ASTM E2626-2008 Standard Guide for Spectrometric Analysis of Reactive and Refractory Metals.pdf

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1、Designation: E 2626 08Standard Guide forSpectrometric Analysis of Reactive and Refractory Metals1This standard is issued under the fixed designation E 2626; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.

2、 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 guide covers a variety of analytical techniques thathave proven to be acceptable for the analysis of the reactiveand refractory

3、 metals titanium, zirconium, niobium, hafnium,tantalum, molybdenum, tungsten, and vanadium.1.2 The principles and techniques in this guide can be usedby ISO 17025 compliant laboratories that need to implementother performance-based test methods or need to document andvalidate extensions of standard

4、test methods, or non-standardtest methods.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 practices and determine the applica-bility of regulator

5、y limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE 135 Terminology Relating to Analytical Chemistry forMetals, Ores,

6、 and Related MaterialsE 539 Test Method for X-Ray Fluorescence SpectrometricAnalysis of 6Al-4V Titanium AlloyE 882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE 1097 Guide for Direct Current Plasma-Atomic EmissionSpectrometry AnalysisE 1184 Practice for Electrother

7、mal (Graphite Furnace)Atomic Absorption AnalysisE 1479 Practice for Describing and Specifying Inductively-Coupled Plasma Atomic Emission SpectrometersE 1552 Test Method for Determining Hafnium in Zirco-nium and Zirconium Alloys Using the D-C Argon PlasmaSpectrometerE 1621 Guide for X-Ray Emission Sp

8、ectrometric AnalysisE 1770 Practice for Optimization of Electrothermal AtomicAbsorption Spectrometric EquipmentE 2371 Test Method for Analysis of Titanium and TitaniumAlloys by Atomic Emission Plasma SpectrometryE 2437 Practice for Designing and Validating Performance-Based Test Methods for the Anal

9、ysis of Metals, Ores, andRelated MaterialsE 2438 Practice for Implementing Standard PerformanceBased Test Methods for the Analysis of Metals, Ores, andRelated Materials2.2 ISO Standards:3ISO 17025 General Requirements for the Competence ofTesting and Calibration LaboratoriesISO Guide 32 Calibration

10、in Analytical Chemistry and Useof Certified Reference Materials3. Terminology3.1 DefinitionsFor definitions of terms used in this guide,refer to Terminology E 135.3.2 Definitions of Terms Specific to This Standard:3.2.1 reactive metal, na metal, such as titanium or zirco-nium, that readily reacts wi

11、th the environment. It has a strongaffinity for oxygen and nitrogen and forms very stable com-pounds that passivate in thin layers. When the reactive coatingis damaged, it self heals by reaction with the atmosphere.3.2.2 refractory metal, na metal, such as hafnium, molyb-denum, niobium, tantalum, va

12、nadium, or tungsten, character-ized by very high melting points, above about 1900 C, thatoxidizes at temperatures far below its melting point.4. Significance and Use4.1 Test methods for chemical analysis of reactive andrefractory metals are primarily intended to test such materialsfor compliance wit

13、h compositional specifications. It is assumedthat all who use this guide will be trained analysts capable ofperforming common laboratory procedures skillfully andsafely. It is expected that work will be performed in a properlyequipped laboratory under appropriate quality control practicessuch as tho

14、se described in Guide E 882 and Practice E 2437,aswell as in ISO 17025 and ISO Guide 32.1This guide is under the jurisdiction of ASTM Committee E01 on AnalyticalChemistry for Metals, Ores and Related Materials and is the direct responsibility ofSubcommittee E01.06 on Ti, Zr, W, Mo, Ta, Nb, Hf, Re.Cu

15、rrent edition approved June 15, 2008. Published July 2008.2For 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.3Av

16、ailable from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 This guide is intended to aid analytical chemistrylaborat

17、ories in the analysis of reactive and refractory metalsand their alloys when no specific standard test methods areavailable. The principles incorporated in this practice can alsobe applied in laboratories that wish to validate and documentnon-standard test methods.4.3 The analysis of reactive and re

18、fractory materials istypically performed by only a small number of laboratories.Few of these laboratories have analytical instrumentation incommon for use in interlaboratory proficiency testing pro-grams. This requires the use of within-laboratory developedtest methods that vary between laboratories

19、. It is intended thatthis practice will give general guidance to experienced person-nel that will assist them in the development of a procedure thatwill meet their analytical objectives.4.4 Practice E 2438 provides guidance for the developmentand documentation of an In-House Standard Operating Proce

20、-dure (SOP).5. Hazards5.1 The dissolution of these metals usually requires the useof hydrofluoric acid. Read and follow label precautions andmandatory safety data sheet (MSDS) information, and refer toPractices E50.5.2 Fine turnings, chips, or powder require more water tomoderate the reaction rate.

