1、Designation: E883 11Standard Guide forReflectedLight Photomicrography1This standard is issued under the fixed designation E883; 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 indi
2、cates 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 Defense.1. Scope*1.1 This guide outlines various methods which may befollowed in the photography of
3、metals and materials with thereflected-light microscope. Methods are included for prepara-tion of prints and transparencies in black-and-white and incolor, using both direct rapid and wet processes.1.2 Guidelines are suggested to yield photomicrographs oftypical subjects and, to the extent possible,
4、 of atypical subjectsas well. Information is included concerning techniques for theenhanced display of specific material features. Descriptivematerial is provided where necessary to clarify procedures.References are cited where detailed descriptions may behelpful.1.3 This standard does not purport t
5、o address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use. Specific precau-tionary statements are given in X
6、1.7.1.4 The sections appear in the following order:Referenced documents 2Terminology 3Significance and use 4Magnification 5Reproduction of photomicrographs 6Optical systems 7Illumination sources 8Illumination of specimens 9Focusing 10Filters for photomicrography 11Illumination techniques 12Instant-p
7、rocessing films 13Photographic materials 14Photographic exposure 15Photographic processing 16Keywords 17Suggestions for visual use of metallographic micro-scopesAppendixX1Guide for metallographic photomacrography AppendixX2Electronic photography AppendixX32. Referenced Documents2.1 ASTM Standards:2E
8、7 Terminology Relating to MetallographyE175 Terminology of MicroscopyE768 Guide for Preparing and Evaluating Specimens forAutomatic Inclusion Assessment of SteelE1951 Guide for Calibrating Reticles and Light MicroscopeMagnifications2.2 Other Standard:3MSDS Mercury-Material Safety Data Sheet3. Termin
9、ology3.1 DefinitionsFor definitions of terms used in this guide,see Terminologies E7 and E175.4. Significance and Use4.1 This guide is useful for the photomicrography andphotomacrography of metals and other materials.4.2 The subsequent processing of the photographic materi-als is also treated.5. Mag
10、nification5.1 Photomicrographs shall be made at preferred magnifi-cations, except in those special cases where details of themicrostructure are best revealed by unique magnifications.5.2 The preferred magnifications for photomicrographs, are:253,503,753, 1003, 2003, 2503, 4003, 5003, 7503,8003, and
11、10003.5.3 Magnifications are normally calibrated using a stagemicrometer. Calibration procedures in Guide E1951 should befollowed.6. Reproduction of Photomicrographs6.1 Photomicrographs should be at one of the preferredmagnifications. A milli- or micrometre marker shall be super-imposed on the photo
12、micrograph to indicate magnification, in1This guide is under the jurisdiction ofASTM Committee E04 on Metallographyand is the direct responsibility of Subcommittee E04.03 on Light Microscopy.Current edition approved May 1, 2011. Published May 2011. Originallyapproved in 1982. Last previous edition a
13、pproved in 2007 as E883 02(2007). DOI:10.1520/E0883-11.2For 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.3Avail
14、able from United States Environmental Protection Agency (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20004, http:/www.epa.gov.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
15、PA 19428-2959, United States.a contrasting tone. The published magnification, if known,should be stated in the caption.6.2 Photomicrograph captions should include basic back-ground information (for example, material identification,etchant, mechanical or thermal treatment details) and shouldbriefly d
16、escribe what is illustrated so that the photomicrographcan stand independent of the text.6.3 Arrows or other markings, in a contrasting tone, shall beused to designate specific features in a photomicrograph. Anymarking used shall be referenced in the caption.7. Optical Systems7.1 Microscope objectiv
17、es are available in increasing orderof correction as achromats, semiapochromats (fluorites) andapochromats (see Terminologies E7 and E175). Plan objectivesare recommended for photographic purposes because theircorrection provides a flatter image. The objective lens forms animage of the specimen in a
18、 specific plane behind the objectivecalled the back focal plane. (This is one of several possible realimage planes, called intermediary planes, where reticles maybe inserted as optical overlays on the image.)7.2 The eyepiece magnifies the back focal plane (or other)intermediary image for observation
