1、BRITISH STANDARDBS EN 725-10:2007Advanced technical ceramics Methods of test for ceramic powders Part 10: Determination of compaction propertiesThe European Standard EN 725-10:2007 has the status of a British StandardICS 81.060.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g4
2、0g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 725-10:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2007 BSI 2007ISBN 978 0 580 54528 3N
3、ational forewordThis British Standard is the UK implementation of EN 725-10:2007. It supersedes BS EN 725-10:1997 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee RPI/13, Advanced technical ceramics.A list of organizations represented on this committee
4、can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationA
5、md. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 725-10September 2007ICS 81.060.30 Supersedes EN 725-10:1997 English VersionAdvanced technical ceramics - Methods of test for ceramicpowders - Part 10: Determination of compaction propertiesCramiques techniques avances - Mthodes d
6、essai despoudres cramiques - Partie 10: Dtermination desproprits de compactionHochleistungskeramik - Prfverfahren fr keramischePulver - Teil 10: Bestimmung derVerdichtungseigenschaftenThis European Standard was approved by CEN on 11 August 2007.CEN members are bound to comply with the CEN/CENELEC In
7、ternal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN mem
8、ber.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members
9、are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switze
10、rland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 72
11、5-10:2007: EEN 725-10:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Principle4 4 Symbols 4 5 Apparatus .4 6 Procedure .5 6.1 Drying5 6.2 Quantity 5 6.3 Cleaning of the die and punches .5 6.4 Powder testing conditions5 6.5 Lubrication .5 6.6 Compacting pressures6 6.7 Compact
12、ing and ejection 6 7 Expression of results 7 7.1 Calculation7 7.2 Compaction curve7 8 Test report 7 Annex A (informative) Repeatability and reproducibility 11 Annex B (informative) Example of presentation of test report .12 B.1 General12 B.2 Sample description and preparation .12 B.3 Test conditions
13、 12 B.4 Determination of the density of the compacts .13 B.5 Calculation of density .13 Bibliography 14 EN 725-10:2007 (E) 3 Foreword This document (EN 725-10:2007) has been prepared by Technical Committee CEN/TC 184 “Advanced technical ceramics”, the secretariat of which is held by BSI. This Europe
14、an Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2008, and conflicting national standards shall be withdrawn at the latest by March 2008. Attention is drawn to the possibility that some of the elements
15、of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 725-10:1996. EN 725 Advanced technical ceramics Methods of test for ceramic powders was prepared in parts as follows: Part
16、 1: Determination of impurities in alumina Part 2: Determination of impurities in barium titanate Part 3: Determination of the oxygen content of non-oxides by thermal extraction with a carrier gas Part 4: Determination of oxygen content in aluminium nitride by XRF analysis Part 5: Determination of p
17、article size distribution Part 6: Determination of the specific surface area withdrawn Part 7: Determination of the absolute density withdrawn Part 8: Determination of tapped bulk density Part 9: Determination of un-tapped bulk density Part 10: Determination of compaction properties Part 11: Determi
18、nation of densification on natural sintering Part 12: Chemical analysis of zirconia Parts 6 and 7 of the series were superseded in 2005 by EN ISO 18757 and EN ISO 18753 respectively. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries ar
19、e bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Swed
20、en, Switzerland and the United Kingdom. EN 725-10:2007 (E) 4 1 Scope This Part of EN 725 describes methods for the determination of the compaction behaviour of ungranulated or granulated ceramic powders, when subjected to uniaxial compressive loading in a rigid die, under specified conditions. 2 Nor
21、mative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO/IEC 17025, General requi
22、rements for the competence of testing and calibration laboratories (ISO/IEC 17025:2005) 3 Principle The powder is compacted uniaxially in a rigid die by double-action pressing. Samples of the powder may be pressed either at a single pressure or at a series of pressures. After ejection from the die,
23、the apparent geometrical density of the compact is determined. Where one pressure is used, the density obtained represents the compaction properties of the powder at that pressure. Where more than one pressure is used, the densities obtained are utilized for drawing the compaction curve of the powde
24、r, which is a plot of its density as a function of the compacting pressure. 4 Symbols The symbols and associated units used in this part of EN 725 are set out in Table 1. Table 1 Symbols and units Symbol Designation Unit geom m V Apparent geometrical density Mass of the compact Volume of the compact
25、 kg/m3 g cm3If the apparent density is measured at one pressure only, for example 200 MPa, the symbol becomes, e.g. geom (200). 5 Apparatus 5.1 Die, which shall be made from hard material (e.g. tungsten carbide). The cylindrical die shall contain two punches for producing cylindrical compacts and sh
26、all be of the floating type or of the type suspended from a spring. The die shall be capable of making compacts of diameter 20 mm to 26 mm with a height to diameter ratio between 0,3 and 0,5, with tolerances as indicated in Figure 1. The upper part of the die shall be (preferably) designed to avoid
27、damage to the compact during the ejection phase due to springback. An ejection cone of height 5 mm, allowing an increase of the diameter at the top of the die of approximately 1 %, as shown in Figure 1, should be used. EN 725-10:2007 (E) 5 The die may be fitted with a venting valve. 5.2 Press, capab
28、le of applying sufficient force with an accuracy of 1 %. 5.3 Balance, capable of weighing at least 10 g, to the nearest 0,005 g. 5.4 Micrometer, conforming to ISO 3611, or other suitable measuring device for measuring the dimensions of the compacts with a resolution of 0,01 mm. 6 Procedure 6.1 Dryin
