1、Designation: A900/A900M 01 (Reapproved 2018)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, health, and e
6、nvironmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Sta
7、ndards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.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 m
8、easured speci-men height, width, and length. 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
9、S indicates the deficiency of effectivematerial 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 thespe
10、cimen tape.4. Interferences4.1 This test 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
11、method also presupposes that the test speci-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) Actuate
12、dMicrometer, conforming to the following 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.2
13、160 to 215 mm2 and corresponding to a diameter 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
14、 and the presser foot shall move on an 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
15、 continuously graduated to read directly 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.1This test method is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibil
16、ity of Subcommittee A06.01 on TestMethods.Current edition approved May 1, 2018. Published June 2018. Originallyapproved in 1991. Last previous edition approved in 2012 as A900/A900M 01(2012). DOI: 10.1520/A0900_A0900M-01R18.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consh
17、ohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Org
18、anization Technical Barriers to Trade (TBT) Committee.15.1.1.5 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 for the parts of the scale correspond-ing to the specimen thickness measured shall be appl
19、ied ascorrections to the thickness reading.5.1.1.7 The frame 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
20、, as indicated on the micrometer dial.5.2 Manually Operated 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 o
21、n this test method. A sample design is given in AppendixX1.6. 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
22、a stack of identicallength test strips, cut from the sample 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
23、3 to 5 in. 76 to 127 mm.6.3 Amorphous alloys are manufactured 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 us
24、ed in this test should be inmultiples of the wheel circumference.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
25、 test stripswould use exactly two wheel circumferences of 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. Procedur
26、e7.1 Select a representative segment from each sample ofmaterial 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 A
27、lign the edges of the strips and secure the stack byclamping.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. Themaximu
28、m height measured is recorded and used in the lami-nation factor computation.8. Calculation8.1 Using the thickness value measured in 7.4, calculate thepercent lamination factor as follows:S 5mlwhkwhere:S = lamination factor, % %;m = mass of specimen, g kg;w = width, mm mm;h = thickness, m m; = densi
29、ty of specimen material, g/cm3kgm3;l = length of test strips, 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) o
30、f amorphous ribbon with precisely aligned edges, willhave 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 mater
31、ial; lamination factor; space factor;stacking factorFIG. 1 Ribbon Length for Lamination Factor Testing With Refer-ence MarksFIG. 2 Orientation of Stack SpecimenA900/A900M 01 (2018)2APPENDIX(Nonmandatory Information)X1. APPARATUSX1.1 Automatic MicrometerTo measure the laminationfactor on a large numb
32、er of samples, an automatic micrometermay be preferred. 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 mat
33、erial (see Fig. X1.3).X1.2.1 The two steel plates should 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
34、 the vise.X1.2.2 The blunt end of the vise should be ground 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 positi
35、on for loading and aligning the strips.FIG. X1.1 Automatic Digital Micrometer for Thickness MeasurementA900/A900M 01 (2018)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
36、Jaws to Serve as a Sample Holder for Thickness MeasurementA900/A900M 01 (2018)4ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the vali
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