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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 725-5 : 1996 The Eu
2、ropean Standard EN 725-5 : 1996 has the status of a British Standard ICS 81.060.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Advanced technical ceramics Methods of test for ceramic powders Part 5. Determination of the particle size distribution This British Standard, hav
3、ing been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 August 1996 BSI 1996 The following BSI references relate to the work on this standard: Committee reference RPI/13 Draft for comm
4、ent 92/43966 DC ISBN 0 580 25837 8 BS EN 725-5 : 1996 Amendments issued since publication Amd. No.DateText affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee RPI/13, Advanced technical ceramics, upon which the follo
5、wing bodies were represented: AEATechnology Aluminium Federation British Ceramic Research Ltd. British Industrial Ceramic Manufacturers Association Department of Trade and Industry (National Physical Laboratory) Flat Glass Manufacturers Association GAMBICA (BEAMA Ltd.) Institute of Refractories Engi
6、neers Ministry of Defence Refractories Association of Great Britain Society of British Aerospace Companies Ltd. University of Manchester BS EN 725-5 : 1996 BSI 1996i Contents Page Committees responsibleInside front cover National forewordii Foreword2 Text of EN 725-53 ii BSI 1996 BS EN 725-5 : 1996
7、National foreword This British Standard has been prepared by the Technical Committee RPI/13 and is the English language version of EN 725-5 : 1996 Advanced technical ceramics Methods of test for ceramic powders Part 5: Determination of the particle size distribution, published by the European Commit
8、tee for Standardization (CEN). EN 725-5 : 1996 was produced as a result of international discussions in which the United Kingdom took an active part. NOTE. International and European Standards as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London, W
9、4 4AL Compliance with a British Standard does not of itself confer immunity from legal obligations. CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1996 All rights of reproduction
10、 and communication in any form and by any means reserved in all countries to CEN and its members Ref. No. EN 725-5 : 1996 E EUROPEAN STANDARDEN 725-5 NORME EUROPE ENNE EUROPA ISCHE NORM January 1996 ICS 81.060.10 Descriptors: Ceramics, powdery materials, grain size analysis, particle size, analysis
11、methods, sedimentation, radiation tests, laser radiation, diffraction English version Advanced technical ceramics Methods of test for ceramic powders Part5: Determination of the particle size distribution Ce ramiques techniques avance es Me thodes dessai pour les poudres ce ramiques Partie 5: De ter
12、mination de la distribution granulome trique Hochleistungskeramik Pru fverfahren keramischer Pulver Teil 5: Bestimmung der Teilchengro enverteilung This European Standard was approved by CEN on 1995-11-30. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the
13、conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in t
14、hree official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of
15、Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Page 2 EN 725-5: 1996 BSI 1996 Foreword This European Standard has been prepared by Technical Committee CEN/TC184, Advanced
16、technical ceramics, of which the Secretariat is held by BSI. EN 725 Advanced technical ceramics Methods of test for ceramic powders consists of 11 Parts: Part 1:Determination of impurities in alumina Part 2:Determination of impurities in barium titanate (ENV) Part 3:Determination of oxygen content o
17、f non-oxides by thermal extraction with a carrier gas Part 4:Determination of oxygen content of aluminium nitride by XRF (ENV) Part 5:Determination of particle size distribution Part 6:Determination of the specific surface area Part 7:Determination of absolute density Part 8:Determination of tapped
18、density Part 9:Determination of untamped density Part 10:Determination of compaction properties Part 11:Determination of densification on natural sintering (ENV) This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at
19、the latest by July 1996, and conflicting national standards shall be withdrawn at the latest by July 1996. According to the Common CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ice
20、land, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. Contents Page Foreword2 1Scope3 2Preparation of the suspension3 3Calibration3 4Procedure3 5Expression of results4 6Test report4 Annexes A(informative) Suspending liquids and dispersing agents
21、5 B(informative) Bibliography7 C(informative) Example of table recording suspension and dispersion7 D(informative) Example of particle size distribution8 E(informative) Example of representation of particle size distribution results as a table8 Page 3 EN 725-5: 1996 BSI 1996 1 Scope This Part of EN
22、725 describes the preparation of suspensions and calibration of apparatus, prior to the measurement of particle size distribution of powders used for advanced technical ceramics. The preparation is appropriate for measurements either by the sedimentation method, with the detection of X-ray absorptio
23、n, or the laser light scattering method. 2 Preparation of the suspension 2.1 Selection of liquid The dispersing liquid for the suspension shall not react with or dissolve the powder. For the sedimentation method, the density of the liquid shall be less than that of the powder by at least 0,5 g/cm3.
