1、Designation: E1251 17E1251 17aStandard Test Method forAnalysis of Aluminum and Aluminum Alloys by SparkAtomic Emission Spectrometry1This standard is issued under the fixed designation E1251; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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. Scope1.1 This test me
3、thod describes the analysis of aluminum and its alloys by atomicspark-atomic emission spectrometry.spectrometry (Spark-AES). The aluminum specimen to be analyzed may be in the form of a chill cast disk, casting, foil, sheet,plate, extrusion, or some other wrought form or shape. The elements covered
4、in the scope of this method are listed in the tablebelow.ElementTested Concentration Mass FractionRange(Wt %)Antimony 0.001 to 0.003Arsenic 0.001 to 0.006Beryllium 0.0004 to 0.24Bismuth 0.03 to 0.6Boron 0.0006 to 0.009Calcium 0.0002 to Chromium 0.001 to 0.23Cobalt 0.4 to Copper 0.001 to 5.5Gallium 0
5、.02 to Iron 0.2 to 0.5Lead 0.04 to 0.6Lithium 0.0003 to 2.1Magnesium 0.03 to 5.4Manganese 0.001 to 1.2Nickel 0.005 to 2.6Phosphorus 0.003 to Silicon 0.07 to 16Sodium 0.003 to 0.02Strontium 0.03 to Tin 0.03 to Titanium 0.001 to 0.12Vanadium 0.002 to 0.022Zinc 0.002 to 5.7Zirconium 0.001 to 0.12NOTE 1
6、The concentration mass fraction ranges given in the above scope were established through cooperative testing (ILS) of selected referencematerials. The range shown for each element does not demonstrate the actual usable analytical range for that element. The usable analytical range maybe extended hig
7、her or lower based on individual instrument capability, spectral characteristics of the specific element wavelength being used, and theavailability of appropriate reference materials.NOTE 2Mercury (Hg) is intentionally not included in the scope. Analysis of Hg in aluminum by spark atomic emission sp
8、ectrometry (Spark-AES)Spark-AES is not recommended.Accurate analysis of Hg using this technique is compromised by the presence of an intense iron interference. Inaccuratereporting of Hg due to these interference effects can jeopardize the current designation of aluminum production as a mercury-free
9、process. To demonstratecompliance with legislated Hg content limits, use of an alternate method capable of analysis with a minimum reporting limit of 0.0001% or lower isrecommended. Suitable techniques include but are not limited to glow discharge mass spectrometry, XRF, and cold vapor AA.GD-MS, XRF
10、 (X-rayfluorescence), cold vapor AA, and ICP-MS.1.2 This test method is suitable primarily for the analysis of chill cast disks as defined in Practices E716. Other forms may beanalyzed, provided that: (1) they are sufficiently massive to prevent undue heating, (2) they allow machining to provide a c
11、lean,1 This test method is under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and is the direct responsibility ofSubcommittee E01.04 on Aluminum and Magnesium.Current edition approved Sept. 15, 2017Oct. 1, 2017. Published October 2017. Origin
12、ally approved in 1988. Last previous edition approved in 20112017 asE1251 11.E1251 17. DOI: 10.1520/E1251-17.10.1520/E1251-17A.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Beca
13、useit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 B
14、arr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1flat surface, which creates a seal between the specimen and the spark stand, and (3) reference materials of a similar metallurgicalcondition and chemical composition are available.1.3 This standard does not purport to add
15、ress all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability ofregulatory limitations prior to use. Specific safety and health statements are
16、 given in Section 10.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Tec
17、hnical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B985 Practice for SamplingAluminum Ingots, Billets, Castings and Finished or Semi-Finished WroughtAluminum Products forCompositional AnalysisE29 Practice for Using Significant Digits in Test Data to Determine Conform
18、ance with SpecificationsE135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related MaterialsE158 Practice for Fundamental Calculations to Convert Intensities into Concentrations in Optical Emission SpectrochemicalAnalysis (Withdrawn 2004)3E172 Practice for Describing and Specify
19、ing the Excitation Source in Emission Spectrochemical Analysis (Withdrawn 2001)3E305 Practice for Establishing and Controlling Atomic Emission Spectrochemical Analytical CurvesE406 Practice for Using Controlled Atmospheres in Spectrochemical AnalysisE691 Practice for Conducting an Interlaboratory St
20、udy to Determine the Precision of a Test MethodE716 Practices for Sampling and Sample Preparation of Aluminum and Aluminum Alloys for Determination of ChemicalComposition by Spark Atomic Emission SpectrometryE826 Practice for Testing Homogeneity of a Metal Lot or Batch in Solid Form by Spark Atomic
21、Emission SpectrometryE876 Practice for Use of Statistics in the Evaluation of Spectrometric Data (Withdrawn 2003)3E1329 Practice for Verification and Use of Control Charts in Spectrochemical AnalysisE1507 Guide for Describing and Specifying the Spectrometer of an Optical Emission Direct-Reading Inst
