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

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1、Designation: E2824 18aStandard Test Method forDetermination of Beryllium in Copper-Beryllium Alloys byPhosphate Gravimetry1This standard is issued under the fixed designation E2824; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t

2、he 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 from 0

3、.1 % to3.0 % by phosphate gravimetry.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 theresponsibility of t

4、he 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 with internationally r

5、ecognized 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:2E29 Practice for

6、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 Related MaterialsE173 P

7、ractice 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 Performance of an Analytical

8、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 complexed with(ethylenedi

9、nitrilo) tetraacetate solution.5. Significance and Use5.1 This test method for the chemical analysis of metals andalloys is primarily intended to test such materials for compli-ance with compositional specifications. It is assumed that allwho use these test methods will be trained analysts capable o

10、fperforming common laboratory procedures skillfully andsafely. It is expected that work will be performed in a properlyequipped laboratory.6. Interferences6.1 The elements ordinarily present in beryllium-copperalloys do not interfere.7. Apparatus7.1 Electrodes for ElectroanalysisRecommended station-

11、ary type platinum electrodes 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 of de

12、posi-tion and agitation of the electrolyte is permissible, a generally1This 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, Zn, Cd, Sn, Be, Precious Metals,the

13、ir Alloys, and Related Metals.Current edition approved June 1, 2018. Published July 2018. Originally approvedin 2011. Last previous edition approved in 2018 as E282418. DOI: 10.1520/E2824-18A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser

14、viceastm.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 Drive, PO Box C700, West Conshohocken,

15、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 Organization

16、 Technical Barriers to Trade (TBT) Committee.1available rotating type of electrode may be employed. Cleaningof the electrode by sandblasting is not recommended.7.1.1 CathodesPlatinum cathodes may be either open orclosed cylinders formed from sheets that are plain orperforated, or from gauze. Gauze c

17、athodes are recommended;preferably from 50-mesh gauze woven from approximately0.21 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 a

18、nd 50 mm inheight. The stem should be made from a platinum alloy wiresuch as platinum-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

19、 130mm. A cathode of these dimensions will have a surface area of135 cm2exclusive of the stem.7.1.2 AnodesPlatinum anodes may be a spiral type whenanodic deposits are not being determined, or if the deposits aresmall (as in the electrolytic determination of lead when it ispresent in concentrations b

20、elow 0.2 %). Spiral anodes shouldbe made from 1.0 mm or larger platinum wire formed into aspiral of seven turns having a height of approximately 130 mm.A spiral anode of these dimensions will have a surface area of9cm2. When both cathode and anode plates are to bedetermined, the anode should be made

21、 of the same material anddesign as the electrode described in 7.1.1. The anode cylindershould be approximately 12 mm in diameter and 50 mm inheight and the overall height of the anode should be approxi-mately 130 mm. A gauze anode of these dimensions will havea surface area of 54 cm2exclusive of the

22、 stem.7.1.3 Gauze cathodes are recommended where rapid elec-trolysis is used.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 theammonium acetate solution to 1 L, and adjust the pH to 5.2

23、60.05 with acetic acid.NOTE 1Use 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 g/L)To 2.5 g of (ethylenedinitrilo) tetraacetic a

24、cid 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 100 mL of ethanol.8.6 Sulfuric-Nitric Acid Mixture

25、Add 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 method, referenceshall be made to Practices E50. Both beryllium metal and itscompounds may be toxic. Care should be exercised to preventc

26、ontact of beryllium-containing materials with the skin. Theinhalation of any beryllium-containing substance, either as avolatile compound or as finely divided powder, should beespecially avoided. Beryllium-containing residues (especiallyignited oxide) should be carefully disposed.10. Sampling10.1 Sa

27、mpling 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 Calculated values shall be rounded to the desirednumber of places as directed in Practice E29.12. Preparation

28、of Apparatus12.1 CathodeClean the cathode in hot HNO3, (1 + 1),rinse with distilled water, rinse in two separate baths of ethanolor acetone. 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 W

29、eigh 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 sample 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

30、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 about 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 electroly

31、ze at a current density of 0.6A/dm2for about 16 h. Wash down the cover glasses, sides ofthe beaker, and electrode stems and continue electrolysis 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

32、 from the electrolytewhile directing a gentle stream of water from a wash bottleover its surface.13.4 Evaporate the spent electrolyte to dense 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 s

33、mall, medium-texture paper, catch-ing the filtrate in a 250-mL volumetric flask. Wash the beakerand paper thoroughly with hot H2SO4(1 + 99), 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 soluti

34、on 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 water. Heat to dissolve soluble salts and againcool to room temperature.E2824 18a213.6 Add 10 mL of ammonium (ethylenedinitrilo) tetraac-etate solution, and adj

35、ust the pH to 2.0 6 0.05 (see Note 1 forall pH adjustments) with NH4OH (1 + 1). Boil 1 min and coolto room temperature. Add 10 mL of ammonium dihydrogenphosphate solution and adjust the pH to 5.2 6 0.05 withammonium acetate solution.13.7 Heat to boiling cautiously to prevent bumping, andthen maintai

36、n 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 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 +

37、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 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 a

38、s 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 platinum crucible. Place the crucible in a mufflefurnace, and dry and char the paper by gradually increasing thetemperature to 500 C. When all the carbon ha

39、s 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 Calculate 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

40、. Precision and Bias15.1 PrecisionEight laboratories cooperated in testing thismethod and obtained the data summarized in Table 1.15.2 BiasNo certified reference materials suitable fortesting this test method were available when the interlaboratorytesting program was conducted. The user of this stan

41、dard isencouraged to employ accepted reference materials, ifavailable, to determine the accuracy of this test method asapplied in a specific laboratory.15.3 This test method was evaluated in accordance withPractice E173 (discontinued 1997). Practice E173 has beenreplaced by Practice E1601. The Repro

42、ducibility R2of PracticeE173 corresponds to the Reproducibility Index R of PracticeE1601. The Repeatability R1of Practice E173 corresponds tothe Repeatability Index r of Practice E1601.16. Keywords16.1 beryllium; copper-beryllium alloys; gravimetryASTM International takes no position respecting the

43、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 validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is

44、subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Head

45、quarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel 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 sta

46、ndard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (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 s

47、erviceastm.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 18a3