridescent yellowcolours of film thltckness 0.1 - 1 i -m cron ,and they ara not.all attractive a. to stand themselves for architecturalapp.Lications.J) the chromate-phosphate; rocess produces att.ractive oreensha,i •• of thickness ranginy from 1-5 m1crona. But theran,;,. of coloUr. is re.tricted to oreen only •.. ) 80th nwilbers .. and S produce. non adherent 8'rnUt..tybla,ck coatlnq and are non uniform.sJ "th. given in , and 7 produces vary thin c,...t1D98of the o~er of o. ~ tQ 1 micron and are usually idcleecentand non unifo~.The main object of the pr.sent invention is to obViate~he.. dis-advantage. by uaing an imp~ved proces. foeproducing desired colours sUitable for ardhit.~uralapplications OD aluminium and ita alloys.The mein Un41ng underlying the invention consists ,1n.the us. of an lmp~ved aqueous solution C:OIIPrisiDQallu"""1~mand its allays.The .-in finding und~rlying the invention coosistsiD the ue of an improved. '1aqueous solution comprising aU a.I-,;:;~:carbOnate 10-50 c;Vl. carbonates of zinC cadmium, rna~·.lead. nickel. copper and irOll 8itl91y or 1n cOlRbinad:OIl0.05-carbOnO. 1 91'1: ethanol a-mine havinQlatClm5 1-6 in all'ldanteof 0.5-5 alIl, sodium hydroxide 0.01 to 0.1 g/1 ata fH ef7-10 for 1_rdon of the meul'at a temperat.ure'·of ,eo-l~r-.()r • ~ of 3-30 "min.to...... ce!n coat.,t"DfI ettt~ •• " ..- 11 -1 I 0 1 , •...... .. J .. " ..... _n° be IYOClIIc:e4.'~ .-in "'~JKqe. of t.h • ...-ent. lnvent.10D _•••-r ch"oa~ iDVo~Yed. in "tb1. proc_ an .Clheep... b meN ~_c:al and a ",1ele ranve of .... ar.tl*aln_ Q11 alu.1ft1wa and ita alloys.fte lnvent.tqn aceorcUllCJly pew14 .. aD 1apEOVe4I'I'Oe8S. '~or eII_teel colwr1ng ol al~n"URI Met ita al~.-.trau. c:alPC'181n. t.h. .tepa 0' pollshlD4J end , ......"'1'_,-,,, Uka~" _cltlD9, acid- tiPPlA9 aDd i ..!_.• Ch-.taaJ. betltwh*re!ft the .t"hV •• t~.iet.. ia.-t an acau--.a aolR1on containing lo-~ ell of _DIli ..eacbo~.. o.05 ~ 0.1 9/1 of carbonat-eaof sine, cadai-._ •• ~. 1_d.niok81, copper an4 iron -l191y or in __ 1-.. 1OQ.0.5 \0 5 .•1/1 of .thanol..u .... haYing .1-6 ...........j'" 0.1 ell .f .CMUMnt ·hyd;&'o~i- 1.... a. t,be, :III••_.1..-h .....~h. v_to..... i8 carried ~ _ a pH of 7-10... ft •.::&. U"~UN between 8O-100oC f(r a perlod of Jr..alDut .... followed by .ahing an4 drying the _loure4I . .eub.~ra •• s dbta1ned.. '....... oa.... ua of aine, cadllll .. lead,. .aiokel, COppe.I:'" iftlln pco4uce OQ1oure4 ooa~.u. of thic ....of t.ha"-er of 3.7ra1crons and of colours reDQiriQfJ;'Olleny ~ black and various ahades of. yel10" can be oIlat.ateecl•... nett nta\alt floviftg froM ~he new f1Ddiiae 1. ---_1'1au attractive'shad •• rangino,:e- ; ...y \0 b*" ..,e1.10~. ~ ~ ~ ~ eha4ea .. 1t.ab1-e ,. .'I.I.~_.. a~t.~l'al ..,lic:at,1C1J\8 .• alum1ft1"· ... iU.•~.,., .can ... ·~ft. nove) t..-- o! t.be pl'eeant In..eri~iOB i. --- ·la···1 S 0 ,1 ••variou. ~cIe. ,.' 