19、 or photomicrography. Eye-pieces are sometimes also used to accomplish the full correc-tion of the objectives spherical aberration and to improve theflatness of field.7.2.1 The pupil of the observers eye must be brought tocoincidence with the eyepoint of the visual eyepiece to viewthe entire microsc
20、opical image. High-eyepoint eyepieces arenecessary for eyeglass users to see the entire image field.7.2.2 Most microscopes have built-in photographic capa-bilities that use an alternate image path through the microscopeleading to a camera attachment port or to a viewscreen. Aprojection eyepiece deli
21、vers the image to the camera port orscreen.7.3 Intermediate lenses (relay or tube lenses) are oftenrequired to transfer the specimen image from the intermediaryplane of the objective to that of the eyepiece. They may alsoadd their own magnification factor, either fixed or as a zoomsystem.7.4 The obj
22、ective, the eyepiece, and the compound micro-scope (including any intermediate lenses) are designed as asingle optical unit. It is recommended to use only objectivesand eyepieces which are intended for the microscope in use.7.5 The resolution of the microscope depends primarily onthe numerical apert
23、ure of the objective in use (1)4. The termempty magnification is used to describe high magnifications(above approximately 1100 times the numerical aperture of anobjective), which have been shown to offer no increase inimage resolution. Nevertheless, some types of information,such as the distance bet
24、ween two constituents, may be moreeasily obtained from microstructures examined at moderateempty magnifications.8. Illumination Sources8.1 Metallographic photomicrography typically uses Khlerillumination. To obtain Khler illumination, an image of thefield diaphragm is focused in the specimen plane,
25、and an imageof the lamp filament or arc is focused in the plane of theaperture diaphragm. Specific steps to obtain Khler illumina-tion vary with the microscope used. The manufacturersinstructions should be followed closely.8.2 For incandescent lamps, the applied voltage determinesthe unit brightness
26、 and the color temperature of the source.Evaporated tungsten blackens the envelope, resulting in dimin-ished brightness and color temperature as the lamp ages.Tungsten-halogen lamps minimize envelope blackening, main-taining constant brightness and color temperature for most oftheir life. The high b
27、rightness and 3200 K color temperature ofthese lamps makes them especially suitable for color photomi-crography.8.3 With arc sources, brightness per unit area is substan-tially higher than that from any incandescent source. Theirspectral output contains high energy spikes superimposed on awhite-ligh
28、t continuum. They also contain significant ultraviolet(UV) and infrared (IR) emissions that should be removed foreye safety (and for photographic consistency, with UV); see8.4, 11.3.1, and 11.5.2.8.3.1 Xenon arcs produce a spectral quality close to daylight(5600K), with a strong spike at 462 nm. Str
29、ong emissions inthe IR should be removed. Xenon arcs that do not produceozone are recommended.8.3.2 Carbon arcs have a continuous output in the visibleportion of the spectrum, with a color temperature near 3800Kand a strong emission line at 386 nm.8.3.3 Mercury arcs have strong UV and near-UV output
30、,and are particularly useful to obtain maximum resolution witha blue filter. The color quality is deficient in red; it cannot bebalanced for color photomicrography. WarningMercury hasbeen designated by EPA and many state agencies as a hazard-ous material that can cause central nervous system, kidney
31、, andliver damage. Mercury, or its vapor, may be hazardous tohealth and corrosive to materials. Caution should be takenwhen handling mercury and mercury-containing products. Seethe applicable product Material Safety Data Sheet (MSDS) fordetails and EPAs website (http:/www.epa.gov/mercury/faq.htm) fo
32、r additional information. Users should be aware thatselling mercury or mercury-containing products, or both, inyour state may be prohibited by state law.8.3.4 Zirconium arcs have strong spectral output lines in thenear IR, requiring filtration. Within the visible region, they arerated at 3200K color
33、 temperature.8.4 Arc lamps require heat protection for filters and otheroptical components, and certainly for eye safety. Infraredremoval may be obtained by: “hot” mirrors in the illuminationbeam to reflect IR while transmitting visible light; heat-absorbing filters to transmit visible light while a
34、bsorbing IR,for example, solid glass filters or liquid-filled cells.8.5 A detailed discussion of illumination sources and thequality of illuminants is given by Loveland (2).8.6 Some advice on using metallographic microscopes forvisual observation has been compiled in Appendix X1.4The boldface number
