1、Designation: E2994 16Standard Test Method forAnalysis of Titanium and Titanium Alloys by Spark AtomicEmission Spectrometry and Glow Discharge AtomicEmission Spectrometry (Performance-Based Method)1This standard is issued under the fixed designation E2994; the number immediately following the designa
2、tion indicates the year oforiginal adoption or, in the 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.1. Scope1.1 This test method describes the an
3、alysis of titanium andits alloys by spark atomic emission spectrometry (Spark-AES)and glow discharge atomic emission spectrometry (GD-AES).The titanium specimen to be analyzed may be in the form of adisk, casting, foil, sheet, plate, extrusion or some other wroughtform or shape. The elements and ran
4、ges covered in the scopeby spark-AES of this method are listed below.ElementTested MassFractionRange (%)Aluminum 0.008 to 7.0Chromium 0.006 to 0.1Copper 0.014 to 0.1Iron 0.043 to 0.3Manganese 0.005 to 0.1Molybdenum 0.014 to 0.1Nickel 0.006 to 0.1Silicon 0.018 to 0.1Tin 0.02to0.1Vanadium 0.015 to 5.0
5、Zirconium 0.013 to 0.11.1.1 The elements oxygen, nitrogen, carbon, niobium,boron, yttrium, palladium, and ruthenium, were included in theILS but the data did not contain the required six laboratories.Precision tables were provided for informational use only.1.2 The elements and ranges covered in the
6、 scope byGD-AES of this method are listed below.ElementTested MassFractionRange (%)Aluminum 0.02 to 7.0Chromium 0.006 to 0.1Copper 0.028 to 0.1Iron 0.09 to 0.3Molybdenum 0.016 to 0.1Nickel 0.006 to 0.1Silicon 0.018 to 0.1Tin 0.022 to 0.1Vanadium 0.054 to 5.0ElementTested MassFractionRange (%)Zirconi
7、um 0.026 to 0.11.3 The mass fractions given in the above scope tables arethe ranges validated through the interlaboratory study.However, it is known that the techniques used in this standardallow the useable range to be extended higher or lower basedon individual instrument and laboratory capabiliti
8、es, and thespectral characteristics of the specific element wavelengthbeing used. Laboratories must provide sufficient evidence ofmethod validation when extending the analytical range asdescribed in Guide E2857 Validating Analytical Methods.1.4 This standard does not purport to address all of thesaf
9、ety 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. Specific safetyhazard statements are given in Section 9.2. Referenced Doc
10、uments2.1 ASTM Standards:2E135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE305 Practice for Establishing and Controlling AtomicEmission Spectrochemical Analytical CurvesE406 Practice for
11、Using Controlled Atmospheres in Spec-trochemical AnalysisE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1329 Practice for Verification and Use of Control Charts inSpectrochemical AnalysisE1507 Guide for Describing and Specifying the Spectrom-eter of
12、an Optical Emission Direct-Reading Instrument1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is the directresponsibility of Subcommittee E01.06 on Ti, Zr, W, Mo, Ta, Nb, Hf, Re.Current edition approved April 15, 201
13、6. Published May 2016. DOI: 10.1520/E2994-16.2For 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.Copyright ASTM I
14、nternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE2857 Guide for Validating Analytical MethodsE2972 Guide for Production, Testing, and Value Assig
15、nmentof In-House Reference Materials for Metals, Ores, andOther Related Materials2.2 ISO Standard:3ISO/IEC Guide 98-3:2008 Uncertainty of MeasurementPart 3: Guide to the Expression of Uncertainty in Mea-surement (GUM:1995)First Edition3. Terminology3.1 DefinitionsFor definitions of terms used in thi
16、sPractice, refer to Terminology E135.3.2 Definitions of Terms Specific to This Standard:3.2.1 alloy-type calibration, ncalibration curves deter-mined using reference materials from alloys with generallysimilar compositions.3.2.2 global type calibration, ncalibration curves deter-mined using referenc
17、e materials from numerous differentalloys with considerable compositional variety.3.2.3 type standardization, nmathematical adjustment ofthe calibration curves slope or intercept using a single refer-ence material at or close to the nominal composition for theparticular alloy being analyzed. For bes
18、t results the referencematerial being used should be of the same alloy family as thematerial being analyzed.4. Summary of Test Method4.1 Spark-AESA controlled electrical discharge is pro-duced in an argon atmosphere between the prepared flat surfaceof a specimen and the tip of a counter electrode. T
19、he energy ofthe discharge is sufficient to ablate material from the surface ofthe specimen, break the chemical or physical bonds, and causethe resulting atoms or ions to emit radiant energy. The radiantenergies of the selected analytical lines and the internalstandard line(s) are converted into elec
20、trical signals by eitherphotomultiplier tubes (PMTs) or a suitable solid state detector.The detected analyte signals are integrated and converted to anintensity value. A ratio of the detected analyte intensity and theinternal standard signal may be made. A calibration is madeusing a suite of referen
21、ce materials with compositional simi-larity to the specimens being analyzed. Calibration curvesplotting analyte intensity (intensity ratio) versus analyte massfraction are developed. Specimens are measured for analyteinstensity and results in mass fraction are determined using thecalibration curves.
