1、Designation: B243 11Standard Terminology ofPowder Metallurgy1This standard is issued under the fixed designation B243; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the
2、 year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This terminology standard includes definitions that arehelpful in the interpretation and application of powder metal-lurgy terms.2. Referenced Documents2.1 ASTM Standards
3、:B331 Test Method for Compressibility of Metal Powders inUniaxial Compaction3. Terminology3.1 PowderTerms associated with production, character-ization, use, and testing of metal powders.3.1.1 Table of Contents1. Powders:1.0 General, 3.1.21.1 Processes to Produce Powder, 3.1.31.2 Types of Powder, 3.
4、1.41.3 Shapes of Powder Particles, 3.1.51.4 Additives to Powder, 3.1.61.5 Treatment of Powder, 3.1.71.6 Properties of Powder, 3.1.81.7 Procedures to Evaluate Powder, 3.1.91.8 Equipment to Evaluate Powder, 3.1.102. Forming:2.0 General, 3.2.12.1 Processes for Compacting, 3.2.22.2 Conditions of Compact
5、ing,2.3 Tools Used for Compacting, 3.2.32.4 Phenomena Resulting from Compaction, 3.2.42.5 Properties of Compacts, 3.2.62.6 Forging, 3.2.72.7 Metal Injection Molding, 3.2.83. Sintering:3.1 Process for Sintering, 3.3.13.2 Conditions During Sintering, 3.3.23.3 Phenomena Resulting from Sintering, 3.3.33
6、.4 Properties of Sintered Parts, 3.3.43.5 Procedure to Evaluate Sintered Parts, 3.3.53.6 Removal of Binders, 3.3.64. Postsinter Treatments:4.1 Processes, 3.4.15. Miscellaneous:5.1 Definitions, 3.5.15.2 Processes, 3.5.25.3 Materials, 3.5.33.1.2 General:agglomerate, nseveral particles adhering togethe
7、r.metal powder, nparticles of elemental metals or alloys,normally less than 1000 m (1 mm) in size.particulate matter, nsee powder.PM, nthe acronym for powder metallurgy.powder, nparticles that are usually less than 1000 m (1mm) in size.powder metallurgy, nthe production and utilization ofmetal powde
8、rs.3.1.3 Processes to Produce Powder:air classification, nthe separation of powder into particlesize fractions by means of an air stream of controlled velocity.atomization, nthe dispersion of a molten metal intoparticles by a rapidly moving gas or liquid stream or bymechanical means.chemical deposit
9、ion, nthe precipitation of one metal froma solution of its salts by the addition of another metal or reagentto the solution.chemically precipitated metal powder, npowder producedby the reduction of a metal from a solution of its salts either bythe addition of another metal higher in the electromotiv
10、e seriesor by other reducing agent.1This terminology is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and is the direct responsibility of Subcom-mittee B09.01 on Nomenclature and Technical Data.Current edition approved Nov. 15, 2011. Published December 2011.
11、Originallyapproved in 1949. Last previous edition approved in 2010 as B243 10. DOI:10.1520/B0243-11.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.classification, nseparation of a powder into fractionsaccording to particle size.disi
12、ntegration, nthe reduction of massive material topowder.gas classification, nthe separation of powder into particlesize fractions by means of a gas stream of controlled velocity.granulation, nthe production of coarse metal particles bypouring the molten metal through a screen into water (shotting)or
13、 by violent agitation of the molten metal while solidifying.milling, nthe mechanical treatment of metal powder, ormetal powder mixtures, as in a ball mill, to alter the size orshape of the individual particles or to coat one component ofthe mixture with another.pulverization, nthe reduction in parti
14、cle size of metalpowder by mechanical means, a specific type of disintegration.reduced metal powder, nmetal powder produced, withoutmelting, by the chemical reduction of metal oxides or othercompounds.3.1.4 Types of Powder:atomized metal powder, nmetal powder produced by thedispersion of a molten me
15、tal by a rapidly moving gas, or liquidstream, or by mechanical dispersion.carbonyl powder, na metal powder prepared by the ther-mal decomposition of a metal minuted powder, na powder produced by mechanicalattrition of solid metal or pletely alloyed powder, nsee pre-alloyed posite powder, na powder i
16、n which each particleconsists of two or more distinct constituents.dendritic powder, nparticles, usually of electrolytic origin,having the typical pine tree structure.diffusion-alloyed powder, na partially alloyed powderproduced by means of a diffusion anneal.electrolytic powder, npowder produced by
17、 electrolyticdeposition or by the pulverization of an electrodeposit.hybrid-alloy powder, na pre-alloyed or diffusion-alloyedpowder to which either elemental or master-alloy metal pow-ders have been admixed.hydrogen-reduced powder, npowder produced by the re-duction of a metal oxide in an atmosphere
