ASTM B761-2017 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation《用重力沉降的X射线监测法测定金属粉末及其相关化合物的粒度分.pdf
《ASTM B761-2017 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation《用重力沉降的X射线监测法测定金属粉末及其相关化合物的粒度分.pdf》由会员分享,可在线阅读,更多相关《ASTM B761-2017 Standard Test Method for Particle Size Distribution of Metal Powders and Related Compounds by X-Ray Monitoring of Gravity Sedimentation《用重力沉降的X射线监测法测定金属粉末及其相关化合物的粒度分.pdf(4页珍藏版)》请在麦多课文档分享上搜索。
1、Designation: B761 17Standard Test Method forParticle Size Distribution of Metal Powders and RelatedCompounds by X-Ray Monitoring of Gravity Sedimentation1This standard is issued under the fixed designation B761; the number immediately following the designation indicates the year oforiginal adoption
2、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.1. Scope*1.1 This test method covers the determination of particlesize distributions of m
3、etal powders. Experience has shown thatthis test method is satisfactory for the analysis of elementaltungsten, tungsten carbide, molybdenum, and tantalumpowders, all with an as-supplied estimated average particle sizeof 6 m or less, as determined by Test Method B330. Othermetal powders (for example,
4、 elemental metals, carbides, andnitrides) may be analyzed using this test method with cautionas to significance until actual satisfactory experience is devel-oped (see 7.2). The procedure covers the determination ofparticle size distribution of the powder in the following twoconditions:1.1.1 As the
5、powder is supplied (as-supplied), and1.1.2 After the powder has been deagglomerated by rodmilling as described in Practice B859.1.2 This test method is applicable to particles of uniformdensity and composition having a particle size distributionrange of 0.1 up to 100 m.1.2.1 However, the relationshi
6、p between size and sedimen-tation velocity used in this test method assumes that particlessediment within the laminar flow regime. This requires that theparticles sediment with a Reynolds number of 0.3 or less.Particle size distribution analysis for particles settling with alarger Reynolds number ma
7、y be incorrect due to turbulent flow.Some materials covered by this test method may settle withReynolds number greater than 0.3 if particles greater than 25m are present. The user of this test method should calculatethe Reynolds number of the largest particle expected to bepresent in order to judge
8、the quality of obtained results.Reynolds number (Re) can be calculated using the flowingequationRe 5D3 2 0!0g182(1)whereD = the diameter of the largest particle expected to bepresent, = the particle density,0= the suspending liquid density,g = the acceleration due to gravity, and = is the suspending
9、 liquid viscosity.A table of the largest particles that can be analyzed withReynolds number of 0.3 or less in water at 35C is given for anumber of metals in Table 1.Acolumn of the Reynolds numbercalculated for a 30m particle sedimenting in the same liquidsystem is given for each material also.1.3 Un
10、itsWith the exception of the values for density andthe mass used to determine density, for which the use of thegram per cubic centimetre (g/cm3) and gram (g) units is thelongstanding industry practice, the values in SI units are to beregarded as standard.1.4 This standard does not purport to address
11、 all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard information is given in Sect
12、ion 7.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarri
13、ers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B330 Test Methods for Estimating Average Particle Size ofMetal Powders and Related Compounds Using Air Per-meabilityB821 Guide for Liquid Dispersion of Metal Powders andRelated Compounds for Particle Size Analysis1This test meth
14、od is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and is the direct responsibility of Subcom-mittee B09.03 on Refractory Metal Powders.Current edition approved Oct. 15, 2017. Published December 2017. Originallyapproved in 1986. Last previous edition approve
15、d in 2011 as B761 06(2011). DOI:10.1520/B0761-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary o
16、f Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in t
17、he Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1B859 Practice for De-Agglomeration of Refractory MetalPowders and Their Compounds Prior to Particle SizeAnalysisE456
18、 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Summary of Test Method3.1 A carefully dispersed homogeneous suspension of thepowder is permitted to settle in a cell scanned by a collimatedX-ray beam of
19、constant intensity. The net X-ray signal isinversely proportional to the sample concentration in thedispersing medium, and the particle diameter is related to theposition of the X-ray beam relative to the top of the cell.Cumulative mass percent versus equivalent spherical diameterare recorded to yie
20、ld a particle size distribution curve.4. Significance and Use4.1 This test method is useful to both producers andpurchasers of powders, as outlined in 1.1 and 1.2, in determin-ing particle size distribution for product specifications, manu-facturing control, development, and research.4.2 Users shoul
21、d be aware that sample concentrations usedin this test method may not be what is considered ideal by someauthorities, and that the range of this test method extends intothe region where Brownian movement could be a factor inconventional sedimentation. Within the range of this testmethod, neither the
22、 sample concentration nor Brownian move-ment are believed to be significant.4.3 Reported particle size measurement is a function of boththe actual particle dimension and shape factor as well as theparticular physical or chemical properties being measured.Caution is required when comparing data from
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