22、4.2 GD-AESAglow discharge lamp creates a low pressureAr plasma above the sample surface by applying a highnegative voltage between the sample (cathode) and an anode.Argon ions are accelerated into the specimen, which sputtersmaterial from the surface. The sputtered material diffuses intothe argon pl
23、asma where it is dissociated into atoms and excited.The light emitted from these excited species is characteristic ofthe elements composing the sample and is converted intoelectrical signals by either photomultiplier tubes (PMTs) or asuitable solid state detector. The detected analyte signals areint
24、egrated and converted to an intensity value. A ratio of thedetected analyte intensity and the internal standard signal maybe made. A calibration is made using a suite of referencematerials with compositional similarity to the specimens beinganalyzed. Calibration curves plotting analyte intensity (in
25、ten-sity ratio) versus analyte mass fraction are developed. Speci-mens are measured for analyte instensity and results in massfraction are determined using the calibration curves.5. Significance and Use5.1 This test method for the chemical analysis of titaniumalloys is primarily intended to test mat
26、erial for compliance tocompositional requirements of specifications such as thoseunder jurisdiction of ASTM committee B10. It may also beused to test compliance with other specifications that arecompatible with the test method.5.2 This is a performance-based test method that relies moreon the demons
27、trated quality of the test result than on strictadherence to specific procedural steps. It is assumed that allwho use this method will be trained analysts capable ofperforming common laboratory procedures skillfully andsafely, and that the work will be performed in a properlyequipped laboratory.5.3
28、It is expected that laboratories using this method willprepare their own work instructions. These work instructionswill include detailed operating instructions for the specificlaboratory, the specific reference materials employed, andperformance acceptance criteria.6. Recommended Analytical Lines an
29、d PotentialInterferences6.1 In Spark-AES or GD-AES atomic emission, whenpossible, select analytical lines which are free from spectralinterferences. However, this is not always possible, and it maybe necessary to apply background or inter-element correctionsto account mathematically for the effect o
30、f the interference onthe measured intensities. If interference corrections arenecessary, refer to Practice E305 for detailed information onthe various techniques used to calculate interference correc-tions.6.2 Table 1 lists analytical lines routinely used for analysisof titanium alloys. For consiste
31、ncy of expression, the wave-lengths are all listed as stated in the National Institute ofStandards and Technology (NIST) Atomic Spectroscopy Data-base. In the NIST wavelength table, wavelengths 200 nm areas determined in a vacuum and wavelengths 200 nm are asdetermined in air. Potential spectral int
32、erferences are alsoindicated. It is not implied that measurements for this standardtest method must be made under the analytical conditions usedby NIST. Refer to Section 7 for a discussion of appropriatespectrometer configurations.7. Apparatus7.1 Excitation Source:3Available from American National S
33、tandards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.E2994 1627.1.1 Spark Source, unipolar, triggered capacitor discharge.In todays instrumentation, the excitation source is computercontrolled and is normally programmed to produce: (1) ahigh-energy pre-spark (o
34、f some preset duration), (2) a spark-type discharge (of some preset duration), (3) an arc typedischarge (of some preset duration), and (4) a spark-typedischarge, during which, time resolved measurements are madefor improved detection limits, (this may be optional on someinstruments).7.1.2 Glow Disch
35、arge Source, capable of producing anargon plasma discharge. With current instrumentation, theexcitation source may be direct current (DC) or radio fre-quency (RF) based.7.2 Gas Flow SystemDesigned to deliver pure argon gasto the excitation/sample interface region. Use the minimumargon purity specifi
