इंटरनेट मानक Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. “जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न’ 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 7512 (2006): Method for the determination of average particle size of metal powders by fisher sub-sieve sizer [MTD 25: Powder Metallurgical Materials and Products] “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda ““IInnvveenntt aa NNeeww IInnddiiaa UUssiinngg KKnnoowwlleeddggee”” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” I I I I I I IS 7512:2006 / Indian Standard METHOD FOR THE DETERMINATION OF AVERAGE PARTICLE SIZE OF METAL POWDERS BY FISHER SUB-SIEVE SIZER (First Revision) ICS77.160 ., \ 0 BIS 2006 BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 June 2006 Price Group 2 . ... Powder Metallurgical Materials and Products Sectional Committee, MTD 25 FOREWORD This Indian Standard (First Revision) wasadopted bythe Bureau ofIndian Standards, after the draft finalized bythe Powder Metallurgical MaterialsandProducts SectionalCommitteehadbeenapproved bytheMetallurgical Engineering Division Council. This standard wasfirstpublished in 1974.Whilereviewingthisstandard inthe lightofexperience gainedduring these years, the Committee decided to revise itto bring it in line with the present practices followed in determination of average particle sizeofmetal powders by Fisher sub-sieve sizer. Inpreparation ofthis standard assistance hasbeen derived fromthe following a) ASTM B330-1998 ‘StandardtestmethodforaverageparticlesizeFishernumberofmetalpowdersofrefractory metal andtheir related compound byFisher sub-sieve size’ b) 1S0 10070:1991 ‘Metallic powder — Determination ofenvelope specific surface area frommeasurement of permeability to air of apowder bed under steady stateflowcondition’. c) MPIFStandard—Method fordetermination ofaveragepartial sizeofmetalpowder usingthisFishersub-sieve size In reporting the result of a test or analysis made in accordance with this standard, if the final values, observed orcalculated, isto berounded off, itshallbe done inaccordance with IS2: 1960 ‘Rules for rounding offnumerical values(revised)’. IS 7512:2006 Indian Standard METHOD FOR THE DETERMINATION OF AVERAGE PARTICLE SIZE OF METAL POWDERS BY FISHER SUB-SIEVE SIZER (First Revision ) 1SCOPE 3.4 De-agglomeration — Process used to break up agglomerates ofpractices. 1.1 This standard prescribes the method of determining the average particle size of metal powder by Fisher 3.5 Fisher Number — Acalculated value equated to an sub-sieve sizer. average particle diameter, assuming all the particles are spherical and of uniform size. 1.2 This test method uses air permeability to determine anenvelopespecificsurfaceareaanditsassociatedaverage 3.6 FisherCalibrator ‘lkbe — Ajewel with aprecision equivalentsphericaldhuneter ofmetalpowdersandrelated orifice mounted in atube similar to a sample tube. The compounds. The powders may be analyzed in their as calibrator tube value is directly traceable to the master supplied(shipped,receivedorprocessed)conditionoratler tube maintained by Fisher. theyhavebeende-agglomerated ormilledbyalaboratory procedure. The values obtained are not intended to be 3.7 Porosity of a Bed of Powder — The ratio of the absolute but are generally usefid on a relative basis for volume ofthe void space inthe powder bedtothatofthe control purposes. overall volume ofthe powder bed. 2REFERENCES 3.8Agglomerate — Several particles adhering together. The standards listed below contain provisions, which through reference inthistext constitute provisions ofthis 4PRINCIPLE OF TEST standard.Atthetimeofpublication, theeditions indicated werevalid.Allstandardsaresubjecttorevisionsandparties 4.1 This test method provides a procedure for .toagreements based on this standard are encouraged to determiningtheenvelope-specific surfaceareaofpowders investigate the possibility of applying the most recent which is equated to an average particle diameter by editions ofthe standard indicated b elow: calculation assuming the particle are monosize, smooth surface, non-porous spherical particles. For this reason, 1SNo. Title values obtained by this test method will be defined asa 5432:1982 Glossary of terms relating to powder Fisher number. The degree of correlation between the metallurgy @W revision) results of this test method and the quality of powders in usewillvarywitheach particular application andhasnot 6492:1972 Methods for sampling of powders for been filly determined. powder metallurgical purposes 4.2 This test method isgenerally applicable to all &d 3TERMINOLOGY powders and related compounds, including -carcides, For the purpose of this standard, the definition given in nitridesandoxides,forparticleshavingdiametersbetween IS5432 andthe following shall apply. 