ASTM B243-2008 Standard Terminology of Powder Metallurgy.pdf

1、Designation: B 243 08Standard Terminology ofPowder Metallurgy1This standard is issued under the fixed designation B 243; 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 t

2、he 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 Standar

3、ds:B 331 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,

4、 3.1.41.3 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 Comp

5、acting, 3.2.32.3 Tools Used for Compacting, 3.2.42.4 Phenomena Resulting from Compaction, 3.2.52.5 Properties of Compacts, 3.2.72.6 Forging, 3.2.82.7 Metal Injection Molding, 3.2.93. Sintering:3.1 Process for Sintering, 3.3.13.2 Conditions During Sintering, 3.3.23.3 Phenomena Resulting from Sinterin

6、g, 3.3.33.4 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:1001 agglomerate, nseveral particles ad

7、hering together.1002 particulate matter, nsee powder.1003 P/M, nthe acronym representing powder metallurgy.Used as P/M Part, P/M Product, P/M Process, and so forth.1004 powder metallurgy, nthe production and utilizationof metal powders.1005 powder, nparticles that are usually less than 1000 m(1 mm)

8、in size.1006 metal powder, nparticles of elemental metals oralloys, normally less than 1000 m (1 mm) in size.3.1.3 Processes to Produce Powder:1101 atomization, nthe dispersion of a molten metal intoparticles by a rapidly moving gas or liquid stream or bymechanical means.1102 granulation, nthe produ

9、ction of coarse metal par-ticles by pouring the molten metal through a screen into water(shotting) or by violent agitation of the molten metal whilesolidifying.1103 classification, nseparation of a powder into fractionsaccording to particle size.1104 air classification, nthe separation of powder int

10、oparticle size fractions by means of an air stream of controlledvelocity.1105 gas classification, nthe separation of powder intoparticle size fractions by means of a gas stream of controlledvelocity.1This terminology is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Pr

11、oducts and is the direct responsibility of Subcom-mittee B09.01 on Nomenclature and Technical Data.Current edition approved Feb. 1, 2008. Published March 2008. Originallyapproved in 1949. Last previous edition approved in 2006 as B 243 06.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box

12、C700, West Conshohocken, PA 19428-2959, United States.1106 chemical deposition, nthe precipitation of one metalfrom a solution of its salts by the addition of another metal orreagent to the solution.1107 chemically precipitated metal powder, npowder pro-duced by the reduction of a metal from a solut

13、ion of its saltseither by the addition of another metal higher in the electro-motive series or by other reducing agent.1108 reduced metal powder, nmetal powder produced,without melting, by the chemical reduction of metal oxides orother compounds.1109 disintegration, nthe reduction of massive materia

14、l topowder.1110 milling, nthe mechanical treatment of metal powder,or metal 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.1111 pulverization, nthe reduction in particle size of metalpowder by mechanical m

15、eans, a specific type of disintegration.3.1.4 Types of Powder:1201 atomized metal powder, nmetal powder produced bythe dispersion of a molten metal by a rapidly moving gas, orliquid stream, or by mechanical dispersion.1202 electrolytic powder, npowder produced by electro-lytic deposition or by the p

16、ulverization of an electrodeposit.1203 dendritic powder, nparticles, usually of electrolyticorigin, having the typical pine tree structure.1204 carbonyl powder, na metal powder prepared by thethermal decomposition of a metal carbonyl.1205 master-alloy powder, na powder with high alloyconcentration,

17、designed to be diluted when mixed with a basepowder to produce the desired composition.1206 pre-alloyed powder, npowder composed of two ormore elements that are alloyed in the powder manufacturingprocess in which the particles are of the same nominalcomposition throughout. Synonymous with completely

18、 al-loyed powder.1207 completely alloyed powder, nsee pre-alloyed pow-der.1208 partially alloyed powder, na powder in which thealloy addition or additions are metallurgically bonded to anelemental or pre-alloyed powder.1209 diffusion-alloyed powder, na partially alloyed pow-der produced by means of

