1、Designation: E127 10E127 15Standard Practice forFabricatingFabrication and Checking Control of AluminumAlloy Ultrasonic Standard Reference Blocks1This standard is issued under the fixed designation E127; the number immediately following the designation indicates the year oforiginal adoption or, in t
2、he case of revision, the year 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 standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope Sc
3、ope*1.1 This practice covers a procedure for fabricating aluminum alloy ultrasonic standard reference blocks that can be used forcheckingassessing performance of ultrasonic testing equipment and for standardization and control of ultrasonic tests of aluminumalloy products using pulsed longitudinal w
4、aves introduced into test material either by the direct-contact method or by theimmersion method. A recommended procedure for checking blocks is described and calibration data for a number of referenceblocks are tabulated. Statements concerning procedures are provided without a discussion of the tec
5、hnical background for thepreference. The necessary technical background can be found in Refs. (1-1518).2NOTE 1Practice E428 and Guide E1158 also describe procedures for selecting material, fabricating blocks, and checking response. Unlike thispractice, there is no requirement for evaluation relative
6、 to a specified standard target.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitation
7、s prior to use.2. Referenced Documents2.1 ASTM Standards:3E317 Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-EchoTesting Instruments and Systems without theUse of Electronic Measurement InstrumentsE428 Practice for Fabrication and Control of Metal, Other than Aluminum, Refe
8、rence Blocks Used in Ultrasonic TestingE1065 Practice for Evaluating Characteristics of Ultrasonic Search UnitsE1158 Guide for Material Selection and Fabrication of Reference Blocks for the Pulsed Longitudinal Wave Ultrasonic Testingof Metal and Metal Alloy Production MaterialE1316 Terminology for N
9、ondestructive ExaminationsE1324 Guide for Measuring Some Electronic Characteristics of Ultrasonic Testing InstrumentsE2375 Practice for Ultrasonic Testing of Wrought ProductsB594 Practice for Ultrasonic Inspection of Aluminum-Alloy Wrought Products3. Terminology3.1 DefinitionsFor definitions of term
10、s not specific to this practice, refer to Terminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 angular errorthe condition observed in ultrasonic tests of reference blocks when the response from the hole bottom isnot maximum while the search unit is positioned to obtain either a
11、 maximum number of back reflections from a reference blockor a maximum indication from its entry surface. Angular error results when the entry surface, hole bottom, and back surface arenot parallel to each other.3.2.2 area-amplitude response curvea curve showing the relationship between different ar
12、eas of reflecting targets located ata constant distance in an ultrasonic transmitting medium and their respective amplitudes of ultrasonic response.1 This practice is under the jurisdiction ofASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.06 on Ultr
13、asonic Method.Current edition approved Feb. 15, 2010June 1, 2015. Published March 2010June 2015. Originally approved in 1958. Last previous edition approved in 20072010 asE127 - 07.E127-10. DOI: 10.1520/E0127-10.10.1520/E0127-15.2 The boldface numbers in parentheses refer to the list of references a
14、t the end of this practice.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM stand
15、ard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases
16、 only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.3 back reflec
17、tionthe indication, observed on the display screen of a test instrument, that represents the ultrasonic energyreflected from the back surface of a reference block.3.2.4 back surfacethe end of a reference block that is opposite the entry surface.3.2.3 entry surfacethe end of a reference block through
18、 which ultrasonic energy must pass when reflections from the holebottom are obtained.3.2.4 hole bottomthe flat reflecting surface in a reference block that is obtained by making the entire end of a drilled holesmooth and flat using best machining practices. The hole bottom is parallel to the entry s
19、urface of the block.3.2.5 hole sizethe diameter of the hole in a reference block that determines the area of the hole bottom.3.2.6 metal distancethe distance in a reference block from its entry surface to the hole bottom.3.2.9 reference blockan aluminum block, containing as an artificial discontinui
20、ty 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 represents theamount of ultrasonic energy initially reflected from the hole bottom in a reference block. Units usually used in measuring heighto
21、f indication are inches, trace-to-peak, or percent of upper linearity limit.4. Summary of Practice4.1 Aluminum alloy stock is ultrasonically evaluated to ensure freedom from significant discontinuities and is then preciselyfabricated into cylindrical blocks of prescribed lengths.Asingle, flat-bottom
22、 hole of specific diameter is drilled to a constant depthinto the end of each block at its center, and the blocks are grouped into sets according to hole size and block length, or metaldistance.4.2 Each block is checked ultrasonically using a calibrated ultrasonic test system at a prescribed test fr
23、equency. Distance-amplitude and area-amplitude characteristics are established for sets of fabricated blocks using specific reflectors to provide astandard response. Curves are plotted to establish the interrelationship between the various blocks in the sets.4.3 To permit the use of instrumentation
24、similar to that originally used in developing this practice, or types more recentlymanufactured, two alternative test system calibration procedures are described. The first method (ball-to-block) which utilizes steelballs as reference standards, is covered in 11.8.2. The second method (block-to-bloc
25、k), which requires as reference standards,blocks which have been calibrated by the National Institute of Standards and Technology (NIST), is described in Annex A1.45. Significance and Use5.1 Reference blocks fabricated to this practice will exhibit specific area-amplitude and distance-amplitude rela
26、tionships onlywith an immersion test at 5 MHz using the search unit, test instrument, and test parameters described in this practice. Comparisontests at other frequencies or with uncalibrated test systems will not necessarily give the same relationships shown in this practice.NOTE 2The 1964 and prio
