1、Designation: B330 07 B330 12Standard Test MethodMethods forFisher Number Estimating Average Particle Size of MetalPowders and Related Compounds Using Air Permeability1This standard is issued under the fixed designation B330; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Def
3、ense.1. Scope Scope*1.1 ThisThese test method usesmethods use air permeability to determine an envelope-specific surface area and its associatedaverage equivalent spherical diameter (from 0.50.2 to 50 m) 75m) of metal powders and related compounds. The powders maybe analyzed in their “as-supplied” (
4、shipped, received, or processed) condition or after they have been de-agglomerated or milledby a laboratory procedure (“lab milled”) such as that specified in Practice B859. The values obtained are not intended to be absolutebut are generally useful on a relative basis for control purposes.1.2 Units
5、With the exception of the values for density and the mass used to determine density, for which the use of the gramper cubic centimetre (g/cm3) and gram (g) units is the longstanding industry practice; and the units for pressure, cm H2O - alsolong-standing practice; the values in SI units are to be r
6、egarded as standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to u
7、se.2. Referenced Documents2.1 ASTM Standards:2B243 Terminology of Powder MetallurgyB859 Practice for De-Agglomeration of Refractory Metal Powders and Their Compounds Prior to Particle Size AnalysisE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE456
8、 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 ISO/DIS Document:3ISO/DIS 10070 Metallic Powders: Determinations of Envelope-Specific Surface Area from Measurements of the Permeabilityto Air of a Powd
9、er Bed Under Steady-State Flow Conditions3. Terminology3.1 Definitions Many terms used in this test method are defined in Terminology B243.3.2 Definitions of Terms Specific to This Standard:3.2.1 HEL Sub-sieve AutoSizer (HEL SAS), na commercially available permeability instrument for measuring envel
10、opespe-cific surface area and estimating average particle size from 0.2 to 75m.3.2.2 Fisher sub-sieve sizer, Sub-Sieve Sizer (FSSS), na commercially available permeability instrument for measuringenvelope-specific surface area.area and estimating average particle size (Fisher Number) from 0.5 to 50
11、m.3.2.3 envelope-specific surface area, n specific surface area of a powder as determined by gas permeametry in accordancewith ISO/DIS 10070.1 ThisThese test method ismethods are under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Productsand isare the direct responsibilit
12、yof Subcommittee B09.03 on Refractory Metal Powders.Current edition approved March 15, 2007November 1, 2012. Published April 2007November 2012. Originally approved in 1958. Last previous edition approved in20052007 as B330 05.B330 07. DOI: 10.1520/B0330-07.10.1520/B0330-12.2 For referenced ASTM stan
13、dards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th F
14、loor, New York, NY 10036, http:/www.ansi.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately,
15、 ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive,
16、 PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.4 air permeability, nmeasurement of air pressure drop across a packed bed of powder.3.2.5 de-agglomeration, nprocess used to break up agglomerates of particles.3.2.6 Fisher Number, ncalculated value equated to an average particle diam
17、eter, assuming all the particles are spherical andof uniform size.3.2.7 Fisher calibrator tube, njewel with a precision orifice mounted in a tube similar to a sample tube. The calibrator tubevalue is directly traceable to the master tube maintained by Fisher. ASTM International Subcommittee B09.03 o
18、n Refractory MetalPowders3.2.8 porosity of a bed of powder, nratio of the volume of the void space in the powder bed to the that of the overall volumeof the powder bed.3.2.9 agglomerate, nseveral particles adhering together.3.2.10 average particle size, n(for the purposes of these test methods only)
19、 an estimate of the equivalent average sphericalparticle diameter, calculated from the measured envelope-specific surface area, assuming that all the powder particles are sphericaland that all are exactly the same size.4. Significance and Use4.1 This test method provides a procedure These test metho
20、ds provide procedures for determining the envelope-specific surfacearea of powders, from which is calculated an “average” particle diameter, assuming the particles are monosize, smooth surface,nonporous, spherical particles. For this reason, values obtained by thisthese test methodmethods will be de