19、a diffusion anneal.1210 mechanically alloyed powder, na composite powderproduced by mechanically incorporating other constituentswhich are generally insoluble within the deformable particlesof the matrix metal.1211 matrix metal, nthe continuous phase of a polyphasealloy or mechanical mixture; the ph

20、ysically continuous metal-lic constituent in which separate particles of another constitu-ent are embedded.1212 composite powder, na powder in which each particleconsists of two or more distinct constituents.1213 spongy, na porous condition in metal powder par-ticles usually observed in reduced oxid

21、es.1214 sponge iron, na coherent, porous mass of substan-tially pure iron produced by solid-state reduction of iron oxide(for example, iron ore or mill scale).1215 sponge iron powder, nground and sized sponge iron,which may have been purified or annealed or both.1216 mixed powder, na powder made by

22、mixing two ormore powders as uniformly as possible. The constituentpowders will differ in chemical composition or in particle sizeor shape, or a combination thereof.1217 premix, na uniform mixture of ingredients to aprescribed analysis, prepared by the powder producer, fordirect use in compacting po

23、wder metallurgy products.1218 comminuted powder, na powder produced by me-chanical attrition of solid metal or powder.1219 nanopowder, na powder consisting of particlestypically less than 100 nm in size.1220 hydrogen-reduced powder, npowder produced by thereduction of a metal oxide in an atmosphere

24、containinghydrogen.3.1.5 Shapes of Powder Particles:1301 acicular powder, nneedle-shaped particles.1302 needles, nelongated rod-like particles.1303 granular powder, nparticles having approximatelyequidimensional nonspherical shapes.1304 nodular powder, nirregular particles having knotted,rounded, or

25、 similar shapes.1305 irregular powder, nparticles lacking symmetry.1306 spherical powder, nglobular-shaped particles.1307 flake powder, nflat or scale-like particles whosethickness is small compared with the other dimensions.1308 plates, nflat particles of metal powder having con-siderable thickness

26、.1309 platelet powder, na powder composed of flat par-ticles having considerable thickness (as compared with flakepowder).3.1.6 Additives to Powder:1401 binder, na cementing medium; either a materialadded to the powder to increase the green strength of thecompact, and which is expelled during sinter

27、ing; or a material(usually of relatively lower melting point) added to a powdermixture for the specific purpose of cementing together powderparticles which alone would not sinter into a strong body.1402 feedstock, nin metal injection molding (MIM),amoldable mixture of metal powder and binder.1404 di

28、spersion-strengthened material, na material con-sisting of a metal and finely dispersed, substantially insoluble,metallic or nonmetallic phase.1405 pore-forming material, na substance included in apowder mixture that volatilizes during sintering and therebyproduces a desired kind and degree of poros

29、ity in the finishedcompact.3.1.7 Treatment of Powder:1501 blending, nthe thorough intermingling of powders ofthe same nominal composition (not to be confused withmixing).B2430821502 equalizing, nsee blending.1503 mixing, nthe thorough intermingling of powders oftwo or more materials.1504 cross-produ

30、ct contamination, nthe unintentionalmixing of powders with distinct differences in either physicalcharacteristics or chemical composition or both.3.1.8 Properties of Powder:1601 apparent density, nthe mass of a unit volume ofpowder, usually expressed as grams per cubic centimetre,determined by a spe

31、cified method.1602 bulk density, nthe mass per unit volume of a powderunder nonstandard conditions, for example, in a shippingcontainer (not to be confused with apparent density).1603 tap density, nthe apparent density of the powder in acontainer that has been tapped under specified conditions.1604

32、flow rate, nthe time required for a powder sample ofstandard weight to flow through an orifice in a standardinstrument according to a specified procedure.1605 specific surface, nthe surface area of one gram ofpowder, usually expressed in square centimetres.1606 compactibility, na conceptual term, en

33、compassingthe powder characteristics of compressibility, green strength,edge retention, and lamination tendency, that relates to theability of a powder to be consolidated into a usable greencompact.1607 compressibility, nthe capacity of a metal powder tobe densified under a uniaxially applied pressu

34、re in a closed die.DISCUSSIONCompressibility is measured in accordance with TestMethod B 331 and may be expressed numerically as the pressure toreach a specified density, or alternatively the density at a givenpressure.21608 compression ratio, nthe ratio of the volume of theloose powder to the volum

