ASTM E2824-2018 Standard Test Method for Determination of Beryllium in Copper-Beryllium Alloys by Phosphate Gravimetric Method.pdf

1、Designation: E2824 18Standard Test Method forDetermination of Beryllium in Copper-Beryllium Alloys byPhosphate Gravimetric Method1This standard is issued under the fixed designation E2824; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi

2、sion, 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 determination of beryl-lium in copper-beryllium alloys in percentages

3、 from 0.1 % to3.0 % by the phosphate gravimetric method.1.2 UnitsThe values stated in SI units are to be regardedas standard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is the

4、responsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Section 9.1.4 This international standard was developed in accor-dance wit

5、h internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards

6、:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Rela

7、ted MaterialsE173 Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals (Withdrawn1998)3E255 Practice for Sampling Copper and Copper Alloys forthe Determination of Chemical CompositionE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performanc

8、e of an Analytical Method3. Terminology3.1 For definitions of terms used in this method, refer toTerminology E135.4. Summary of Test Method4.1 Beryllium is precipitated as the phosphate, which isfiltered, ignited, and weighed as beryllium pyrophosphate.Interfering elements, if present, may be comple

9、xed with(ethylenedinitrilo) tetraacetate solution.5. Significance and Use5.1 This test method is primarily intended to test suchmaterials for compliance with compositional specifications. Itis assumed that all who use these test methods will be trainedanalysts capable of performing common laboratory

10、 proceduresskillfully and safely. It is expected that work will be performedin a properly equipped laboratory.6. Interferences6.1 The elements ordinarily present in beryllium-copperalloys do not interfere.7. Apparatus7.1 Electrodes for ElectroanalysisRecommended station-ary type platinum electrodes

11、are described in 7.1.1 and 7.1.2.The surface of the platinum electrode should be smooth, clean,and bright to promote uniform deposition and good adherence.Deviations from the exact size and shape are allowable. Ininstances where it is desirable to decrease the time ofdeposition, a generally availabl

12、e rotating type of electrode maybe employed. Cleaning of the electrode by sandblasting is notrecommended.1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is the directresponsibility of Subcommittee E01.05 on Cu, Pb,

13、Zn, Cd, Sn, Be, Precious Metals,their Alloys, and Related Metals.Current edition approved April 15, 2018. Published June 2018. Originallyapproved in 2011. Last previous edition approved in 2011 as E282411. DOI:10.1520/E2824-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orc

14、ontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Driv

15、e, PO Box C700, West Conshohocken, 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 iss

16、ued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.17.1.1 CathodesPlatinum cathodes may be either open orclosed cylinders formed from sheets that are plain orperforated, or from gauze. Gauze cathodes are recommended;preferably from 50-mesh gauze woven from approximately0

17、.21 mm diameter wire. The top and bottom of gauze cathodesshould be reinforced by doubling the gauze about 3 mm ontoitself, or by the use of platinum bands or rings. The cylindershould be approximately 30 mm in diameter and 50 mm inheight. The stem should be made from a platinum alloy wiresuch as pl

18、atinum-iridium, platinum-rhodium, or platinum-ruthenium, having a diameter of approximately 1.3 mm. Itshould be flattened and welded the entire length of the gauze.The overall height of the cathode should be approximately 130mm. A cathode of these dimensions will have a surface area of135 cm2exclusi

19、ve of the stem.7.1.2 AnodesPlatinum anodes may be a spiral type whenanodic deposits are not being determined, or if the deposits aresmall. Spiral anodes should be made from 1.0 mm or largerplatinum wire formed into a spiral of seven turns having aheight of approximately 130 mm. A spiral anode of the

20、sedimensions will have a surface area of 9 cm2. When bothcathode and anode plates are to be determined, the anodeshould be made of the same material and design as theelectrode described in 7.1.1. The anode cylinder should beapproximately 12 mm in diameter and 50 mm in height and theoverall height of

21、 the anode should be approximately 130 mm.A gauze anode of these dimensions will have a surface area of54 cm2exclusive of the stem.8. Reagents8.1 Ammonium Acetate Solution (500 g/L)Dissolve 500 gof ammonium acetate in water, and dilute to 1 L.8.2 Ammonium Acetate Wash SolutionDilute 5 mL of theammon

22、ium acetate solution to 1 L, and adjust the pH to 5.2 60.05 with acetic acid. Use a pH meter for all pH adjustments.8.3 Ammonium Dihydrogen Phosphate (100 g/L)Dissolve100 g of ammonium dihydrogen phosphate (NH4H2PO4)inwater and dilute to 1 L.8.4 Ammonium (Ethylenedinitrilo) Tetraacetate Solution(28

23、g/L)To 2.5 g of (ethylenedinitrilo) tetraacetic acid add 30mL of water and a drop of methyl red solution. Neutralize withNH4OH (1 + 1), and warm gently to dissolve the last traces ofsolid. Cool and dilute to 100 mL.8.5 Methyl Red Indicator Solution (0.5 g/L ethanol)Dissolve 0.05 g of methyl red in 1

24、00 mL of ethanol.8.6 Sulfuric-Nitric Acid MixtureAdd slowly, while stirringin a cold water bath, 300 mL of H2SO4to 750 mL of water.Cool and add 210 mL of HNO3.9. Hazards9.1 For precautions to be observed in this test method, referto Practices E50. Both beryllium metal and its compounds maybe toxic.