21、fined as a reported asan average particle size or Fisher Number. The degree of correlation between the results of thisthese test methodmethods and thequality of powders in use will vary with each particular application and has not been fully determined.4.2 ThisThese test method ismethods are general
22、ly applicable to all metal powders and related compounds, including carbides,nitrides, and oxides, for particles having diameters between 0.2 and 75 m (HEL SAS) or between 0.5 and 50 m. It m (FSSS).They should not be used for powders composed of particles whose shape is too far from equiaxed, equiax
23、ed - that is, flakes orfibers. In these cases, it is permissible to use the test methodmethods described only by agreement between the parties concerned.ThisThese test methodmethods shall not be used for mixtures of different powders, nor for powders containing binders orlubricants. When the powder
24、contains agglomerates, the measured surface area may be affected by the degree of agglomeration.Methods of de-agglomeration such as that referencedspecified in 1.1Practice B859 may be used if agreed upon between the partiesconcerned.4.3 When an “average” particle size of powders is determined using
25、the Fisher sub-sieve sizer, either the HEL SAS or the FSSS,it should be clearly kept in mind that this average size is derived from the determination of the specific surface area of the powderusing a relationship that is true only for powders of uniform size and spherical shape. Thus, the results of
26、 these methods are onlyestimates of average particle size.5. Apparatus5.1 HEL Sub-sieve AutoSizer (HEL SAS)4 Method 1The Fisher sub-sieve sizer consisting consists of an air pump, anair-pressure regulating device, a a calibrated gas mass flow controller, a precision-bore sample tube, a standardized
27、double-rangeair flowmeter, and a calculator chart. sample tube retaining collar, a spacer tool, a gas flow metering valve, two precision pressuretransducers (inlet and outlet), a stepper motor controlled ballscrew-mounted piston, and computer hardware and software forinstrument control and calculati
28、on and reporting of results. Included is accessory equipment consisting of a plug manipulator,powder funnel,manipulator (extraction rod), two porous plugs, and a supply of paper disks, and a rubber tube support stand.disks.NOTE 1Necessary replacement parts should be obtained from the manufacturer, e
29、specially in the case of the precision manometer which is a part ofthe air flowmeter.When homing the piston, adjust the sample packing assembly (1) as described in the manufacturers directions, with the plugs and paperdisks stacked together and placed on the fixed anvil spigot, or (2) using a specia
30、lly designed baseline (homing) gauge instead of the plugs and paper disks.This baseline gauge shall have a height of 20.30 6 0.10 mm. Check all plug heights when new plugs are purchased and periodically thereafter to makesure all are equal in height.5.1.1 Powder funnelstainless steel, with spout out
31、side diameter slightly smaller than the sample tube inside diameter.5.1.2 The manufacturer provides instructions which should be followed, using the “Inorganics Test” procedure when testingmetal powders and related compounds. Particular attention should be given to proper maintenance of the instrume
32、nt with special4 The sole source of supply of the Fisher sub-sieve sizer #14-311A HEL Sub-sieve AutoSizer (HEL SAS) known to the committee at this time is Fisher Scientific,Instrument Division, 2000 Park Lane, Pittsburgh, PA 15275. Besides supplying the basic instrument, they also supply accessories
33、 of: calibrator tube #14-313-7 and samplecalibrator, #14-311-2. is Hazard Evaluation Laboratory Limited, 9-10 Capital Business Park, Manor Way, Borehamwood, Hertfordshire, WD6 1GW. UK. The instrument isexclusively distributed globally by Micromeritics Instrument Corporation, Particulate Systems, 435
34、6 Communications Drive, Norcross, GA 30093-2901, USA. If you areaware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1 which you may attend.B330 122refer
35、ence to the instructions on (1) “homing” the piston when turning on from an unpowered state, (2) setting the pressure andperiodic checking of the pressure, (3) condition of O-rings on the piston and sample spigot, and (4) the sample packing assembly(plugs and paper disks).5.2 The manufacturer also f