22、rument2.2 ANSI Standard:4ANSI H35.1/H35.1M American National Standard Alloy and Temper Designation Systems for Aluminum3. Terminology3.1 DefinitionsFor definitions of terms used in this Standard, refer to Terminology E135.3.2 Definitions of Terms Specific to This Standard:3.2.1 alloy-type calibratio
23、ncalibration curves determined using calibrants calibration materials from alloys with similarcompositions.3.2.2 binary-type calibrationcalibration curves determined using binary calibrants calibration materials (primary aluminumto which has been added one specific element).3.2.3 global-type calibra
24、tioncalibration curves determined using calibrants calibration materials from many different alloyswith considerable compositional differences.3.2.4 two-point drift correctionthe practice of analyzing a high and low standardant standardization materials for eachcalibration curve and adjusting the co
25、unts or voltage values intensities obtained back to the values obtained on those particularstandardants standardization materials during the collection of the calibration data. The corrections are accomplished mathemati-cally and are applied to both the slope and intercept. Improved precision may be
26、 obtained by using a multi-point drift correctionas described in Practice E1329.3.2.5 type standardizationmathematical adjustment of the calibration curves slope or intercept using a single standardant(reference material) standardization materials at or close to the nominal composition for the parti
27、cular alloy being analyzed. Forbest results, the standardant standardization material being used should be within 610 % of the composition (for each respectiveelement) of the material being analyzed.4. Summary of Test Method4.1 A unipolar triggered capacitor controlled electrical discharge is produc
28、ed in an argon atmosphere between the prepared flatsurface of a specimen and the tip of a semi-permanent counter electrode. The energy of the discharge is sufficient to ablate material2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.
29、org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.4 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, N
30、ew York, NY 10036, http:/www.ansi.org.E1251 17a2from the surface of the sample, break the chemical or physical bonds, and cause the resulting atoms or ions to emit radiant energy.The radiant energies of the selected analytical lines and the internal standard line(s) are converted into electrical sig
31、nals by eitherphotomultiplier tubes (PMTs) or a suitable solid state detector. The detector signals are electrically integrated and converted to adigitized value. The signals are ratioed to the proper internal standard signal and converted into concentrations by a computer massfractions in accordanc
32、e with Practice E158.4.2 Three different methods of calibration defined in 3.2.2, 3.2.3, and 3.2.1 are capable of giving the same precision, accuracy,and detection limit.4.2.1 The first method, binary calibration, employs calibration curves that are determined using a large number of high-puritybina
33、ry calibrants. calibration materials. This approach is used when there is a need to analyze almost the entire range of aluminumalloys. Because binary calibrants calibration materials may respond differently from alloy calibrants, calibration materials, thelatter are used to improve accuracy by apply
34、ing a slope and/or intercept correction to the observed readings.4.2.2 The second method, global calibration, employs calibration curves that are determined using many different alloycalibrants calibration materials with a wide variety of compositions. Mathematical calculations are used to correct f
35、or both alloydifference and inter-element effects. Like the method above, specific alloy calibrants calibration materials may be used to applya slope and/or intercept correction to the observed readings.4.2.3 The third method, alloy calibration, employs calibration curves that are determined using d
36、ifferent alloy calibrantscalibration materials that have similar compositions. Again, specific alloy calibrants calibration materials may be used to apply aslope and/or intercept correction to the observed readings.5. Significance and Use5.1 The metallurgical properties of aluminum and its alloys ar
37、e highly dependent on chemical composition. Precise and accurateanalyses are essential to obtaining desired properties, meeting customer specifications, and helping to reduce scrap due to off-gradematerial.5.2 This test method is applicable to chill cast specimens as defined in Practices E716 and ca
38、n also be applied to other typesof samples provided that suitable reference materials are available. Also, other sample forms can be melted down and cast into adisk, using an appropriate mold, as described in Practices E716. However, it should be noted that some elements (for example,magnesium) read
39、ily form oxides, while some others (for example, sodium, lithium, calcium, and strontium) are volatile, and maybe lost to varying degrees during the melting process.6. Recommended Analytical Lines and Potential Interferences6.1 Table 1 lists the analytical lines commonly used for aluminum analysis.