27、r issues of this practice required a test frequency of 15 MHz. Blocks conforming to earlier issues of this practice may notproduce ultrasonic responses that conform to this issue. See Section 13 regarding provision for recertification or correction curves and tables.5.2 Although the primary ultrason
28、ic evaluation of blocks is performed at a specified frequency, the blocks may be used tostandardize ultrasonic tests at any frequency and with any pulse-echo ultrasonic test system. Establishment of distance-amplitudeand area-amplitude characteristics is necessary for each application. This use may
29、be inappropriate for other materials and curvedsurfaces without special compensation. Also see (3) for cautions regarding use of standard blocks for test standardization.6. Description of Various Recommended Sets6.1 In ultrasonic testing of aluminum alloy products, a standard reference usually is ne
30、cessary to establish a specified testsensitivity. A standard ultrasonic reference also is required frequently to determine the effect of variations in metal distance uponthe ultrasonic response from detected discontinuities. Test sensitivity standardizations and corrections for metal distance are mo
31、streliable when made under the same conditions employed for the actual tests. For these purposes, aluminum alloy reference blockscontaining various combinations of hole size and metal distance are necessary.6.2 The following combinations or sets of blocks are recommended:6.2.1 Basic SetThe basic set
32、 consisting of ten reference blocks is listed in Table 1. Area-amplitude relations are obtainedby intercomparison of blocks containing the 3-in. (76.2-mm) metal distance and 364-in., 564-in., and 864- in. (see Note 32) diameterholes, respectively. Distance-amplitude relations are obtained by interco
33、mparison of the blocks of various lengths which contain564-in. diameter holes.NOTE 2Direct conversion from inches to millimetres (1 in. = 25.4 mm) gives hole size dimensions for which there are no standard metric drills;however, Table 2 gives the nearest standard metric drill size.6.2.2 Area-Amplitu
34、de SetThe area-amplitude set consisting of eight ultrasonic standard reference blocks is listed in Table 3.Area-amplitude relationships are obtained by intercomparison of any three or more blocks with different flat bottom-hole sizes atthe same metal distance from front surface to hole bottom.E127 1
35、526.2.3 Distance-Amplitude SetA distance-amplitude set may include any convenient number of the reference blocks shown inTable 4 and does not necessarily include all blocks listed. A recommended distance-amplitude set contains at least 12 blocks, andeach set contains only one of the three hole sizes
36、 shown in Table 4. Blocks comprising the 19 block distance-amplitude sets, whichare customarily supplied commercially, are indicated in Table 4. Increments of metal distance in each of the three groups of blocksin the recommended set should be identical. Distance-amplitude relationships are obtained
37、 by intercomparison of all blockscontaining the same size hole.6.3 If the blocks are to be used for immersion testing, they should be suitably anodized or otherwise protected to enhanceresistance to corrosion. Blocks with coated surfaces may be used with search units requiring external ground provid
38、ed suitablearrangements are made for adequate electrical contact. Uncoated blocks shall be designated as Type 1; coated blocks shall bedesignated as Type 2. The ultrasonic characteristics of both types shall be checked by the immersion method as prescribed inSection 11. However, care must be exercis
39、ed to dry the Type 1 blocks subsequent to immersion in water. The protective coatingused on the Type 2 blocks shall not change their ultrasonic characteristics.6.4 A number of important variables that affect the response from reference blocks can be controlled during fabrication byaccurate machining
40、 practices. The roughness of the entry surface; the alignment of entry surface, hole bottom, and back surface;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
41、3 3.000 76.2 3.750 95.25-0012 5 0.125 3.2 0.875 22.25-0025 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 6.750 171.4TABLE
42、 2 Diameter of Flat-Bottom Holes in Inch-Pound Units andthe Nearest Metric Drill Hole 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
43、1.204/64 1.605/64 2.006/64 2.407/64 2.808/64 3.20TABLE 3 Dimensions and Identification 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.
44、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 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 95.3E127 153and the surface condition of the hole bottom are the more important physical variables that must be controlled
45、during thefabrication of reference blocks. The quality of material used for blocks also is a factor.7. Material7.1 The recommended material for reference blocks is 7075-T6 aluminum alloy rolled or extruded rod (see wrought aluminumalloys.13.2).NOTE 4To normalize ultrasonic transmission characteristi
46、cs, the bar stock may be re-heat treated prior to manufacturing the blocks. If this optionis elected, a recommended practice is soaking at 870 6 10F (465 6 5C) for a period of 1 h 6 5 min, quenching immediately by immersing verticallyinto water at room temperature, aging in air at room temperature f
47、or 4 days 61 h, followed by air aging at 250 6 10F (120 6 5C) for 24 6 1 h. Tominimize distortion during vertical quenching, it is recommended 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) nor more than 2.25 in. (57.
48、2 mm) in diameter and up to 6.75 in. (171mm) in length for the blocks covered by this practice. Other sizes (diameters and lengths) may be used when agreed upon by thecustomer and user of the standard.8. Quality of Material Selection8.1 The quality of material to be used for reference blocks should
49、be checked by the procedure outlined insimilar in its acousticattenuation to the material which is 8.2to 8.9 inclusive. Only material passing the requirements given inbe examined. The grainsize, heat treat condition, physical 8.9 should be used for blocks.and chemical composition, surface finish, and manufacturingprocedure (rolling, forging, and so forth) are variables to be considered in matching acoustic responses.8.2 Evaluation ProcedureThe general evaluation procedure consists of directing a beam of pulsed longitudinal waves into thestock in a di