36、urnishes directions which should be followed except as amended as follows. Particular attentionshould be given to proper maintenance of the instrument with special reference to the instructions on (1) periodic checking of thewater level in the pressure regulator standpipe, (2) manometer level before
37、 the sample tube is inserted, and ( 3) the sample packingassembly.5.2 Jewel Calibrator TubeFisher Sub-Sieve Sizer (FSSS)5 Method 2a standard for average particle size measurement. Itallows operators to relate their data to that of other analysts. Each calibrator is factory tested three times with th
38、e resulting readingsand associated porosity recorded on the tube.consisting of an air pump, an air-pressure regulating device, a precision-bore sampletube, a standardized double-range air flowmeter, and a calculator chart. Included is accessory equipment consisting of a plugmanipulator, powder funne
39、l, two porous plugs, a supply of paper disks, and a rubber tube support stand.NOTE 2Adjust the sample packing assembly (Necessary replacement parts should be obtained1) as described in the manufacturers directions withthe exception that the plugs and paper disks are not inserted in the sample tube,
40、but are merely stacked together and placed between the brass supportand the “flat” of the bottom of the rack, and ( from the manufacturer, especially in the case of the precision manometer which 2) as previously describedexcept that a specially made baseline gauge is used instead of the plugs and pa
41、per disks. This baseline gauge shall have a height of 19.30 6 0.10 mm.Check all plug heights when new plugs are purchased and periodically thereafter to make sure all are equal in height. is a part of the air flowmeter.5.2.1 The manufacturer has also furnished instructions which should be followed e
42、xcept as amended as follows. Particularattention should be given to proper maintenance of the instrument with special reference to the instructions on (1) periodicchecking of the water level in the pressure regulator standpipe, (2) manometer level before the sample tube is inserted, and ( 3)the samp
43、le packing assembly.5.2.2 Jewel Calibrator Tube6a tube to be used as a standard for average particle size measurement. It allows operators torelate their data to that of other analysts. Each calibrator has been factory tested three times with the resulting readings andassociated porosity recorded on
44、 the tube.NOTE 3Adjust the sample packing assembly (1) as described in the manufacturers instructions with the exception that the plugs and paper disks arenot inserted in the sample tube, but are merely stacked together and placed between the brass support and the “flat” of the bottom of the rack, a
45、nd ( 2)as previously described except that a specially made baseline gauge is used instead of the plugs and paper disks. This baseline gauge shall have a heightof 19.30 6 0.10 mm. Check all plug heights when new plugs are purchased and periodically thereafter to make sure all are equal in height.5.3
46、 Balancehaving a capacity of at least 50 g and a sensitivity of 0.001 g.6. Standardization of Apparatus6.1 Before proceeding with standardization of the Fisher sub-sieve sizer, the following items shall be checked:Method 1 HELSub-sieve AutoSizer (HEL SAS):6.1.1 The chart shall be properly aligned ho
47、rizontally with the indicator pointer.6.1.2 The rack and pinion shall be properly aligned vertically with the chart.6.1.3 The sample tube or plugs shall not be worn.6.1.4 The manometer and air resistors shall be free of visible contamination.6.1.1 The rubber sample tube seals shall not be worn to th
48、e point where leakage occurs.Before proceeding with standardizationof the HEL SAS, the following items shall be checked:6.1.1.1 The sample tube and plugs shall not be worn to the point where results are affected.6.1.1.2 Inspect the O-ring seals for tears and abrasion marks. The O-ring seals shall no
49、t be worn to the point where the sampletube moves easily by hand or the pressure reading varies as the sample tube is moved.6.1.1.3 The drying agent shall be in proper condition.6.1.2 The sample packing post shall be properly adjusted. Whenever the instrument is turned on from an unpowered state, thepiston shall be “homed” according to the manufacturers instructions. See Note 1 above.6.1.7 The drying agent shall be in proper condition.6.1.3 The manometer and standpipe levels shall be checked. Before running the initial sample, the pressure
