1、Designation: A900/A900M 01 (Reapproved 2012)Standard Test Method forLamination Factor of Amorphous Magnetic Strip1This standard is issued under the fixed designation A900/A900M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers measurements of laminationfactor (Note 1) of a specimen composed of strips cut fromamor
3、phous magnetic material. It is suitable for the determina-tion of lamination factor for thin, flat case, metallic stripranging in width from 0.25 to 8.00 in. 6.35 mm to 203 mmand in thickness from 0.0005 to 0.005 in. 12.7 to 127 m.NOTE 1Lamination factor is also termed space factor or stackingfactor
4、.1.2 The values and equations stated in customary (egs-emuand inch-pound) or SI units are to be regarded separately asstandard. Within this standard, SI units are shown in brackets.The values stated in each system may not be exact equivalents;therefore, each system shall be used independently of the
5、 other.Combining values from the two systems may result in noncon-formance with this standard.1.3 This standard 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 pra
6、ctices and determine the applica-bility of regulatory limitations prior to use.2. Summary of Test Method2.1 The laminated test specimen is oriented and aligned,then subjected to pressure in a compression device. Theresulting volume is then determined from the measured speci-men height, width, and le
7、ngth. An equivalent solid volume iscalculated from the specimen mass and the true density of thespecimen material. The ratio of the calculated (equivalentsolid) volume to the measured volume is the lamination factor.3. Significance and Use3.1 Lamination factor S indicates the deficiency of effective
8、material volume which is due to the presence of oxides,roughness, insulating coatings, and other conditions affectingthe strip surface.3.2 This test method is used to predict the fraction of metalthat is included in the volume of the firm coil wound from thespecimen tape.4. Interferences4.1 This tes
9、t method is predicated on correctly aligned teststrips and uniform compression during test. Both of theseconditions are difficult to meet whenever the test specimenshave one or more elevated ridges running lengthwise along thesurface of the strip.4.2 This test method also presupposes that the test s
10、peci-mens are free from other defects, such as camber and waviness,that may affect the lamination factor.5. Apparatus5.1 MicrometersTwo types of micrometers are includedfor use in this test method as follows:5.1.1 Motor-Operated, Deadweight (Not Spring) ActuatedMicrometer, conforming to the followin
11、g requirements:5.1.1.1 The micrometer shall be a deadweight digital- ordial-type micrometer, having two ground and lapped circularsurfaces with a capacity of not less than 0.030 in. 0.75 mm.The movable face or presser foot shall have an area of 0.25 to0.33 in.2160 to 215 mm2 and corresponding to a d
12、iameter ofapproximately 0.56 to 0.65 in. 14.2 to 16.5 mm. The fixedface or anvil shall be of such size that the whole area of thepresser foot is in contact with the anvil in the zero position.5.1.1.2 The surface shall be parallel to within 0.000 05 in.0.0012 mm and the presser foot shall move on an
13、axisperpendicular to the anvil.5.1.1.3 The presser foot shall exert a steady pressure on thespecimen of 7.0 to 8.0 psi 48 to 55 kPa.5.1.1.4 A digital readout is preferred. If an analog gauge isused, the dial shall be at least 2 in. 51 mm in diameter. It shallbe continuously graduated to read directl
14、y to 0.0001 in.0.0025 mm and shall be required with a telltale hand, ifnecessary, recording the number of complete revolutions of thelarge hand.5.1.1.5 The micrometer shall be capable of repeating itsreadings to 0.000 05 in. 0.0012 mm at zero setting or on asteel gauge block.5.1.1.6 The deviations f
15、or the parts of the scale correspond-ing to the specimen thickness measured shall be applied ascorrections to the thickness reading.1This test method is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.01 on TestMethods.Current e
16、dition approved May 1, 2012. Published July 2012. Originally approvedin 1991. Last previous edition approved in 2006 as A900/A900M01(2006). DOI:10.1520/A0900_A0900M-01R12.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1.7 The fra
17、me of the micrometer shall be of such rigiditythat a load of 3 lb 1.5 kg applied to the dial housing, out ofcontact with either the weight or the presser foot spindle, willproduce a deflection of the frame not greater than 0.0001 in.0.0025 mm, as indicated on the micrometer dial.5.2 Manually Operate
18、d Deadweight (Not Spring) ActuatedDial-Type Micrometer, conforming to the general requirementsof 5.1.1 to 5.1.1.7.5.3 Holding Fixture, to facilitate the aligning of the teststrips and to hold them aligned during the test, is included foruse on this test method. A sample design is given in AppendixX1