21、If the metal is solid chunks ratherthan finely divided, the dissolution will be much slower andrequire less water. It will also require additional acid tocomplete the dissolution. See Specification D 1193 for reagentwater specifications.5.3 Fine turnings or powder of hafnium, titanium, andzirconium

22、are pyrophoric. Observe the proper precautions.6. Test Methods6.1 Atomic Absorption Spectrometry (AAS)This techniqueis applicable to elements that can be dissolved and placed in thevapor state (flame or flameless) as ground state atoms. Radia-tion from a hollow cathode light source emits the spectru

23、m ofthe element to be analyzed, which is then passed through vaporcontaining the element to be analyzed, and into a monochro-mator set for radiation characteristic of the element. The degreeof absorption is measured, and is proportional to the amount ofthe particular element present.Analysis is made

24、 by comparisonto reference materials. Lists of elements that can be deter-mined, sensitivities, wavelengths, and operating parameters areprovided by the instrument manufacturers. Due to the require-ments of the materials specifications, the AAS detection limitsfor many elements will not be low enoug

25、h for the use of thistechnique. AAS has been utilized for the analysis of iron,chromium, nickel, and tin in zirconium alloys and for thedetermination of iron and zirconium in hafnium. PracticesE 1184 and E 1770 provide further details.6.2 Atomic Emission Spectrometry (AES)This techniquehas historica

26、lly been the main means of analysis for thesemetals. Analysis by the techniques described in this section isbased upon the fact that each vaporized element, when suitablyexcited by an arc, spark, plasma, or other means, is made toemit its characteristic spectrum. The radiation thus emittedpasses int

27、o a spectrometer where it is resolved into itscomponent wavelengths and recorded by various means as adefinite pattern. The position of the spectral informationindicates QUALITATIVELY which elements are present. Theintensity determines QUANTITATIVELY the amount of eachelement in the sample when comp

28、ared to intensities obtainedby using calibration materials. Calibration materials can bereference materials or industry acceptable analyzed specimens.6.2.1 Arc/Spark Spectrometry (AS-AES)Instruments uti-lizing photographic film or plates were the mainstay for manyyears until parts and supplies becam

29、e very difficult, if notimpossible, to obtain. Electronic read-out arc/spark instrumentsare still used by a number of laboratories. The primary problemwith arc/spark is the unavailability of solid reference materialsfor calibration. Metallurgical history and surface grain sizeeffects can become an i

30、ssue. However, if proper calibrationmaterials were available, the majority of the necessary ele-ments in a typical material specification could be analyzed.6.2.2 Direct Current Plasma Atomic Emission Spectrometry(DCP-AES)Since DCP-AES analysis, like atomic absorp-tion, Inductively Coupled Plasma Ato

31、mic Emission Spectrom-etry (ICP-AES) (see 6.2.3), and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) (see 6.2.4), relies on sampledissolution, the major difficulties with reference materials forcalibration with can be overcome by the techniques discussedin 9.4. One of the main positive attrib

32、utes of this technique isthe high resolution available due to the Echelle grating. Thehighly complex spectra of reactive and refractory metalsrequire an instrument with good spectral resolving power inorder to find interference-free wavelengths. The DCP-AES hasa rugged sample introduction system tha

33、t lends itself well tothe analysis of materials that have been dissolved in acids suchas hydrofluoric, nitric, and hydrochloric acids. In most cases,due to the nature of the source design, the DCP-AES does notachieve the detection limits or the precision of an InductivelyCoupled Plasma (ICP) source.