0.2and50pm.Itshouldnotbeusedforpowderscomposed of-particles whoseshape istoo farfrom equiaxed, that is, 3.1 Fisher Sub-sieve Sizer — Acommercially available flakesorfibres. Inthese cases, itispermissibleto usethe permeability instrument for measuring envelope-specific test method described only by agreement between the surfacearea. parties concerned. Thistest method Shallnotbeusedfor 3.2 Envelope-Specific. Surface Area — The specific mixturesofdifferent powders,nor forpowderscontaining surface area of a powder as determined by gas binders or lubricants. When the powder contain permearnetry. agglomerates, themeasured surface areamaybeaffected bythedegree of agglomeration. 3.3 Air Permeability — Themeasurement ofairpressure drop across apacked bed of powder. 4.3Whenanaverageparticlesizeofpowdersisdetermined 1 IS 7512:2006 using the Fisher sub-sieve sizer, itshould be clearly kept e) Rubber sample tube seals shallnot be worntothe in mind that this average size i-sderived from the point where leakage occurs; determination of the specific surface area of the powder o Sample packing post shall beproperly adjusted; usingarklationsiiipthatistrueonlyforpowdersofuniform . sizeand spherical shape. !3 Drying agent shall be inproper condition; and h) Manometer and standpipe levelsshallbechecked. 5APPARATUS 6;1.1 Adjustthemanometer onlywhenthemachineisnot 5.1The Fishersub-sieve sizer consists ofanairpump, an operating andwiththe pressure-released for minimum of air-pressurereglatingdevice,aprecision-bore sampletube, 5minto allowthe manometer tube to drain complete. astandardizeddoublerangeairflowmeter,andacalculator chart. Included is accessoty equipment consisting of a 6.2 Thestandardization oftheFishersub-sievesizer-shall plug manipulator, powder fimnel, two porous plugs, a be made using the Fisher jewel calibrator tube (jewel supplyofpaper disks, and arubber tube support stqnd. orifice tube) astheprimary standard. Specification shall bemade atboth ranges ofthe machine. NOTE —-Necessary replacementpartsshouldbeobtainedfrom TheFisherjewel calibrator tube used for standardization themanufacturer,especiallyinthecaseoftheprecisionmanometer whichisapart oftheairflowmeter. shallbecheckedunderamicroscope atleastonceamonth todetermine the condition and cleanliness oftheorifice. 5.2 The manufacturer also furnishes directions which Iftheorifice is notclean,clean.asdescribed intheFisher should be followed except as amended as follows. sub-sieve sizer instruction manual. Particularattentionshouldbegiventopropermaintenance oftheinstrument withspecial reference totheinstructions 6.3 Withthe sub-sieve sizer properly adjusted andsetto on: (a)periodic checking ofthewaterlevelinthepressure theproper range, proceed follows: regulatorstandpipe,(@manometer levelbeforethesample tube isinserted, and (c) the sample packing assembly. a) MounttheFisherjewel calibrator hibebetweenthe rubber seal supports just to the right of the brass 5.3 Jewel Calibrator Thbe post. Clamp theupper cap down onto thetube so that anairtight seal isobtained atbothends.., Astandardforaverageparticlesizemeasurement. Itallows operatorstorelatetheirdatatothatofotheranalysts. Each b) Adjust the calculator chart so that the porosity calibrator isfactory tested three times with the resulting reading corresponds to the value indicated on the readings and associated porosity recorded onthetube. jewel calibrator use. c) Switchonthemachine andallow ittowarmupfor NOTE — Adjustthesamplepackingassembly(a)asdescribedin aminimum of20.min. Adjustthepressure control themanufacturer’sdirectionswiththe exceptionthattheplugsand knob, located nearthebubble observation window paperdisksarcnotinsertedinthesampletubebutarcmerelystacked togetherandplacedbetweenthebrasss upportandthe‘flat’ ofthe atthe lower leflofthepanel, untilthebubbles rise bottomoftherack,of (b) aspreviouslydescribedexceptthata inthe stand pipe at the rate of 2to 3bubbles per speciallymadebaselinegaugeisusedinsteadoftheplugsand second. Thiswillcausethe waterlinetoriseabove paperdisks.Thisbaselinegaugeshallhaveaheightof 19,30* the calibration mark onthe upper end ofthe stand 0.10 mm.Checkallplugheightswhennewplugsarepurchased andperiodicallythereaftertomakesureallareequalinheight. pipe. This is normal and does not mean the calibration isinerror. 5.4 Balance d) The liquid level in the manometer tube will rise Having a capacity of at least 50 g and a sensitivity of slowlyuntil itreaches amaximum. Allowatleast 0.001g. 5minforthistohappen. Attheendofthisperiod, usingcarenotto disturb thechart, turntherackup 6STANDARDIZAT-1ON OF APPARATUS untiltheupper edgeofthecrossbar coincideswith thebottomoftheliquidmeniscusinthemanometer. 