36、ed by the instrument manufacturer. Refer toPractice E406 for practical guidance on the use of controlledatmospheres.7.3 SpectrometerHaving acceptable dispersion,resolution, and wavelength coverage for the determination oftitanium alloys. As described in Guide E1507.7.4 Optional Optical Path Purge or
37、 Vacuum SystemDesigned to enhance vacuum wavelength sensitivity by eitherpurging the optical path with a UV-transparent gas or byevacuating the optical path to remove air. The UV-transparentgas must meet the manufacturers minimum suggested purityrequirements.7.5 Measuring and Control SystemsDesigned
38、 to convertemitted light intensities to a measureable electrical signal.These systems will consist of either a series of photomultipliertubes (PMT) or solid-state photosensitive arrays (ChargeCoupled Device (CCD) or Charge Injection Device (CID) andintegrating electronics.Adedicated computer is used
39、 to controlanalytical method conditions, source operation, dataacquisition, and the conversion of intensity data to massfraction.7.6 Other SoftwareDesigned to coordinate instrumentfunction. At a minimum, the instruments software shouldinclude functions for calibration, routine instrument drift cor-r
40、ection (standardization) and routine analysis. Additional soft-ware features may include functionality for tasks such ascontrol charting.7.7 Specimen Preparation Equipment:7.7.1 Lathe, capable of machining a smooth, flat surface onthe reference materials and samples. A variable speed cutter, acement
41、ed carbide or polycrystalline diamond tool bit, and anautomatic cross-feed are highly recommended.7.7.2 Milling Machine, a milling machine can be used as analternative to a lathe.7.7.3 Belt/Disk Sanding, a belt sander may be used toprepare the surface for analysis.NOTE 1Spectrometer manufacturers ma
42、y have specific specimenpreparation guidelines which may influence the selection of specimenpreparation equipment.8. Reagents and Materials8.1 Reference Materials:8.1.1 Certified reference materials (CRMs) should be usedas calibration reference materials, if available. These certifiedreference mater
43、ials shall be of similar composition to the alloysbeing analyzed. In cases where CRMs are not available for theelement and/or alloy being analyzed or if available CRMs donot adequately cover the intended analytical range, it isacceptable to use other reference materials for calibration.8.2 Other Ref
44、erence Materials:TABLE 1 Analytical Lines for the Analysis of Titanium Alloys andPotential InterferencesElementsWavelength, (nm)Potential Interferences, (nm)Aluminum 236.70256.799 Zr 256.764394.401396.152Boron 182.64208.957249.678 Fe 249.678Carbon 165.701165.812193.027 Al 193.041Chromium 284.325 Zr
45、284.352425.433Copper 200.3327.396510.554Iron 371.993259.940 Ti 259.992259.957Manganese 403.076403.307403.449Molybdenum 386.411 Zr 386.387Nickel 341.476 Zr 341.466231.604Niobium 316.34 W 316.342319.50405.89Nitrogen 149.26174.272Oxygen 130.22Palladium 340.458 Mo 340.434, Zr 340.483363.470Ruthenium 349
46、.894372.803Silicon 212.415251.611288.158 Cr 288.123Tin 147.5189.989303.41317.505 Fe 317.544Titanium 337.279367.16374.16Tungsten 239.71429.461 Zr 429.479Vanadium 214.01326.770411.179 W 411.182437.924 Zr 437.978Yttrium 360.073 Zr 360.119371.029 Ti 370.996Zirconium 339.198 Fe 339.23, Nb 339.234343.8233
47、57.247 Fe 357.200, W 357.240360.119 Cr 360.167E2994 1638.2.1 In-House Reference MaterialsSome laboratoriesmay have the resources to produce in-house reference materialsfor titanium alloys. It is acceptable to use these referencematerials for calibration of Spark-AES and GD-AES instru-ments provided
48、that the in-house reference materials have beendeveloped following technically sound development protocolsand are accompanied with appropriate documentation. Refer toguide E2972 Standard Guide for Production, Testing, andValueAssignment of In-House Reference Materials for Metals,Ores, and Other Rela
49、ted Materials.8.3 Instrument Manufacturer Provided ReferenceMaterialsSome manufacturers perform factory calibrationswhich may include reference materials owned by the manu-facturer. The laboratory should make reasonable attempts tosecure certificates of analysis for each of these referencematerials and to evaluate the acceptability of these certificatesin conjunction with the laboratorys quality policies.8.4 Drift Correction (standardization) MaterialsThissuite of materials should be of similar composition to the alloysbeing analyzed and should contain a