24、For the laser light scattering method, the liquid shall be optically transparent for the wavelength used. NOTE. This is generally 633 nm. The liquid shall have a refractive index which is substantially different from that of the sample. Any specific manufacturers instructions shall be considered. Th
25、e liquid for the suspension shall be selected, together with any dispersing agent, from those given in annex A. NOTE. Additional information is given in the references listed in annex B. The dispersion of powder in the liquid shall be checked by one of the methods given in 2.2. 2.2 Dispersion checki
26、ng 2.2.1 Optical microscopic examination A drop of the prepared suspension is placed on the glass slide of a microscope and is then carefully covered with a cover slip. The observation of the preparation with a suitable magnification allows one to determine if particles are completely separated and
27、well dispersed, or, if they are gathered together in chains or clusters. NOTE. This method is not suitable for powders with particle diameters 5 mm. 2.2.2 Qualitative test by sedimentation Allow the suspension to stand. A correctly dispersed suspension settles less rapidly than a suspension which fl
28、occulates, and shows no clear border line between the liquid which becomes clear and the layer which is still turbid as sedimentation proceeds. The sediment obtained is compact and of a minimal volume. 2.2.3 Scanning electron microscope examination (S.E.M.) Check the correlation of the particle size
29、 distribution obtained with the mean size of the ultimate particles observed by S.E.M. If the suspension is not sufficiently dispersed, particles are partially aggregated and particle size distribution measurements thus give values much higher than the mean size of the ultimate particles observed. 2
30、.2.4 Quantitative test by sedimentation Perform the quantitative tests, while allowing a variation of the various parameters liable to influence the dispersion quality and choose the dispersion procedure which gives the smallest mean particle diameter. An examination of the shape of the distribution
31、 can give an indication of the presence of agglomerates. 3 Calibration In order to check the apparatus, standard powders shall be analysed regularly. Suitable powders are available from the B.C.R. (Community Bureau of Reference). Their particle size distribution is expressed in the form of cumulativ
32、e curves. If dispersion and test conditions are rigorously identical for the successive analyses of standard powders, the lack of curve deviation gives an indication of the good working order of the apparatus. As the curves of the standard powders are given as equivalent Stokes diameters, those obta
33、ined from the sedimentation method by gravity and detection of X-ray absorption should be comparable. Four of these reference powders show a particle size distribution in the range of 0,1 mm to 100 mm; their characteristics are summarized in table 1. Table 1. Standard reference powders ReferenceType
34、Size range CRM 066Quartz powder 0,35 mm to 3,50 mm CRM 067Quartz powder 2,4 mm to 32 mm CRM 069Quartzic sand14 mm to 90 mm CRM 070Quartz powder 1,2 mm to 20 mm For more information, contact: Community Bureau of Reference, Directorate General for Science, Research and Education Rue de la Loi, 200 Bru
35、ssels B 1049. 4 Procedure 4.1 Determine the quantity of powder, the type and quantity of suspending liquid and the dispersing agent to be used. In principle, and within the limits imposed by the instrument, the sample mass to be dispersed has no influence on the results. However, it is preferable to
36、 use dilute suspensions. For the laser light scattering method, for all determinations to be accurate, all particles present in the pencil rays need to be separate and diffract independently from each other. This condition should be fulfilled when each particle with a radius a is in the centre of a