40、Other lines may be used if they give comparableresults. Also listed are recommended concentration mass fraction ranges, background equivalent concentrations (BEC),massfractions, detection limits, useful linear ranges, and potential interferences. The values given in this table are typical; actual va
41、luesobtained are dependent on instrument design.NOTE 3The BEC background equivalent mass fraction and detection limits listed in Table 1 have been attained with a spectrometer that has areciprocal dispersion of 54 nm/mm and a working resolution of 3.5 nm, using an entrance slit width of 25 m and exi
42、t slit widths of 50 m.7. Apparatus7.1 Specimen Preparation Equipment:7.1.1 Sampling Molds, for aluminum and the techniques of pouring a sample disk are described in Practices E716. Chill castsamples, poured and cast as described within Practices E716, shall be the recommended form in this test metho
43、d.7.1.2 Lathe, capable of machining a smooth, flat surface on the reference materials and samples. A variable speed cutter, acemented carbide or polycrystalline diamond tool bit, and an automatic cross feed are highly recommended. Proper depth of cutand desired surface finish are described in Practi
44、ces E716.7.1.3 Milling Machine, a milling machine can be used as an alternative to a lathe.7.1.4 Milling Machine, a milling machine can be used as an alternative to a lathe.It is strongly recommended that the samepreparation machinery used to prepare the standards is also used to prepare the samples
45、. Differences in surface characteristics mayinfluence the analysis.NOTE 4It is strongly recommended that the same preparation machinery used to prepare the standards is also used to prepare the samples. Differencesin surface characteristics may influence the analysis.7.2 Excitation Source, Sourcecap
46、able of producing a unipolar, triggered capacitor discharge. In todays instrumentation, theexcitation source is computer controlled and is normally programmed to produce: (1) a high-energy pre-spark (of some presetduration), (2) a spark-type discharge (of some preset duration), (3) an arc-type disch
47、arge (of some preset duration), and (4) aspark-type discharge, during which, time-resolved measurements are made for improved detection limits (this may be optional onsome instruments).7.2.1 Typical parameters and exposure times are given in Table 2. It should be emphasized that the information pres
48、ented isgiven as an example only and parameters may vary with respect to instrument model and manufacturer. For details on describingand specifying an excitation source, please refer to Practice E172.E1251 17a3TABLE 1 Recommended Analytical LinesElementWavelengthin Air(nm)ARecommendedConcentrationMa
49、ssFractionRange, %BackgroundEquivalent,%BCalculatedDetectionLimit, %C,DHighConcentrationMassFractionIndex, %EInterferencesElement, (nm) and k, %FAluminum I 256.799 70-100Aluminum 256.799 I 70-100I 266.039 70-100266.039 I 70-100I 237.208 70-100237.208 I 70-100Antimony I 231.147 0.001-0.5 0.17 0.0002 Co 231.166 0.6Antimony 231.147 I 0.001-0.5 0.17 0.0002 Co 231.166 0.6I 259.806 0.001-0.5 0.0002 Fe 259.837259.806 I 0.001-0.5 0.0002 Fe 259.837Mn 259.817 0.01Arsenic 234.984 I 0.005-0.1Beryllium I 234.861 0.0001-0.05 0.001 0.00003Beryllium 234.861 I 0.0001-0.0
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