6.1Beforeproceedings withstandardization oftheFisher The Fisher number isindicated bythe location of sub-sieve sizer,the following itemsshallbe checked: the pointer tip in relation to the curves on the a). Chart shall be properly aligned horizontally with calculator chart. Record the ambient temperature the indicator pointer; tothenearest 1“C. Releasetheclampontheupper b) Rackad pinionshallbeprcpe#y alignedvertically endofthetube slowlysothemanometer returnsto withthe chart; itszero position slowly with very littleovershoot. c) Sampletube orplugs shallnot be worn; This limitsthe formation of liquid droplets onthe inside ofthe manometer tube. d) Manometer andairresistors shallbefreeofvisib le contamination; e) Thevalueobtained inthemanner mustcorrespond 2 1S7512:2006 to the Fisher number indicated on the jewel until itisevenwiththe endofthe sampletube. Placethe calibrator tube within + 1percent. sample tube in a vertical position in a support with the paper sideofthe plug up. 0 IftheFishernumber valueasindicated onthechart does not correspond to + 1percent of the value indicated onthejewel calibrator tube,calibrate the 7.3.3 Determine the Mass of the Sample sub-sieve as follows: Withtheaidofthepowder fimnel,completelytransferthe xample intothe sample tube, tapping the sideofthetube Adjusteitherthehighneedlevalveorthelowneedle and fimrtel2 or 3 times each to settle the powder. Laya valve as required to bring the Fisher number second paper disk over the top of the sample tube, and indicated onthe charttothe value indicated onthe usingartotherporous brassplug, forcetheplug andpaper jewel calibrator tube. After adjustment is made, disk down into the sample tube until it isjust inside the repeat 6.3(d). sample tube. Place the sample tube on the brass post NOTE – Becauseonly oneflow meter isusedforthelow beneaththerackandpinion withthelowerplugincontact (0.2to20.0 ~m)Fishernumberrange,whilebothflowmeteFs withthe upper end ofthe brass post. areusedfortirehigh(20.0 to50.0 pm)Fishernumberrarrge, thelowrangeshouldbestandardizedfirst. Atlerthelowrange isstandardized,thehighrangeisthenstandardized,making 7.3.4 Lowet%herack, guiding ituntiltheflat-bottom end adjustmentsonlytotheoneflowmeteropenedupbytherange- comes in contact with the upper plug. Pack the sample controlknob. firmly by turning down the pinion knob with the torque wrench or torque screwdriver until a compressive force 9 Standardization with the jewel calibrator tube is of222N(50lb~ isapplied tothesample. Ailer thisforce recommended before and after any series of isapplied,thesampletubeshouldnotbetouchingtheblock determinations or at least very 4 h of continued in which the brass post is mounted. In cases where the operation. Warmupofthemachine isrequired ifit tube tends to move down and kept on the block during hasbeen offfor more than 30min. compression, thetube canbeheldtemporarily byhandor aspacer can beused until most ofthe compressive force 7PROCEDURE has been applied. The spacer isthen removed when the maximum force is actually applied, Apply and release 7.1Temperature of Test maximum force atotal ofthe three times. After the load Make Fisher number determinations with * 2°C of the maximum compression force hasbeen applied, checkthe temperature at which standardization of the Fisher rack to make sure ithas not been removed upward with sub-sieve was made. Re-standardize, ifthe temperature the final release of pressure. Check torque wrench or ofthetest variesmore than+ 2°C. torque screwdriver forstandardization atleastonceevery month using sample pressure calibrator or anequivalent 7.1.1 Thesamplingofpowder for c onducting thetestshall device. be inaccordance with IS 6492. 7.3.5 Shiftthecalculator chart laterally untiltheextreme 7.2 SizeofTest Sample tip of the pointer just coincides with the sample height The massofthe sample used for tests should be equal in curveonthechart. Thepointer shouldbemidwaybetween grams (within + 0.01 g) to the theoretical density of the the top and bottom of the line. The chart must not be powder(Tungsten, 19.3g; molybdenum 10.22g;tantalum movedafterthissettinguntilthedetermination kfmished. 16.6g,etc). Record the porosity value indicated atthe bottom ofthe chart. 7.3 Fisher Number Determination 7.3.6 Without disturbing the sample m any way,mount The Fisher number determination shall be made by the the sample tube between the rubber cushioned supports same operator who make the standardizations, and is just to the right of the brass post. Clamp the upper cap startedatlerstandardizationorthedeterminationofanother down onto the sample tube so that an airtight seal is sample. Proceed asfollows. obtained atboth ends. 7.3.1 Withthe sub-sieve sizer properly adjusted, set the NOTE — Thesampletubemayeventuallywearandcausefaulty range control to the range desired. values.Whenthisconditionissuspected,repla~ ttfetube.Sample tubewithobviouswearorscratches,orboth,shouldbediscarded. 