1、Designation: E127 10Standard Practice forFabricating and Checking Aluminum Alloy UltrasonicStandard Reference Blocks1This standard is issued under the fixed designation E127; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 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.This specification has been approved for use by agencies of the Department of Defense.1. Scope1.1 This practice covers a proce
3、dure for fabricating alumi-num alloy ultrasonic standard reference blocks that can be usedfor checking performance of ultrasonic testing equipment andfor standardization and control of ultrasonic tests of aluminumalloy products using pulsed longitudinal waves introduced intotest material either by t
4、he direct-contact method or by theimmersion method. A recommended procedure for checkingblocks is described and calibration data for a number ofreference blocks are tabulated. Statements concerning proce-dures are provided without a discussion of the technicalbackground for the preference. The neces
5、sary technical back-ground can be found in Refs. (1-16).2NOTE 1Practice E428 and Guide E1158 also describe procedures forselecting material, fabricating blocks, and checking response. Unlike thispractice, there is no requirement for evaluation relative to a specifiedstandard target.1.2 This standard
6、 does not purport to 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 limitations prior to use.2. Referenced Documents2.1 ASTM
7、Standards:3E317 Practice for Evaluating Performance Characteristicsof Ultrasonic Pulse-Echo Testing Instruments and Systemswithout the Use of Electronic Measurement InstrumentsE428 Practice for Fabrication and Control of Metal, Otherthan Aluminum, Reference Blocks Used in UltrasonicTestingE1158 Guid
8、e for Material Selection and Fabrication ofReference Blocks for the Pulsed Longitudinal Wave Ultra-sonic Testing of Metal and Metal Alloy Production Mate-rialE1316 Terminology for Nondestructive ExaminationsE1324 Guide for Measuring Some Electronic Characteris-tics of Ultrasonic Examination Instrume
9、nts3. Terminology3.1 DefinitionsFor definitions of terms not specific to thispractice, refer to Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 angular errorthe condition observed in ultrasonictests of reference blocks when the response from the holebottom is not maximum w
10、hile the search unit is positioned toobtain either a maximum number of back reflections from areference block or a maximum indication from its entrysurface. Angular error results when the entry surface, holebottom, and back surface are not parallel to each other.3.2.2 area-amplitude response curvea
11、curve showing therelationship between different areas of reflecting targets locatedat a constant distance in an ultrasonic transmitting medium andtheir respective amplitudes of ultrasonic response.3.2.3 back reflectionthe indication, observed on the dis-play screen of a test instrument, that represe
12、nts the ultrasonicenergy reflected from the back surface of a reference block.3.2.4 back surfacethe end of a reference block that isopposite the entry surface.3.2.5 entry surfacethe end of a reference block throughwhich ultrasonic energy must pass when reflections from thehole bottom are obtained.3.
13、2.6 hole bottomthe flat reflecting surface in a referenceblock that is obtained by making the entire end of a drilled holesmooth and flat using best machining practices. The holebottom is parallel to the entry surface of the block.1This practice is under the jurisdiction of ASTM Committee E07 on Non
14、de-structive Testing and is the direct responsibility of Subcommittee E07.06 onUltrasonic Method.Current edition approved Feb. 15, 2010. Published March 2010. Originallyapproved in 1958. Last previous edition approved in 2007 as E127 - 07. DOI:10.1520/E0127-10.2The boldface numbers in parentheses re
15、fer to the list of references at the end ofthis practice.3For 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.1Cop
16、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.7 hole sizethe diameter of the hole in a referenceblock that determines the area of the hole bottom.3.2.8 metal distancethe distance in a reference block fromits entry surface to the ho
17、le bottom.3.2.9 reference blockan aluminum block, containing as anartificial discontinuity a flat-bottom drilled hole of known size.3.2.10 ultrasonic responsethe height of the indication,observed on a display screen of a test instrument, that repre-sents the amount of ultrasonic energy initially ref
18、lected fromthe hole bottom in a reference block. Units usually used inmeasuring height of indication are inches, trace-to-peak, orpercent of upper linearity limit.4. Summary of Practice4.1 Aluminum alloy stock is ultrasonically evaluated toensure freedom from significant discontinuities and is thenp