35、s in parentheses refer to the list of references at the end ofthis standard.E883 1129. Illumination of Specimens9.1 Photomicrographs are made with a compound micro-scope comprised at least of an objective lens and an eyepiecewith a vertical illuminator between them. Field and aperturediaphragms, wit
36、h a lamp and lamp condenser lenses, areintegral parts of the system. The microscope should allowsufficient adjustment to illuminate the field of view evenly andto completely fill the back aperture of the objective lens withlight.9.2 The vertical illuminator is a thin-film-coated plane glassreflector
37、 set at 45 to the optical axis behind the objective. Itreflects the illumination beam into the objective and transmitsthe image beam from the objective to the eyepiece. In somemicroscopes prism systems are used to perform this function.9.3 The field diaphragm is an adjustable aperture whichrestricts
38、 the illuminated area of the specimen to that which is tobe photographed. It eliminates contrast-reducing stray light.The field diaphragm is also a useful target when focusing alow-contrast specimen.9.4 The aperture diaphragm establishes the optimum bal-ance between contrast, resolution, and depth o
39、f field. It shouldbe set to illuminate about 70 % of the objectives aperturediameter. This can be observed by removing the eyepiece andinspecting the back of the objective, either directly or with apinhole eyepiece. The aperture diaphragm should never beused as a light intensity control.9.5 See Fig.
40、 1 for an illustration of a typical verticalillumination system.10. Focusing10.1 Sharp focus is necessary to obtain good photomicro-graphs.10.2 There are two systems for obtaining sharp focus:ground-glass focusing and aerial image focusing.10.2.1 For ground-glass focusing, relatively glare-free sur-
41、roundings and a magnifier up to about 33 are required. Tofocus, the focusing knob is oscillated between underfocus andoverfocus in succeedingly smaller increments until the image issharp.10.2.2 There are four possible variations for focusing anaerial image.10.2.2.1 The simplest case is a transparent
42、 spot on aground-glass containing a fiduciary mark in the film plane. Thespecimen image is focused to coincide with the fiduciary mark,using a magnifying loupe of about 33 to 53. When the focusis correct, the specimen image and the fiduciary mark will notmove with respect to each other when the oper
43、ators head ismoved.10.2.2.2 Asecond case uses a reticle fixed within the opticalsystem at an intermediary plane. Focusing is a two-stepprocess: focus the eyepiece on the reticle; bring the image intofocus against the reticle figure.10.2.2.3 In the third case, a reticle is inserted into a focusingeye
44、piece. Depending on equipment used, this can be either atwo or three-step process: focus the reticle within the eyepiece;next, set the proper interpupiliary distance, if required (someequipment requires a specific interpupiliary distance for eye-piece focus to coincide with camera focus); then focus
45、 theimage coincident with the reticle.10.2.2.4 The fourth case uses a single-lens reflex camerabody, where the camera focusing screen is the plane ofreference. An eyepiece magnifier for the camera is an impor-tant accessory for this case. An aerial image focusing screen ispreferred.10.3 The critical
46、 focus point is affected by both the principalillumination wavelength in use and the size of the aperturediaphragm. Final focusing should be checked with all filters,apertures, and other components set for the photomicrograph.11. Filters for Photomicrography11.1 Photomicrographs require filtration o
47、f the light source.This section describes filter types and their uses.11.2 Each filter selectively removes some wavelengths fromthe transmitted beam of light. Two types of filters, interferenceand absorption, can be used for this purpose.11.2.1 Interference filters act as selective mirrors. By means
48、of coatings on a glass substrate, they selectively transmitcertain wavelengths while reflecting all others. These filtersFIG. 1 Vertical Illuminating System for a Metallurgical MicroscopeE883 113may be used in high-energy light beams. The mirrored side ofthe filter should face the light source. (The
49、 hot mirrors in 8.4are interference filters.)11.2.2 Absorption filters are dyed substrates of glass, plas-tic, or gelatine. They absorb some wavelengths of light andtransmit the balance. Through their absorption, they canbecome overheated and damaged if placed in high-energy lightbeams without protection. The usual protection is either aninterference filter or a liquid-filled cell placed in the beambefore the absorption filter. Wratten gelatine filters are usedbelow as examples (3). Many similar glass and plastic filtersare also available.11.3 Certain general purpos