7.3.2 Lay a paper disk over one end of the sample tube usingoneoftheporous plugswiththeperforated surfaces 7.3.7 Determine the Fisher number, switching on the of the plug against the surface of the paper disk. This machine and allowing the liquid level inthe manometer crimpsthepaperaround theedgesandthepaperpreced es tubetoriseuntilitreachesamaximum. Allowaminimum theplug intothesample tube. Pushtheplug intothetube of5minforthistohappen. TheFishernumberisindicated 3 I IS 7512:2006 bythe location of the tip of the pointer in relation to the Ijx I(Y5 curves on the calculator chart. Record this value along d.— (5) SV with the porosity for the sample and the ambient temperature atwhich the measurement wasmade. . Acalculationofanequivalentsphericaldiameterbasedonthis equationisperformedautomaticallybythecalculatorchartof NOTE—Formulas forc~lculating the Fisher number or the theFishersub-sievesizerfromthevaluesrelatedtotheporosity equivalentsphericaldiameterandporosityvaluesfromsampleand andtothepermeability ofthepowderbedmeasuredbythe manometerheightsareasfollows: instmment. In other words, what is determinedwith the instrumentisthespecificsurfaceareaofthepowder,Whenan a) Wheresamplemassisequaltothetheoreticaldensityofthe equivalentsphericaldiameterisdeterminedusingtheFisher materialbeingtested: sub-sievesize, it shouldbe clearly kept in mind that this equivalentsphericaldiameterisderivedfromthedetermination (LA-1) ~d Porosity = ~ . (1) ofthespecificsurfaceareaofthepowderusingarelationship thatistrueonlyforprrwdersofuniformsizeandsphericalshape. Hence,theterm ‘Fishernumber’ispreferredtodescribethe Fishernumber,pm = CL=, ..... (2) resultsQfthisteat,ratherthanparticlesizeorequivalentspherical diameter. where L = sampleheightatlercompaction,incm; SREPORTING OF RESULTS A = cross-sectionaalreaofthesampletube,cm’(=1.267cm’); M = massofsamplefor 1cm]; D = theoreticaldensityofmaterialbeingtested,in#cm]; 8.1 ReporttheFishernumbervalueofassuppliedpowders C = cross-sectionalconstant=3.80; as the average of two determinations, each made on F = pressuredifferenceofwater,cm(NOTE F =2H, where separate portions of the sample, ifthe two values agree H= heightofwatercolumnabovebaseline,incm} and P = overallairpressure(determinedbystandpipe)= 50cm within 3 percent. If the values do not agree within ofwater. 3 percent. If the values do not agree within 3 percent, review the equipment and procedure arrdrepeat the test b) Wheresamplemassisnotequaltothetheoreticaldensityof usingseparate portions ofthesample. Reporttheaverage materialbeingtested,asinthecasewhenthesamplesizeis porosity of the checked samples alongwith the average lessthanthetubedensity: Fishernumber,andidenti~ thevaluesasbeingdetermined (LA- M) onassupplied powder. Porosity = + ,and (3) 8.2 If the powder is de-agglomerated or milled in the laboratory prior to analysis m accordance with practice CL144 . (4) onlyonedeterminationoftheFishernumber,needbemade D (P- F)(At-M/D)3 andreported along withtheporosity valuedetermined as identified as lab milled. If another laboratory method it where M = massofsample,in~ and was to de-agglomerate or mill the powder, suftlcient D = tmedensityofmaterialbeing tested,ing/cm3 informationto described the procedure completely must alsobe included withthe results. Forapowderinwhichallparticlesaresphericalandofuniform size,theparticlesidedin micrometersmaybecalculatedfrom thevolume-specificsurfaceareaS,bythefollowingformula 8.3Table 1provides limitations ofFishernumber. Table 1 Reporting Limitations SI RangeFisher Porosity Range ChartDivision Readand No. Number Control (Fisher Reportto Number) FisherNumber (1) (2) (3) (4) (5) (6) i) 0.2to0.5 0.60to0,70 Readdirect o.I 0.1 ii) 0.2-0.5 0.70-0.80 Readdirect 0.1 0,05 iii) 0.5-1.0 0.55-0.80 Readdirect 0.1 0.02 iv) 1.0-4.0 0.45-0.80 Readdirect 0.1 0,02 0 4.0-8.0 0.40-0.80 Readdirect 0.2 0.05 vi) 8.0-15.0 0.40-0.65 Readdirect 0.5 0.2 vii) 15.0-20,0 0.40-0.75 Readdirect I.0 0,5 viii) 20.0-50,0 0.40-0.60 Readdirect I.0 0.5 4 -. Bureau of Indian Standards BIS is a statutory institution established under the Bureau of Indian Standards Act, 1986 to promote harmonious development of the activities of standardization, marking and quality certification of goods and attending to connected matters inthe country. Copyright BIS has the copyright of all its publications. No part of these publications may be reproduced in any form without the prior permission in writing of BIS. 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