ASTM E7-2003(2009) 5000 Standard Terminology Relating to Metallography《与金相学相关的标准术语》.pdf

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1、Designation: E7 03 (Reapproved 2009)Standard Terminology Relating toMetallography1This standard is issued under the fixed designation E7; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in parenthe

2、ses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This standard covers the definition of terms, acronyms,and symbols used in

3、 ASTM documents related to the field ofmetallography and metallographic testing. Terms that are onlyrelevant to a particular standard or that are adequately definedin a general dictionary are not defined in this terminologystandard.1.2 This standard includes terminology used in metallo-graphic areas

4、, such as, but not limited to: light microscopy,microindentation hardness testing, specimen preparation, x-rayand electron metallography, quantitative metallography, pho-tomicrography, and determination of grain size and inclusioncontent.1.3 This standard may be of use to individuals utilizingstanda

5、rds of Committee E04 as well as by those in need of ageneral reference source for terminology in the field ofmetallography.2. Referenced Documents2.1 ASTM Standards:2E14 Discontinued 1983; Recommended Practice for Ther-mal Analysis of Metals and Alloys3E45 Test Methods for Determining the Inclusion

6、Content ofSteelE80 Discontinued 1986; Recommended Practice forDilatometric Analysis of Metallic Materials; Replaced byE 2283E92 Test Method for Vickers Hardness of Metallic Materi-alsE112 Test Methods for Determining Average Grain SizeE1122 Practice for Obtaining JK Inclusion Ratings UsingAutomatic

7、Image Analysis33. Significance and Use3.1 Standards of Committee E-4 consist of test methods,practices, and guides developed to ensure proper and uniformtesting in the field of metallography. In order for one toproperly use and interpret these standards, the terminologyused in these standards must b

8、e understood.3.2 The terms used in the field of metallography haveprecise definitions. The terminology and its proper usage mustbe completely understood in order to adequately communicatein this field. In this respect, this standard is also a generalsource of terminology relating to the field of met

9、allographyfacilitating the transfer of information within the field.4. Terminologyabsorptionthe decrease in intensity which radiation under-goes during its passage through matter when the ratio oftransmitted or reflected luminous flux to incident is less than1.absorption coefficientspecific factor c

10、haracteristic of asubstance on which its absorption radiation depends. Therate of decrease of the natural logarithm of the intensity of aparallel beam per unit distance traversed in a substance. ForX-rays, the linear absorption coefficient is the natural loga-rithm of the ratio of the incident inten

11、sity of an X-ray beamincident on unit thickness of an absorbing material to theintensity of the beam transmitted. If Ieis the incident inten-sity of a beam of X-rays, Itthe transmitted intensity, and Xthe thickness of the absorbing material, then:It5 Ieexp2X! (1)Here is the linear absorption coeffic

12、ient. The mass absorptioncoefficient is given by /r where r is the density.absorption edgean abrupt change in absorption coefficientat a particular wavelength. The absorption coefficient isalways larger on the short wavelength side of the absorptionedge.absorption limitSee absorption edge.accelerati

13、ng potentiala relatively high voltage applied be-tween the cathode and anode of an electron gun to accelerateelectrons.1This terminology is under the jurisdiction of ASTM Committee E04 onMetallography and are the direct responsibility of Subcommittee E04.02 onTerminology.Current edition approved Oct

14、. 1, 2009. Published March 2010. Originallyapproved in 1926. Last previous edition approved 2003 as E7 03. DOI: 10.1520/E0007-03R09_WIP_#863251.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards v

15、olume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.achroma

16、ticliterally, color-free. A lens or prism is said to beachromatic when corrected for two colors. The remainingcolor seen in an image formed by such a lens is said to besecondary chromatic aberration. See apochromatic objec-tiveachromatic objectivean objective that is corrected chro-matically for two

17、 colors, and spherically for one, usually inthe yellow-green part of the spectrum.achromatic objective lensan objective lens with longitudi-nal chromatic correction for green and blue, and sphericalchromatic correction for green. NoteLens should be usedwith a green filter.acid extractionSee extracti