8~ .. J.11.1Uft1 .nd it. alloy. ca ..............111ahort. dU... ~10. , ... the 'bath. c.. ~ln1D9 cb~lr .".jlU1.t:a9recS1~a.~·h.flow ..... of the proo... ta .. fol1ow11.l'oU.h1D9 aDd tNffiDQ, ~,O.. Z'e8ae iri t.:1chlor;oechyl.e.~Gh1nQin~alkaliDe.-t. in nitric ac14 -, ...Wash in ~1nQ water.... 1n di.....1n ral1.ed vat.er .TAR .LD t.h. JlouriD9 .~lutiOD. .........otiRQ _~u'rh•• pp_~.DC. of fin1... pnHlUC*l ecoo&'dUlv t:O dalt .pr_nt. inven"..... i8 9Aet,lr ~, _ .. a ~.l ....... ceof the lMtal be1ft9 tl'.. ted. or,.. co~ eocuncuy np...<l\Ic. the aud._ concU.t10n of tbe un... l,. 1. ThUa, -.t1l'el y. ,<S1!fel"ent· affeet.. t:es.ult. frCllt ~ ...... oOlourift9 1I.1:'8aa._. )<S... .-tin9 Oft whet.herthe .... ~.l lie. bee p,......t-' PF c::.QlWent1onal. ".), rat.,- like acl,d cUpplll9, .h~ blaat.iIl9 ... rat-eat b.... ht."f.'l')'Ielol;1OwiftQ t,pical ...... 1.•• acre91.- 'to l11uKcuehOlll d'le pnacmt. 1nvent.lon 18 curled out. 1,nae:t.u.al P~bat IIOt. t.~ U.1Rlt. the .cope 01 this 1nv __ iOD•.... M ... 1(Mln1lMlM.- Al) ~UM1n~_ plat. •• ~_ ... "'~ t.d.Chloro .._h,l •• , .... In.an .lka11ne _lutton. coe~1D1 ..... 10 911so4l_ hJrdc01lide. 1'1.,.ed aJ)4 '~ ill 1. n1~C'ioacU·...... a" tb- ~~....r.ed iD the ~11OWs.-e ... 0.1 --' ... .lIltsOlut.iOn.- t3 •1 5 0 1 6 4A,mmon1umCarbonate • 20 g/l'I'd* ...... l.::.. ... , 1 mlll~~1nccarbonate : 0.4 g/lilH s 8.0 .t 0.51'emperature a 85 .± 2°C~Cmmer.i9p time~5minute.ColourLight grey.10 minutes Medium qrey&xtmp).e -2,~um1nium (containing l.~ Mo, ~est Al) panels werede9r~a8edw1~b acet.one etched in an acid $olution containinghydrci f luric acid • Nitric acid 1. we.ed and 1.... reed. inthe t allowing bath..a...etni-. carbonaterr1ethanol_ineMan9ane.. carbonate: 15 g/l'0.5 ml/l0.5 g/lpHTe.-perature ,7.5 .:t 0.595 .t 2°CColourLight yellow.. raion tiN3 minute.3.0 minute. Mediumyellow1 So ,~+lI.pl.. -3Q.\81nil8· (4.25~ Cu. "st Al) pJ.ates were degreased wi thtr1chloroe~lene and etched in a solution conta.lntn, ferric.ohlond. 100 &(1 HYdrochloric ac14 1So mill ·wub~. an4. .ll1meredin the tolclowinl S4>lutlon.""'nlum carbonate I 30 &11M. tbanolaJRine • 2 111/1Lead carbonate I 0.1 g/1JfI • 9.0 .t o.S1'emperature • 90 .:t' 2°C•~'nlRO tJ.S ID1nu~.10 minute.20 Jdnute.QplpurL1&bt yellowM.dium yel~Dark ,.e110w... pl, -ItAllaini\ll alloys ver••• re... d vital tr:LabJ,o.-etb71 ••etcbed 1n -" alkali aolutlon con ta1ninl 10 1/1 ......oartaon.t., 20 111 8041'* carbonate, 20 1/1 tri.di-J!ho8paate at 5'0°0 for 2 to- 3 lt1nutes II1d .~oll117 PDlt • .!to produce a 1'leaZ'l1' mrl'Or br1&bt tin1sh vatthe4 _4 tftatN.In the rolloving 8Olution.-.on1111 carbonate e 10 c/1Monoethll'l.lall1ne : 1 .1/1lickel carbOnat. : &r8-::t o.S 1/1- I 3.0 .t 0.'0"-lMIrature t 9S ,:t,2 C1•• nW M. ~1gur.3 .. u.tea Li.. t ,..,~-to,.lin'" flU-., -~• i#.'.~."'... ,," ,-ern' nlll i·..... Ii_· P~" _.· •• ' 0_ •• _ '0.504•• at.o.Ul.".r) weft degna..s. 1Itdi P'. 