35、e of the compact made from it.Synonymous with fill ratio.1609 fill ratio, nsee compression ratio.1610 oversize powder, nparticles coarser than the maxi-mum permitted by a given particle size specification.1611 plus sieve, nthe portion of a powder sample retainedon a standard sieve of specified numbe

36、r. (See minus sieve.)1612 minus sieve, nthe portion of a powder sample whichpasses through a standard sieve of specified number. (See plussieve.)1613 fines, nthe portion of a powder composed of particleswhich are smaller than a specified size, currently less than 44m. See also superfines.1614 superf

37、ines, nthe portion of a powder composed ofparticles that are smaller than a specified size, currently lessthan 10 m.1615 fraction, nthe portion of a powder sample that liesbetween two stated particle sizes. Synonymous with cut.1616 cut, nsee fraction.1617 subsieve fraction, nthe portion of powder pa

38、ssingthrough a 45-m (no. 325) sieve.1618 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.1619 particle size, nthe controlling lineal dimension of anindividual particle as determined by ana

39、lysis with sieves orother suitable means.1620 particle size distribution, nthe percentage by weight,or by number, of each fraction into which a powder sample hasbeen classified with respect to sieve number or microns.(Preferred usage: “particle size distribution by frequency.”)1621 hydrogen loss, nt

40、he loss in weight of metal powderor of a compact caused by heating a representative sample fora specified 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

41、 no hydride-forming ele-ment.1622 segregation, nthe separation of one or more constitu-ents of a powder, for example, by particle size or chemicalcomposition.1623 angle of repose, nthe basal angle of a pile formed bypowder when freely poured under specified conditions onto ahorizontal surface.3.1.9

42、Procedures to Evaluate Powder:1701 sieve analysis, nparticle size distribution; usuallyexpressed as the weight percentage retained upon each of aseries of standard sieves of decreasing size and the percentagepassed by the sieve of finest size. Synonymous with screenanalysis.1702 screen analysis, nse

43、e sieve analysis.1703 sieve classification, nthe separation of powder intoparticle size ranges by the use of a series of graded sieves.3.1.10 Equipment to Evaluate Powder:1801 powder flow meter, nan instrument for measuring therate of flow of a powder according to a specified procedure.3.2 FormingTe

44、rms associated with consolidation of metalpowders and mixes, including tooling, equipment, and charac-terization of sintered compacts.3.2.1 General:2001 greenunsintered (not sintered); for example, greencompact, green density, green strength.2002 preformingthe initial pressing of a metal powder tofo

45、rm a compact that is subjected to a subsequent pressingoperation other than coining or sizing. Also, the preliminaryshaping of a refractory metal compact after presintering andbefore the final sintering.2003 blank, na pressed, presintered, or fully sinteredcompact, usually in the unfinished conditio

46、n, requiring cutting,machining, or some other operation to give it its final shape.2004 briquet, nsee compact.2005 compact, nan object produced by the compression ofmetal powder, generally while confined in a die, with orwithout the inclusion of nonmetallic constituents. Synonymouswith briquet.2006

47、pressed bar, na compact in the form of a bar; a greencompact.2See Test Method B 331.B2430832007 rolled compact, na compact made by passing metalpowder continuously through a rolling mill so as to formrelatively long sheets of pressed material.2008 composite compact, na metal powder compact con-sisti

48、ng of two or more adhering layers, rings, or other shapes ofdifferent metals or alloys with each material retaining itsoriginal identity.2009 compound compact, na metal powder compactconsisting of mixed metals, the particles of which are joined bypressing or sintering or both, with each metal partic

49、le retainingsubstantially its original composition.3.2.2 Processes for Compacting:2101 molding, vsee compacting.2102 press, vto apply force to a mass of powder, generallywhile confined in a die or container, to form a compact.2103 double press-double sinter, nto repress and sinter apreviously presintered or sintered compact.DISCUSSIONUsed to describe a four-step manufacturing process.2104 single-action pressing, na method by which apowder is pressed in a stationary die between one m