25、Exercise care to prevent contact of beryllium-containing materials with the skin. The inhalation of anyberyllium-containing substance, either as a volatile compoundor as finely divided powder, should be especially avoided.Beryllium-containing residues (especially ignited oxide)should be carefully di

26、sposed.10. Sampling10.1 Sampling shall conform to Practice E255. However,this method does not supersede any sampling requirementsspecified in a specific ASTM material specification.11. Rounding Calculated Values11.1 Rounding of test results obtained using this testmethod shall be performed in accord

27、ance with Practice E29,Rounding Method, unless an alternative rounding method isspecified by the customer or applicable material specification.12. Preparation of Apparatus12.1 CathodeClean the cathode in hot HNO3, (1 + 1),rinse with distilled water, rinse in two separate baths of ethanolor acetone.

28、Dry at a low temperature, (110 C for 3 to 5 min),and cool to room temperature in a desiccator.12.2 AnodeClean in HCl, (1 + 1), rinse with distilledwater.12.3 Weigh the cathode to the nearest 0.1 mg and record theweight. The anode does not have to be weighed.13. Procedure13.1 Transfer 5.00 g of sampl

29、e to a 300-mL electrolysisbeaker. Add 42 mL of the H2SO4-HNO3mixture, cover, andallow to stand a few minutes until the reaction has nearlyceased. Heat at 80 C to 90 C until dissolution is complete andbrown fumes have been expelled. Wash down the cover glassand the sides of the beaker and dilute to a

30、bout 175 mL (enoughto submerge the cathode when it is inserted).13.2 Insert the electrodes, cover the solution with a pair ofsplit watch glasses, and electrolyze at a current density of 0.6A/dm2for about 16 h. Wash down the cover glasses, sides ofthe beaker, and electrode stems and continue electrol

31、ysis forabout 15 min. If no copper plates on the newly exposedcathode surface, copper deposition may be considered com-pleted.13.3 Quickly withdraw the cathode from the electrolytewhile directing a gentle stream of water from a wash bottleover its surface.13.4 Evaporate the spent electrolyte to dens

32、e white fumesand fume for about 5 min to dehydrate the silicic acid. Cool,add about 50 mL of water, and heat until all salts are insolution. Filter through a small, medium-texture paper, catch-ing the filtrate in a 250-mL volumetric flask. Wash the beakerand paper thoroughly with hot H2SO4(1 + 99),

33、combining thewashings with the filtrate. Cool the solution in the volumetricflask, dilute to the mark, and mix.13.5 Using a pipet, transfer 50 mL of the solution in 13.4 toa 400-mL beaker. Add 3 drops of HF and 10 mL of H2SO4(1+ 2), and evaporate to fumes. Cool to room temperature andadd 100 mL of w

34、ater. Heat to dissolve soluble salts and againcool to room temperature.E2824 18213.6 Add 10 mL of ammonium (ethylenedinitrilo) tetraac-etate solution, and adjust the pH to 2.0 6 0.05 (see 8.2 for allpH adjustments) with NH4OH (1 + 1). Boil 1 min and cool toroom temperature. Add 10 mL of ammonium dih

35、ydrogenphosphate solution and adjust the pH to 5.2 6 0.05 withammonium acetate solution.13.7 Heat to boiling cautiously to prevent bumping, andthen maintain just below the boiling point until the precipitatebecomes granular. Remove from the source of heat and allowto stand at least 12 h.13.8 Filter

36、using an 11-cm fine paper and wash six timeswith ammonium acetate wash solution. Discard the filtrate.Dissolve the precipitate with 100 mL of hot HCl (1 + 4),collecting the solution in the original beaker.13.9 Add 2 mL of ammonium (ethylenedinitrilo) tetraac-etate solution, and adjust the pH to 2.0

37、6 0.05 with NH4OH(1 + 1). Cool, add 2 mL of ammonium dihydrogen phosphatesolution, and adjust the pH to 5.2 6 0.05 with ammoniumacetate solution. Proceed as directed in 13.7.13.10 Filter using an 11-cm fine paper and wash six timeswith ammonium acetate wash solution. Transfer the paper to aweighed p

38、latinum crucible. Place the crucible in a mufflefurnace, and dry and char the paper by gradually increasing thetemperature to 500 C. When all the carbon has been removed,raise the temperature to 1000 C and maintain at this tempera-ture for 4 h. Cool in a desiccator and weigh.14. Calculation14.1 Calc

39、ulate the percentage of beryllium as follows:Beryllium, % 5 A 30.0939/B! 3100 (1)where:A = grams of beryllium pyrophosphate, andB = grams of sample used.15. Precision and Bias15.1 PrecisionEight laboratories cooperated in testing thismethod and obtained the data summarized in Table 1.15.2 BiasNo cer

40、tified reference materials suitable fortesting this test method were available when the interlaboratorytesting program was conducted. The user of this standard isencouraged to employ accepted reference materials, ifavailable, to determine the accuracy of this test method asapplied in a specific labo

41、ratory.15.3 This test method was evaluated in accordance withPractice E173 (discontinued 1997). Practice E173 has beenreplaced by Practice E1601. The Reproducibility R2of PracticeE173 corresponds to the Reproducibility Index R of PracticeE1601. The Repeatability R1of Practice E173 corresponds tothe

42、Repeatability Index r of Practice E1601.16. Keywords16.1 beryllium; copper-beryllium alloys; gravimetricASTM 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

43、determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapprove

44、d or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel

45、 that your comments have not received a fair hearing you shouldmake your views known 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 repri

46、nts (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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Statistical InformationTest SpecimenBerylliumFound,%Repeatability(R1, E173)Reproducibility(R2, E173)(1) Beryllium copper, B-7 1.744 0.026 0.042(2) Beryllium copper, C-7 0.460 0.020 0.046E2824 183