34、 In some cases, however, itssignificantly superior resolving power may allow it to out-perform an ICP that utilizes a conventional ruled grating. Thecorrosion resistant nature of the sample introduction systemand jet materials on DCP-AES has allowed it to be verycapable for the analysis of silicon i

35、n a hydrofluoric acidsolution. DCP-AES is unable to achieve the necessary detec-tion limits for elements such as boron and cadmium in azirconium sample at the levels required by most specifications.Test Method E 1552 gives details for the analysis of hafnium inzirconium and zirconium alloys using th

36、e DCP-AES techniqueand Test Method E 2371 describes the analysis of titanium andtitanium alloys. Guide E 1097 discusses the technique in moregeneral terms.6.2.3 Inductively Coupled Plasma Atomic Emission Spec-trometry (ICP-AES)Practice E 1479 describes the compo-nents of an ICP-AES that are basic to

37、 its operation and to thequality of its performance. ICP-AES and ICP-MS represent theinstruments most commonly used for the analysis of reactiveand refractory metals. These solution-based techniquescomplement each other to provide a reliable means of analysisof reactive and refractory metals. Care m

38、ust always be taken toavoid serious spectral interferences due to the line-rich natureof reactive and refractory metals. The advent of solid-stateE2626082detectors has provided much flexibility in the selection ofwavelengths. Section 8.3 gives guidance in wavelength selec-tion. Test Method E 2371 gi

39、ves details for the analysis oftitanium and titanium alloys, while Practice E 1479 discussesthe techniques in more general terms.6.2.4 Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)This technique is distinguished from ICP-AES by thedetection system used to analyze the species excited by aplas

40、ma. A mass spectrometer is utilized in this case. Much ofthe information in Practice E 1479 is applicable to ICP-MS.This technique is capable of analyzing the majority of the metalelements necessary to satisfy the material specifications forreactive and refractory metals. The high sensitivity of ICP

41、-MSmay require significant dilution of the sample solution in orderto analyze elements at concentrations above 0.1 %, by mass.6.3 Glow Discharge SpectrometryThe issue mentionedabove in securing solid reference materials is a concern thatmust be addressed with this technique. Glow Discharge instru-me

42、ntation is normally divided into two types of instrumenta-tion.6.3.1 Glow Discharge-Mass Spectrometry (GD-MS)Inthis technique, the surface of a solid sample is sputtered withargon gas. Ionized species are then subjected to high-resolutionmass spectrometric analysis. This results in the high sensitiv

43、ityanalysis of all elements in the periodic table, except hydrogenat the trace level. GD-MS has been used for the multi-elementsurvey analysis for these metals included in the scope of thisguide. Care must be taken in the interpretation of the results,however, due to the non-homogeneity of the sampl

44、e surface.Reactive and refractory metals typically exhibit a relativelylarge grain size compared to the small area sampled by theconventional “pin” sample used by the GD-MS. It is alsopossible to sample a flat surface, which may help alleviate thegrain size problem. One should keep in mind that only

45、 a fewhundred micrograms of material are sampled, which under-scores the importance of homogeneity. Due to the high cost andcomplexity of the instrumentation, GD-MS is found in veryfew captive laboratories. Commercial analysis is availablethrough a limited number of laboratories.6.3.2 Glow Discharge

46、 Atomic Emission Spectrometry (GD-AES)The glow discharge excitation source is a device thatproduces luminous plasma. Solid samples are sputtered usingthe low-pressure argon plasma. The argon ions etch atoms andsmall atomic clusters from the sample surface making themavailable for dissociation and ex

47、citation in the plasma. Metal-lurgical history is reduced because sampling and excitationtake place in separate locations. Calibration requires the use ofreference materials and where available it is possible todetermine the alloying and minor constituents simultaneously.6.4 X-ray Emission Spectrome

48、try (XRF)See GuideE 1621 for details of the instrumentation. Again, the require-ment for a set of homogeneous, solid reference materials limitsthe use of this technique. The low detection limit requirementsfor many of the required elements in these materials will not beachieved by this technique. Th

49、e analysis of iron, chromium,nickel, and tin in zirconium alloys and zirconium in hafniumhave been demonstrated to work well by X-ray. Test MethodE 539 and Guide E 1621 give valuable guidance.7. Calibration7.1 Set up the instrument for calibration as recommended bythe manufacturer. The publications listed in Section 2, as wellas in texts, the analytical literature, and other standardsorganizations, will also provide valuable guidance.8. Interferences8.1 Guide E 1097, Practice E 1184, Practice E 1479, GuideE 1621, and Practice E 1770 describe some of the interferencesenco