19、recisely fabricated into cylindrical blocks of prescribedlengths.Asingle, flat-bottom hole of specific diameter is drilledto a constant depth into the end of each block at its center, andthe blocks are grouped into sets according to hole size andblock length, or metal distance.4.2 Each block is chec
20、ked ultrasonically using a calibratedultrasonic test system at a prescribed test frequency. Distance-amplitude and area-amplitude characteristics are establishedfor sets of fabricated blocks using specific reflectors to providea standard response. Curves are plotted to establish theinterrelationship
21、 between the various blocks in the sets.4.3 To permit the use of instrumentation similar to thatoriginally used in developing this practice, or types morerecently manufactured, two alternative test system calibrationprocedures are described. The first method (ball-to-block)which utilizes steel balls
22、 as reference standards, is covered in11.8.2. The second method (block-to-block), which requires asreference standards, blocks which have been calibrated by theNational Institute of Standards and Technology (NIST), isdescribed in Annex A1.45. Significance and Use5.1 Reference blocks fabricated to th
23、is practice will exhibitspecific area-amplitude and distance-amplitude relationshipsonly with an immersion test at 5 MHz using the search unit,test instrument, and test parameters described in this practice.Comparison tests at other frequencies or with uncalibrated testsystems will not necessarily g
24、ive the same relationships shownin this practice.NOTE 2The 1964 and prior issues of this practice required a testfrequency of 15 MHz. Blocks conforming to earlier issues of this practicemay not produce ultrasonic responses that conform to this issue. SeeSection 13 regarding provision for recertifica
25、tion or correction curves andtables.5.2 Although the primary ultrasonic evaluation of blocks isperformed at a specified frequency, the blocks may be used tostandardize ultrasonic tests at any frequency and with anypulse-echo ultrasonic test system. Establishment of distance-amplitude and area-amplit
26、ude characteristics is necessary foreach application. This use may be inappropriate for othermaterials and curved surfaces without special compensation.Also see (3) for cautions regarding use of standard blocks fortest standardization.6. Description of Various Recommended Sets6.1 In ultrasonic testi
27、ng of aluminum alloy products, astandard reference usually is necessary to establish a specifiedtest sensitivity. A standard ultrasonic reference also is requiredfrequently to determine the effect of variations in metaldistance upon the ultrasonic response from detected disconti-nuities. Test sensit
28、ivity standardizations and corrections formetal distance are most reliable when made under the sameconditions employed for the actual tests. For these purposes,aluminum alloy reference blocks containing various combina-tions of hole size and metal distance are necessary.6.2 The following combination
29、s or sets of blocks are rec-ommended:6.2.1 Basic SetThe basic set consisting of ten referenceblocks is listed in Table 1. Area-amplitude relations areobtained by intercomparison of blocks containing the 3-in.(76.2-mm) metal distance and364-in.,564-in., and864- in. (seeNote 3) diameter holes, respect
30、ively. Distance-amplitude rela-tions are obtained by intercomparison of the blocks of variouslengths which contain564-in. diameter holes.NOTE 3Direct conversion from inches to millimetres (1 in. = 25.4mm) gives hole size dimensions for which there are no standard metricdrills; however, Table 2 gives
31、 the nearest standard metric drill size.6.2.2 Area-Amplitude SetThe area-amplitude set consist-ing of eight ultrasonic standard reference blocks is listed inTable 3. Area-amplitude relationships are obtained by inter-comparison of any three or more blocks with different flatbottom-hole sizes at the
32、same metal distance from front surfaceto hole bottom.6.2.3 Distance-Amplitude SetA distance-amplitude setmay include any convenient number of the reference blocksshown in Table 4 and does not necessarily include all blockslisted. A recommended distance-amplitude set contains at least12 blocks, and e
33、ach set contains only one of the three hole sizesshown in Table 4. Blocks comprising the 19 block distance-amplitude sets, which are customarily supplied commercially,4Measurement services to determine the ultrasonic response of reference blocksintended to meet the requirements of this practice are
34、available from severalcommercial testing laboratories.TABLE 1 Dimensions and Identification of Reference Blocks inthe Basic Set (see Fig. 1)BlockIdenti-ficationNumberHoleDiameter(A)MetalDistance(B)OverallLength(C)164 thsin.in. mm in. mm3-0300 3 3.000 76.2 3.750 95.25-0012 5 0.125 3.2 0.875 22.25-002