29、g A sample containing organic additives shall be used as received. A sample without organic additives shall be dried at 110 C 5 C until constant mass is attained. Store in a desiccator until the test is performed. During drying the sample layer shall have a maximum thickness of 5 mm. 6.2 Quantity Th
30、ree compacts with dimensions as specified in 5.1 shall be prepared for each pressure used in the determination. The quantity of powder shall be sufficient for the preparation of the total number of compacts (3 x the number of pressures used). NOTE If necessary, preliminary tests should be made to es
31、tablish the quantity of powder necessary to conform to this requirement. 6.3 Cleaning of the die and punches Wipe the die cavity and the punches with a soft, clean paper towel soaked with an appropriate solvent, such as acetone. Allow the solvent to evaporate. 6.4 Powder testing conditions Powders s
32、hall be compacted: either 1) in a dry die NOTE For powders not containing a lubricant, seizure and excessive die wear may occur, particularly at high compacting pressures or 2) in a die with lubricated walls (see 6.5), or 3) in a dry die, after mixing a lubricant with the powder (see 6.5.3). 6.5 Lub
33、rication 6.5.1 Lubrication of the die walls or of the powder is likely to modify the compaction results. Similarly, depending on the type and quantity of lubricant added to the powder, the results may vary within wide ranges. EN 725-10:2007 (E) 6 The test report (see Clause 8) shall therefore mentio
34、n whether or not lubrication had taken place, and if the lubrication was carried out on the walls of the die or on the powder. Use one of the following two methods (see 6.5.2 and 6.5.3) if lubrication is applied. 6.5.2 To lubricate the die wall, apply a mixture or a solution of a lubricant in a suit
35、able volatile organic liquid, for example 20 g of stearic acid in 980 g of acetone. After any excess liquid has drained away, allow the solution adhering to the walls to evaporate leaving a thin layer of lubricant. Alternatively, press in the die, before testing, inert spheres (polyurethane spheres
36、for instance) coated with lubricant. After removal of the pressed disc of inert material, a thin layer of lubricant remains on the walls of the die. 6.5.3 Lubricate the powder to be tested by thoroughly mixing it with an appropriate amount of a suitable solid lubricant (for example zinc stearate or
37、stearic acid). 6.6 Compacting pressures For plotting the compaction curve of a powder, a minimum of four pressures in a range agreed between the parties concerned shall be used. If compaction properties are to be determined at a single pressure only, this pressure shall also be agreed between partie
38、s prior to the test. 6.7 Compacting and ejection 6.7.1 Position the die using spacers between the die and the foot of the lower punch, to leave a free volume in the die large enough to contain the bulk powder (see Figure 2). 6.7.2 Pour a known weight of powder into the die, sufficient to almost fill
39、 the die cavity. The weight shall be the same for each compact in a series. 6.7.3 Remove any remaining powder adhering to the wall of the die cavity. 6.7.4 Insert the upper punch into the die. 6.7.5 Position the die with its punches between the plate ends of the press. Apply and release a preliminar
40、y pressure. This pressure shall be lower than the lower pressure used in the test. Remove the spacers supporting the die. NOTE 1 If the die is supported by springs or by a similar system, it is unnecessary to apply this preliminary pressure. Apply the selected test pressure and maintain for 1 min. N
41、OTE 2 Taking into account the different press technology, it is difficult to specify a rate of increase of the force as well as the displacement speed of the punch. 6.7.6 Perform decompression slowly (for example 10 mm/min) to avoid breaking the compact. 6.7.7 Eject the compact by using a relative m
42、ovement between the die and the lower punch. Transfer the compact to a desiccator for 1 h to allow a possible expansion due to springback. Remove the compact from the desiccator, weigh to the nearest 0,005 g and measure to the nearest 0,01 mm, the dimensions (both height and diameter) in 3 different
43、 places, and take the average. EN 725-10:2007 (E) 7 7 Expression of results 7.1 Calculation The apparent geometrical density of the compact is given by the equation: Vmgeom= (1) where: m is the mass of the compact, in grams; V is the volume of the compact, in cubic centimetres. Calculate the apparen
44、t geometrical density in grams per cubic centimetre and then convert the answer to kilograms per cubic metre, expressed to the nearest 20 kg/m3. Express the compaction properties for a given compacting pressure as the average of the three density figures, calculated to the nearest 20 kg/m3, obtained
45、 at the compacting pressure. 7.2 Compaction curve Draw the compaction curve of a powder through points representing the average of determinations of geom at each of the pressures tested. 8 Test report The test report shall be in accordance with the reporting provisions of EN ISO/IEC 17025, and shall
46、 include at least the following information: a) name and address of the testing establishment; b) date of the test; c) on each page, a unique report identification and page number; d) customer name and address; e) reference to this standard, i.e. determined in accordance with EN 725-10; f) authorizi
47、ng signature; g) any deviation from the method described, with appropriate validation, i.e. demonstrated to be acceptable to the parties involved; h) description of the powder (e.g. material type, manufacturer code, batch or code number); i) type, nature and amount of lubricant and any other organic
48、 additives used in the test, including: 1) lubrication of the die walls, or no lubrication; 2) lubrication of the powder, or no lubrication (state how the lubricant has been added); 3) other organic additives; EN 725-10:2007 (E) 8 j) compacting pressures and compaction cycle used; k) dimensions of t
49、he compacts; l) results obtained including the compaction curve; m) any comments about the test or test results. EN 725-10:2007 (E) 9 Dimensions in millimetres 251004512= 60-80H16341,61,62,524R550152 x 451525 l0,01 A0,01 ATAKey 1 shrink ring 2 hard material 3 upper punch, l = H - 10 4 lower punch, l = H + 35 Figure 1 Example of tooling to produce a cylindrical compact EN 725-10:2007 (E) 10 123Filing Pre-compacting Compacting Ejection Key 1 powder 2 ejection cone 3 spacer Figure 2 Diagram of powder compacting operations EN 725-10:2007