1IOIli_ ..801at.A. wa8hed et.ohecl 1n • eoluU.on CIOI'lt.d.D1aq SOgl1'erne .Cl'tlotS." 1n alii hJ*'odllone 'adel .. _ .....l~"" illl t.ha 1011OwiAcl aolutiol'u~S.\IIft Ca~te I 50 ..v1Dletl\aaol UIlne , 1 -1/1Copper C&&'bcmat.. , 0.2 ..vIpH : 9 .:t o.~'I'...,erature I 85 .t .pc",,1. §auper INr1tr aluainl .. pan8ls tlere degr .. _ed alkali,..etch_ &a • Mdt. tlreamx1de ·.lutton. cl.&ppe41ftlea Di~clc&Ct4 .. - 81ect.lOpolUhed anr1 a-,... 1i1UIe. .J 20 q/l1 1IlJ./,10.2 cVlTI'1ethanol •• neCaclmiu. cal'bonate J... ~.o.:t 0.595 .t aOc,.... M '7 7U'Nl.u .. '!ta.10 iUft\lt-sa..L1ght 91r4tYDan bJ:OMlftlah9"1!MJne1a Zc:c.mercial purl"" .•lu.a1n1~ alloya wen 4e9ne'" ....'a a$ tall ._l"'bl~'lUOd4e. 1~ utinc aCd4, _ .. - .•s.--C'..s 1n __• follOllltAQ bath.~a&- "&'boMte s .0 Q/l'l'&"le~l ...... i 2 ml/lMckel~~e , 0.1 g/l.-., .. ca~t..e : 0.1' 911- 16 -150164"aOM • 0.01 0119.± 3.597 .±2°CpH •Temperatare IlJl!!'er,lOP tim,5 minute,ColourLight black10 minute, Medium black20 minute, Nearly Jet. blacklxampl ••AJ.UI'\1nlumalloy. were dogrea.ed and pretreat.ed a, peeeX.Jml,le 7 wasl<.!d and ilTlT'lersed in th(~ £0110w1n9 bath.AmmoniumCarbonat. J 50 011, 2 ntl/l, O.l/WlJ 0.1 ;/1• 0.1 ;/1I 9.5 ..t 0••90 .± 20CColourJ..1Qht brownish greyMedium brownish greyDark browniah greyJet blackMonoethanolamineF•• rous carbonat.Copp.r cacbonat.NaOHpHTempec<"!tureIffi"'! rs 1on ti.m'5 minutes10 minut.s15 ..inut.s20 minut ••!)campl! 9Aluminium (1.~ mg, 0.6~ 51, O.25~ Cu, O.2~ Cr re.tdum1n1und alloys wera degruased and i'retreated a. 1n f-xampl... '"1 ..nd 11m1.rse'; in the follow1nQ bath.Ammoniumcarbonate .. 25 g/1D!ethanolami.1, • 1 ml/l&inc carbonate 0.1 ;/1Copper carbonat. • 0.1 011. HaOH • 0.01 011pH • 8.5 + ~597 +- C'l'8t'llPeratur. golouRi •••:1!M"F:!10n ;;tim, • yel-low~ ":::\;~ten' j fll8J,.lght greeniShMedium arAp.n1~h VA1'__1 5 0'1' •...-'-1. M.Sllpawed prooeu foe cbeIIl1c:el CDlau::la • .,al-uaiWA -' i~ alloy ".tnt.ee QlllpQa1fte the ....of poUahillg a-ff1 .. 4egnuMg •• UIa1iIM ~acid ~piftCJ ~c"'nt in •• ~cal .-.SInIJ_a.n• GOMi.~. 10 diet. ....... ~ -MKiOil ~".t ..10-10 ~1 ~ _2111_ ~-.. 0.01 .: 0.10 ell: '., cear.....of .... .. ...... Mag_._. 1.eecI, nicJla1, CGIIIt.... ,...•1",y er in. II htnet.l .. 0.5 - S -1/1 .. etbaDoJ.t ••ha.Me 1-' ....... --. ad 0.1.n of • __ h,...... ... - .. t_ chi ftal baUi _4 tit. ~N.t._t. 1. ~ ..Iat a ... of 1-10 at a t.~r.~ ..re bet.w.~ 8O-1od'c Ie• , .I.,f 011 1-. foll~ by ."~ .. ~~h._.NII I • tot..~"'"I. ..... .. cla~ sa cl.a. 1............... 1 ~· ieta ., ID elL .,. .' •• "'.-a.t ..,. ~ 0.4 "1 of au. •• WIlY"~... , •• t. M -en- -* ft ..... ~o .. ..... ..., • I ., H .. .,cte I. ~to is s1 •••). .. l •IUIP" p.-c_ ....... areal eel.",., &1,."1.. · a1~ ~ ~.u. .. ".1'....... , ·U~ ... M111a ~ .a••.DIll'"U.1' .M _.. _ex, I'"• ,e-·

An improved process for chemical colouring of aluminium and its alloys substrates

Abstract

Similar works

Full text

Available Versions

IR@CECRI