35、5 5 0.250 6.4 1.000 25.45-0050 5 0.500 12.7 1.250 31.85-0075 5 0.750 19.0 1.500 38.15-0150 5 1.500 38.1 2.250 57.25-0300 5 3.000 76.2 3.750 95.25-0600 5 6.000 152.4 6.750 171.48-0300 8 3.000 76.2 3.750 95.28-0600 8 6.000 152.4 6.750 171.4E127 102are indicated in Table 4. Increments of metal distance
36、 in eachof the three groups of blocks in the recommended set should beidentical. Distance-amplitude relationships are obtained byintercomparison of all blocks containing the same size hole.6.3 If the blocks are to be used for immersion testing, theyshould be suitably anodized or otherwise protected
37、to enhanceresistance to corrosion. Blocks with coated surfaces may beused with search units requiring external ground providedsuitable arrangements are made for adequate electrical contact.Uncoated blocks shall be designated as Type 1; coated blocksshall be designated as Type 2. The ultrasonic chara
38、cteristics ofboth types shall be checked by the immersion method asprescribed in Section 11. However, care must be exercised todry the Type 1 blocks subsequent to immersion in water. Theprotective coating used on the Type 2 blocks shall not changetheir ultrasonic characteristics.6.4 Anumber of impor
39、tant variables that affect the responsefrom reference blocks can be controlled during fabrication byaccurate machining practices. The roughness of the entrysurface; the alignment of entry surface, hole bottom, and backsurface; and the surface condition of the hole bottom are themore important physic
40、al variables that must be controlledduring the fabrication of reference blocks. The quality ofmaterial used for blocks also is a factor.7. Material7.1 The recommended material for reference blocks is7075-T6 aluminum alloy rolled or extruded rod (see 13.2).NOTE 4To normalize ultrasonic transmission c
41、haracteristics, the barstock may be re-heat treated prior to manufacturing the blocks. If thisoption is elected, a recommended practice is soaking at 870 6 10F (4656 5C) for a period of 1 h 6 5 min, quenching immediately by immersingvertically into water at room temperature, aging in air at room tem
42、peraturefor 4 days 61 h, followed by air aging at 250 6 10F (120 6 5C) for 246 1 h. To minimize distortion during vertical quenching, it is recom-mended that stock be re-heat treated in lengths of approximately 20 in.(508 mm).7.2 The stock shall not be less than 2.00 in. (50.8 mm) normore than 2.25
43、in. (57.2 mm) in diameter and up to 6.75 in.(171 mm) in length for the blocks covered by this practice.8. Quality of Material8.1 The quality of material to be used for reference blocksshould be checked by the procedure outlined in 8.2 to 8.9inclusive. Only material passing the requirements given in
44、8.9should be used for blocks.8.2 Evaluation ProcedureThe general evaluation proce-dure consists of directing a beam of pulsed longitudinal wavesinto the stock in a diametrical direction and noting theultrasonic noise level. An ultrasonic test by the immersionmethod using clean water that is free of
45、air bubbles as acouplant is employed for this evaluation.8.3 Test InstrumentAny of several commercially availablepulse-echo type ultrasonic testing instruments that provide a10-MHz test frequency may be used for evaluation of stockquality. The instrument should be capable of providing therequired se
46、nsitivity level with negligible internal electricalnoise and should provide linear amplification of receivedpulses in an amplitude range of at least 50 % of maximumamplitude of indication on its display screen.TABLE 2 Diameter of Flat-Bottom Holes in Inch-Pound Units andthe Nearest Metric Drill Hole
47、 DiameterNOTE 1Ratio of the area of the nearest metric drill size to the area ofthe inch-pound drill size is 1.016 throughout.Hole Diameter in Inch-Pound Units, in.Nearest Metric DrillSize, mm1/64 0.402/64 0.803/64 1.204/64 1.605/64 2.006/64 2.407/64 2.808/64 3.20TABLE 3 Dimensions and Identificatio
48、n of Reference Blocks inthe Area-Amplitude Set (see Fig. 1)BlockIdenti-ficationNumberHoleDiameter(A)MetalDistance(B)OverallLength(C)164 thsin.in. mm in. mm1-0300 1 3.000 76.2 3.750 95.32-0300 2 3.000 76.2 3.750 95.33-0300 3 3.000 76.2 3.750 95.34-0300 4 3.000 76.2 3.750 95.35-0300 5 3.000 76.2 3.750
49、 95.36-0300 6 3.000 76.2 3.750 95.37-0300 7 3.000 76.2 3.750 95.38-0300 8 3.000 76.2 3.750 95.3TABLE 4 Dimensions and Identification of Reference Blocks inDistance-Amplitude Sets (see Fig. 1 and refer to 6.2.3)Block Identifica-tion Number, 3-,5-, and 8-AMetal Distance (B) Overall Length (C)in. mm in. mm0006B0.0625 1.6 0.812 20.60012B0.125 3.2 0.875 22.20025B0.250 6.4 1.000 25.40038B0.375 9.5 1.125 28.60050B0.500 12.7 1.250 31.80062B0.625 15.9 1.375 34.90075B0.750 19.1 1.500 38.10088B0.875 22.2 1.625 41.30100B1.000 25.4 1.750 44.50125B1.250 31.