18、on.air-lockan intermediate enclosed chamber of a vacuum orpressure system through which an object may be passedwithout materially changing the vacuum or pressure of thesystem.alignmenta mechanical or electrical adjustment of thecomponents of an optical device in such a way that the pathof the radiat

19、ing beam coincides with the optical axis or otherpredetermined path in the system. In electron optics there arethree general types:(1) magnetic alignmentan alignment of the electronoptical axis of the electron microscope such that the imagerotates about a point in the center of the viewing screen wh

20、enthe current flowing through a lens is varied.(2) mechanical alignmenta method of aligning thegeometrical axis of the electron microscope by relativephysical movement of the components, usually as a steppreceding either magnetic or voltage alignment.(3) voltage alignmenta condition of alignment of

21、anelectron microscope such that the image expands or con-tracts symmetrically about the center of the viewing screenwhen the accelerating voltage is changed.allotriomorphic crystala crystal whose lattice structure isnormal, but whose outward shape is imperfect since it isdetermined to some extent by

22、 the surroundings; the grains ina metallic aggregate are allotriomorphic crystals.alloy systema complete series of compositions produced bymixing in all proportions any group of two, or more,components, at least one of which is a metal.alpha brassa solid solution phase of one or more alloyingelement

23、s in copper and having the same crystal lattice ascopper.alpha iron (Fe)solid phase of pure iron which is stable attemperatures below 910C and possesses the body-centeredcubic lattice. It is ferro-magnetic below 768C.amplifiera negative lens, used in lieu of an eyepiece, toproject under magnificatio

24、n the image formed by an objec-tive. The amplifier is especially designed for flatness of fieldand should be used with an apochromatic objective.ampliphan eyepiece See amplifier.analyzeran optical device, capable of producing planepolarized light, used for detecting the state of polarization.angle o

25、f reflection: ( 1) reflectionthe angle between thereflected beam and the normal to the reflecting surface.(2) diffractionthe angle between the diffracted beam andthe diffracting planes.Angstrom unit (abbreviation) = A, , or A. Ua unit oflength equal to 108cm. This is the standard unit ofmeasurement

26、in X-ray crystallography.angular apertureSee aperture, optical.anisotropic (replaces anisotropy)having different values fora property, in different directions.annealing-twin bands See twin bands.anode apertureSee aperture.anvilthe base on which objects for hardness test are placed.anvil effectthe ef

27、fect caused by use of too high a load orwhen testing the hardness of too thin a specimen, resulting ina bulge or shiny spot on the under side of the specimen.aperture, electron:anode aperture the opening in the accelerating voltageanode shield of the electron gun through which the electronsmust pass

28、 to illuminate or irradiate the specimen.condenser aperturean opening in the condenser lenscontrolling the number of electrons entering the lens and theangular aperture of the illuminating beam. The angularaperture can also be controlled by the condenser lens current.physical objective aperturea met

29、al diaphragm, centrallypierced with a small hole, used to limit the cone of electronsaccepted by the objective lens. This improves image contrastsince highly scattered electrons are prevented from arrivingat the Gaussian image plane and therefore can not contributeto background fog.aperture, optical

30、the working diameter of a lens or a mirror.angular aperture the angle between the most divergentrays which can pass through a lens to form the image of anobject.aperture diaphragma device to define the aperture.apochromatic objectivean objective with longitudinal chro-matic correction for red, green

31、 and blue, and sphericalchromatic correction for green and blue. This is the bestchoice for high resolution or color photomicrography.arcingin electron diffraction, the production of segments ofcircular patterns, indicating a departure from completelyrandom orientation of the crystals of the specime

32、n.arrestthat portion of a cooling curve in which temperature isinvariant with time (for example, thermal or eutectic arrest).artifacta false microstructural feature that is not an actualcharacteristic of the specimen; it may be present as a resultof improper or inadequate preparation, handling metho

33、ds, oroptical conditions for viewing.ascending fork pointin a ternary phase diagram, the con-figuration at the convergence of the three bivariant curvesupon each of the four phases associated in Class II univariantequilibrium; for example, the union of two ascending liqui-dus surface valleys to form