19、.6. Sampling and Test Specimens6.1 Samples shall be obtained from both the beginning andend of spool (or material lot as mutually agreed upon betweenproducer and consumer) and undergo testing separately.6.2 The test specimen shall consist of a stack of identicallength test strips, cut from the sampl
20、e coil, and shall bebetween 10 and 30 in number, depending on the strip thickness,as indicated in 6.5. The strip shall be cut consecutively fromthe sample coil as shown in Fig. 1 and the identical lengthselection shall be within the range of 3 to 5 in. 76 to 127 mm.6.3 Amorphous alloys are manufactu
21、red by pouring moltenmetal on a rapidly spinning chill-wheel and periodic thicknessvariations, if any, will be related to the position on the wheelcircumference. To ensure that such variations are properlyaveraged, the total length of tape used in this test should be inmultiples of the wheel circumf
22、erence.6.4 If the exact chill-wheel diameter is not known, it can beassumed to be 15 in., that is, 47.12 in. 120 cm in circumfer-ence. Most of the material currently made requires 20 strips forthe lamination factor test; therefore, 12-cm-long test stripswould use exactly two wheel circumferences of
23、sample tape.6.5 The number of laminations needed to maintain the stackheight in the 15- to 30-mil range is indicated as follows:Thickness of Tape, mils (m)Number ofStrips Needed0.500.74 (1319) 300.741.50 (2038) 201.513.00 (3976) 107. Procedure7.1 Select a representative segment from each sample ofma
24、terial to be tested and cut the required number of strips asspecified in 6.5 to a length as specified in 6.2.7.2 Stack the test strips directly on top of one another in thealigning fixture. Maintain the proper directionally as in Fig. 2.7.3 Align the edges of the strips and secure the stack byclampi
25、ng.7.4 Determine the maximum thickness of the specimenstack by making multiple measurements across the entirewidth, at intervals slightly smaller than the presser foot of themicrometer, to ensure a small overlap in the area covered. Themaximum height measured is recorded and used in the lami-nation
26、factor computation.8. Calculation8.1 Using the thickness value measured in 7.4, calculate thepercent lamination factor as follows:S 5mlwdhkwhere:S = lamination factor, % %;m = mass of specimen, g kg;w = width, mm mm;h = thickness, m m;d = density of specimen material, g/cm3kg/m3;l = length of test s
27、trips, cm m; andk = equation constant, 1071011.8.2 Length and width dimensions should be known to anaccuracy of at least 60.25 % and preferably to 60.1 %.9. Precision and Bias9.1 It has been statistically determined that a firm toroid (orcoil) of amorphous ribbon with precisely aligned edges, willha
28、ve a lamination factor within 62.0 % of the value predictedby this test method.9.2 The bias of measurement with this method may decreaseto 65.0 % if the thickness variation across the strip width ismore than 10 %.10. Keywords10.1 amorphous material; lamination factor; space factor;stacking factorFIG
29、. 1 Ribbon Length for Lamination Factor Testing With Refer-ence MarksFIG. 2 Orientation of Stack SpecimenA900/A900M 01 (2012)2APPENDIX(Nonmandatory Information)X1. APPARATUSX1.1 Automatic MicrometerTo measure the laminationfactor on a large number of samples, an automatic micrometermay be preferred.
30、 Such equipment has been designed formeasuring paper thickness (see Fig. X1.1 and Fig. X1.2).X1.2 Holding FixtureAdrill-press vise can be modified toserve as a suitable sample holder by extending the jaws toconform with the width of the test material (see Fig. X1.3).X1.2.1 The two steel plates shoul
31、d be parallel to each otherand normal to the base. Stainless steel is preferred to avoidcorrosion. The plates should be of sufficient thickness toprevent flexing. A good rule is to use116 in. 1.6 mm ofthickness per 1 in. 25 mm of extension above the vise.X1.2.2 The blunt end of the vise should be gr
32、ound parallelto the jaw plates and the thickness adjusted to align the bottomof the sample stack with the anvil of the micrometer (See Fig.X1.2).NOTE 1On the left is a lathe vise, modified with steel plates to extend the reach of jaws, in position for loading and aligning the strips.FIG. X1.1 Automa
33、tic Digital Micrometer for Thickness MeasurementA900/A900M 01 (2012)3NOTE 1The amorphous strips extend over the anvil of the micrometer.FIG. X1.2 Holding Fixture in Position for Thickness MeasurementFIG. X1.3 Drill-Press Vise Modified With Long Jaws to Serve as a Sample Holder for Thickness Measurem
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37、nown to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).A900/A900M 01 (2012)5