18、 containing hydro-gen.master-alloy powder, na powder with high alloy concen-tration, designed to be diluted when mixed with a base powderto produce the desired composition.matrix metal, nthe continuous phase of a polyphase alloyor mechanical mixture; the physically continuous metallicconstituent in
19、which separate particles of another constituentare embedded.mechanically alloyed powder, na composite powder pro-duced by mechanically incorporating other constituents whichare generally insoluble within the deformable particles of thematrix metal.mixed powder, nsee powder mixture.nanopowder, na pow
20、der consisting of particles typicallyless than 100 nm in size.partially alloyed powder, na powder in which the alloyaddition or additions are metallurgically bonded to an elemen-tal or pre-alloyed powder.powder mixture, na powder made by mixing two or morepowders of differing chemical composition, p
21、article size dis-tribution, particle shape, or a combination of these character-istics.pre-alloyed powder, npowder composed of two or moreelements that are alloyed in the powder manufacturing processin which the particles are of the same nominal compositionthroughout. Synonymous with completely allo
22、yed powder.premix, na uniform mixture of ingredients to a prescribedanalysis, prepared by the powder producer, for direct use incompacting powder metallurgy products.sponge iron, na coherent, porous mass of substantiallypure iron produced by solid-state reduction of iron oxide (forexample, iron ore
23、or mill scale).sponge iron powder, nground and sized sponge iron,which may have been purified or annealed or both.sponge metal; nany porous metal produced by the reduc-tion or decomposition of a compound at temperature below themelting point of the metalsponge metal powder; na powder produced from a
24、 spongemetal by mechanical methods of size reduction.3.1.5 Shapes of Powder Particles:acicular powder, nneedle-shaped particles.flake powder, nflat or scale-like particles whose thicknessis small compared with the other dimensions.granular powder, nparticles having approximately equidi-mensional non
25、spherical shapes.irregular powder, nparticles lacking symmetry.needles, nelongated rod-like particles.nodular powder, nirregular particles having knotted,rounded, or similar shapes.platelet powder, na powder composed of flat particleshaving considerable thickness (as compared with flake pow-der).sph
26、erical powder, nglobular-shaped particles.3.1.6 Additives to Powder:binder, na cementing medium; either a material added tothe powder to increase the green strength of the compact, andwhich is expelled during sintering; or a material (usually ofrelatively lower melting point) added to a powder mixtu
27、re forthe specific purpose of cementing together powder particleswhich alone would not sinter into a strong body.dispersion-strengthened material, na material consistingof a metal and finely dispersed, substantially insoluble, metallicor nonmetallic phase.feedstock, nin metal injection molding (MIM)
28、, a moldablemixture of metal powder and binder.lubricantmaterial used to reduce inter-particle friction andthe friction between the powder mass and the tooling.lubricant (admixed), na lubricant incorporated into apowder mixture.lubricant (die-wall), na lubricant applied to the toolingsurfaces to fac
29、ilitate ease of movement of the tooling and theremoval of the compact or part from the tooling.pore-forming material, na substance included in a powdermixture that volatilizes during sintering and thereby producesB243 112a desired kind and degree of porosity in the finished compact.3.1.7 Treatment o
30、f Powder:blending, nthe thorough intermingling of powders of thesame nominal composition (not to be confused with mixing).cross-product contamination, nthe unintentional mixingof powders with distinct differences in either physical charac-teristics or chemical composition or both.equalizing, nsee bl
31、ending.mixing, nthe thorough intermingling of powders of two ormore materials.3.1.8 Properties of Powder:angle of repose, nthe basal angle of a pile formed bypowder when freely poured under specified conditions onto ahorizontal surface.apparent density, nthe mass of a unit volume of powder,usually e
32、xpressed as grams per cubic centimetre, determinedby a specified method.bulk density, nthe mass per unit volume of a powder undernonstandard conditions, for example, in a shipping container(not to be confused with apparent density).compactibility, na conceptual term, encompassing thepowder character
33、istics of compressibility, green strength, edgeretention, and lamination tendency, that relates to the ability ofa powder to be consolidated into a usable green pressibility, nthe capacity of a metal powder to bedensified under a uniaxially applied pressure in a closed die.DISCUSSIONCompressibility