34、 one ascending liquidus surfacevalley.aspect ratiothe length-to-width ratio of a microstructuralfeature in a two-dimensional plane.asterisma lengthening of diffraction spots usually in theradial direction.astigmatisma defect in a lens or optical system whichcauses rays in one plane parallel to the o

35、ptical axis to focusat a distance different from those in the plane at right anglesto it.E7 03 (2009)2ASTM grain size number See grain size.athermalnot isothermal, with changing rather than constanttemperature conditions.atomic replicaSee replica.atomic scattering factorthe ratio of the amplitude of

36、 thewave scattered by an atom to that scattered by a singleelectron. Symbol = f.austenitea face-centered cubic solid solution of carbon orother elements in gamma iron.austenite grain sizethe grain size which exists or existed inaustenite at a given temperature. See Test Methods E112.autographic dila

37、tometera dilatometer that automaticallyrecords instantaneous and continuous changes in dimensionsand some other controlled variable such as temperature ortime.autographic pyrometer See pyrometer.automatic image analysisthe separation and quantitativeevaluation of an image into its elements with or w

38、ithoutoperator interaction. It includes the enhancement, detection,and quantification of the features contained in an imagethrough the use of optical, geometrical, and stereologicalparameters and a computer program. Image analysis dataoutput can provide individual measurements on each sepa-rate feat

39、ure (feature specific) or totals for all features of aparticular type in the field (field specific).automatic image analyzera device which can be pro-grammed to detect and measure features of interest in animage. It may include accessories such as automatic focusand an automatic traversing stage to

40、permit unattendedoperation.average coefficient of cubical expansion average change inunit volume of a substance per unit change in temperatureover a specified range of temperature.average coefficient of linear expansion average change inunit length of a body per unit change in temperature over aspec

41、ified range of temperature.average coefficient of thermal expansion general term.(See also average coefficient of cubical expansion andaverage coefficient of linear expansion.)average grain diameter See grain size.axial ratiothe ratio of the length of one axis to that ofanother (for example, c/a) or

42、 the continued ratio of threeaxes (for example, a:b:c).axis (crystal)the edge of the unit cell of a space lattice. Anyone axis of any one lattice is defined, in length and direction,with respect to the other axes of that lattice.Babos lawthe vapor pressure over a liquid solvent islowered approximate

43、ly in proportion to the quantity of anonvolatile solute dissolved in the liquid.backing filma film used as auxiliary support for the thinreplica or specimen-supporting film.back reflectionthe diffraction of X-rays at a Bragg angleapproaching 90.background blackeninga continuous, slowly varyingblacke

44、ning of photographic film which has been exposed todiffracted X-rays, on which the blackening due to diffractedspots or lines is superimposed.bainiteupper, lower, intermediate metastable micro-structure or microstructures resulting from the transforma-tion of austenite at temperatures between those

45、whichproduce pearlite and martensite. These structures may beformed on continuous (slow) cooling if the transformationrate of austenite to pearlite is much slower than that ofaustenite to bainite. Ordinarily, these structures may beformed isothermally at temperatures within the above rangeby quenchi

46、ng austenite to a desired temperature and holdingfor a period of time necessary for transformation to occur. Ifthe transformation temperature is just below that at whichthe finest pearlite is formed, the bainite (upper bainite) has afeathery appearance. If the transformation temperature is justabove

47、 that at which martensite is produced, the bainite(lower bainite) is acicular, resembling slightly temperedmartensite. At the higher resolution of the electron micro-scope, upper bainite is observed to consist of plates ofcementite in a matrix of ferrite. These discontinuous carbideplates tend to ha

48、ve parallel orientation in the direction of thelonger dimension of the bainite areas. Lower bainite consistsof ferrite needles containing carbide platelets in parallelarray cross-striating each needle axis at an angle of about60. Intermediate bainite resembles upper bainite; however,the carbides are

49、 smaller and more randomly oriented.balanced filters (X-rays)a pair of filters used to eliminateall but a narrow range of wavelengths. The filter materialsand thicknesses are chosen so that their absorption edges lievery close together and so that they have the same absorptionexcept for wavelengths lying in the range between theirabsorption edges. When these filters are used alternately, thedifference in effect, if any, is due to X-rays that havewavelengths in this range. Balanced filters thus can be mad