37、circle with a radius R = a, when there is no secant circle and when no particle casts a shadow on the others. Page 4 EN 725-5: 1996 BSI 1996 If particles travel through the laser beam inside a liquid film of thickness e, the maximum sample quantity is given by: Qm= r V 4 3 a2 a e where a= mean radiu
38、s of particles (mm); e= liquid film thickness (mm); r= sample density (g/cm3); V= total volume of carrier liquid (cm3); a= proportionality factor; Qm= maximum sample quantity (g). 4.2 In a 50 ml to 100 ml beaker prepare a first test sample. Mix the suspending liquid and the dispersing agent, add the
39、 powder while stirring the suspension, and disperse ultrasonically until free of agglomerates. Continue stirring with a magnetic agitator until the start of the analysis. 4.3 Read the technical instructions of the instrument for general adjustments prior to the test, and perform the test following t
40、he manufacturers recommendations. Repeat the procedure on a second test sample and plot the particle size distribution curves. If both curves are sufficiently similar, this allows one to ascertain that the dispersion is stable and that no mistake has been made during the test. If the curves are not
41、similar, check the dispersion again (see 2.2). 5 Expression of results Record the suspension and dispersion conditions in a table similar to the example given in annex C. Present the results either in graphic form as in annex D, with the cumulative particle size distribution curve obtained automatic
42、ally on the measurement sheet of the instrument, specifying test conditions in the appropriate part of the sheet, or as a table of results. A recommended layout example is given in annex E. 6 Test report The test report shall contain the following information: a) the name of the testing establishmen
43、t; b) date of the test, unique identification of report and of each page, customer name and address and signatory; c) a reference to this European Standard, i.e. determined in accordance with EN 725-5; d) a description of the test material (manufacturer, type, batch or code number, date of receipt)
44、including any treatment before testing; e) the suspension and dispersion conditions in the form of a table similar to the example given in annex C; f) the reference powder used to calibrate the instrument (see clause 3) and the results obtained on a given date; g) for the sedimentation method only,
45、the apparent density of the powder, apparent density and viscosity of the suspending liquid, displacement rate of the cell, temperature of the suspension and the initial diameter; h) comments about the test or test results. Page 5 EN 725-5: 1996 BSI 1996 Table A.1 Suspending liquids and dispersing a
46、gents MaterialSuspending liquidDispersing agent (0,5 g/l to 1,0 g/l, unless otherwise stated) Aluminasee aluminium (oxide) Aluminium (oxide)waterSodium pyrophosphate waterSodium pyrophosphate waterSodium tartrate waterd.a. No. 3 or No. 4 or No. 5 or No. 9 waterhydrochloric acid (pH 3) n-butanol n-bu
47、tylamine linseed oil/xylene iso-octaned.a. No. 6 Barium carbonatecyclohexanol, methanol Barium titanatewaterd.a No. 8 Boron (amorphous)n-butanol n-butanol/ethanol (various mixtures) Boron carbidewatersodium pyrophosphate n-butanol/ethanol (various mixtures) Boron nitriden-butanol n-butanol/ethanol (
48、various mixtures) Boron oxidewatersodium pyrophosphate Chromium oxidewatersodium phosphate cyclohexanol/isoamyl alcohol (9 : 1) (v/v) (0,1 g/l to 0,3 g/l) Corundumsee aluminium oxidesodium pyrophosphate Diamond (powder)olive oil gelatine in water (1 g/l to 2 g/l)sodium carbonate (pH 9) ethanol water
49、trisodium orthophospate Graphitewater0,5 g/l tannic acid water0,5 g/l d.a. No. 1 or No. 8 water5 g/l sodium linoleate (0,88 ml/l to 3,5 ml/l) water/ammonia ethanol n-butanol Annex A (informative) Suspending liquids and dispersing agents The following alphabetical list in table A.1 gives examples of suspending liquids and dispersing agents most commonly used for the main technical ceramic powders. Surface characteristics, and consequently dispersion behaviour, depend on the powder type, but also on its manufacturing process. Therefore,