34、is measured in accordance with TestMethod B331 and may be expressed numerically as the pressure toreach a specified density, or alternatively the density at a givenpressure.2compression ratio, nthe ratio of the volume of the loosepowder to the volume of the compact made from it. Synony-mous with fil
35、l ratio.cut, nsee fraction.fill ratio, nsee compression ratio.fines, nthe portion of a powder composed of particleswhich are smaller than a specified size, currently less than 44m. See also superfines.flow rate, nthe time required for a powder sample ofstandard weight to flow through an orifice in a
36、 standardinstrument according to a specified procedure.fraction, nthe portion of a powder sample that liesbetween two stated particle sizes. Synonymous with cut.green density, nthe mass per unit volume of an unsinteredPM part or test specimen.hydrogen loss, nthe loss in weight of metal powder or ofa
37、 compact caused by heating a representative sample for aspecified time and temperature in a purified hydrogenatmospherebroadly, a measure of the oxygen content of thesample when applied to materials containing only such oxidesas are reducible with hydrogen and no hydride-forming ele-ment.impregnated
38、 density, nthe mass per unit volume of asintered PM part or test specimen, impregnated with oil orother lubricants. Synonymous with density (wet).minus sieve, nthe portion of a powder sample whichpasses through a standard sieve of specified number. (See plussieve.)oversize powder, nparticles coarser
39、 than the maximumpermitted by a given particle size specification.particle size, nthe controlling lineal dimension of anindividual particle as determined by analysis with sieves orother suitable means.particle size distribution, nthe percentage by weight, or bynumber, of each fraction into which a p
40、owder sample has beenclassified with respect to sieve number or microns. (Preferredusage: “particle size distribution by frequency.”)plus sieve, nthe portion of a powder sample retained on astandard sieve of specified number. (See minus sieve.)segregation, nthe separation of one or more constituents
41、of a powder, for example, by particle size or chemicalcomposition.sieve fraction, nthat portion of a powder sample thatpasses through a standard sieve of specified number and isretained by some finer sieve of specified number.sintered density, nthe mass per unit volume of a sinteredPM part or test s
42、pecimen not impregnated with oil or otherlubricant. Synonymous with density (dry).specific surface, nthe surface area of one gram of powder,usually expressed in square centimetres.subsieve fraction, nthe portion of powder passing througha 45-m (no. 325) sieve.superfines, nthe portion of a powder com
43、posed of particlesthat are smaller than a specified size, currently less than 10 m.tap density, nthe apparent density of the powder in acontainer that has been tapped under specified conditions.3.1.9 Procedures to Evaluate Powder:screen analysis, nsee sieve analysis.sieve analysis, nparticle size di
44、stribution; usually ex-pressed as the weight percentage retained upon each of a seriesof standard sieves of decreasing size and the percentage passedby the sieve of finest size. Synonymous with screen analysis.sieve classification, nthe separation of powder into par-ticle size ranges by the use of a
45、 series of graded sieves.3.1.10 Equipment to Evaluate Powder:powder flow meter, nan instrument for measuring the rateof flow of a powder according to a specified procedure.3.2 FormingTerms associated with consolidation of metalpowders and mixes, including tooling, equipment, and charac-terization of
46、 sintered compacts.3.2.1 General:blank, na pressed, presintered, or fully sintered compact,usually in the unfinished condition, requiring cutting, machin-ing, or some other operation to give it its final shape.briquet, nsee compact.2See Test Method B331.B243 113compact, nan object produced by the co
47、mpression ofmetal powder, generally while confined in a die, with orwithout the inclusion of nonmetallic constituents. Synonymouswith posite compact, na metal powder compact consistingof two or more adhering layers, rings, or other shapes ofdifferent metals or alloys with each material retaining its
48、original pound compact, na metal powder compact consistingof mixed metals, the particles of which are joined by pressingor sintering or both, with each metal particle retaining substan-tially its original composition.greenunsintered (not sintered); for example, green com-pact, green density, green s
49、trength.heating rate, nthe average temperature change per unittime between prescribed temperatures during the heating phaseof a thermal process.preformingthe initial pressing of a metal powder to form acompact that is subjected to a subsequent pressing operationother than coining or sizing.Also, the preliminary shaping of arefractory metal compact after presintering and before the finalsintering.pressed bar, na c
