1、Designation:E 121 83(Reapproved 2004)Standard Test Methods forChemical Analysis of Copper-Tellurium Alloys1This standard is issued under the fixed designation E 121;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last rev
2、ision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover procedures for the chemicalanalysis of copper-tellurium alloys having chemical composi-tions within the f
3、ollowing limits:Copper,A%98 and overTellurium,%0.04 to 0.6AIncludes silver.1.2 The analytical procedures appear in the following order:SectionsCopper by the Electrolytic Method8 to 12Tellurium by the Dichromate(Volumetric)Method13 to 172.Referenced Documents2.1 ASTM Standards:2E 29 Practice for Usin
4、g Significant Digits in Test Data toDetermine Conformance With SpecificationsE 50 Practices for Apparatus,Reagents,and Safety Precau-tions for Chemical Analysis of MetalsE 55 Practice for Sampling Wrought Nonferrous Metals andAlloys for Determination of Chemical Composition3.Significance and Use3.1
5、These test methods for the chemical analysis of metalsand alloys are primarily intended to test such materials forcompliance with compositional specifications.It is assumedthat all who use these test methods will be trained analystscapable of performing common laboratory procedures skill-fully and s
6、afely.It is expected that work will be performed ina properly equipped laboratory.4.Apparatus and Reagents4.1 Apparatus and reagents required for each determinationare listed in separate sections preceding the procedure.Theapparatus,standard solutions,and certain other reagents usedin more than one
7、procedure are referred to by number and shallconform to the requirements prescribed in Practices E 50.5.Precautions5.1 For precautions to be observed in these test methods,reference shall be made to Practices E 50.6.Sampling6.1 Sampling shall conform to Practice E 55.7.Rounding Calculated Values7.1
8、Calculated values shall be rounded to the desired num-ber of places in accordance with the rounding method given in3.4 and 3.5 of Practice E 29.COPPER BY THE ELECTROLYTIC TEST METHOD8.Summary of Test Method8.1 Copper is deposited electrolytically on a platinum cath-ode.The addition of manganese nitr
9、ate to the electrolyteprevents the deposition of tellurium.9.Apparatus9.1 Electrodes for ElectroanalysisApparatus No.9.10.Reagents10.1 Manganese Nitrate Solution(20 g/L)Dilute 4 mL ofthe commercially available Mn(NO3)2solution(50%)to 100mL with water.10.2 Potassium Permanganate Solution(20 g/L)Disso
10、lve2 g of KMnO4in water and dilute to 100 mL.10.3 Sulfuric-Nitric Acid MixtureAdd slowly,while stir-ring,300 mL of H2SO4to 750 mL of water.Cool and add 210mL of HNO3.11.Procedure11.1 Transfer 2.00 g of the sample to a 300-mL electrolysisbeaker.Add 30 mL of H2SO4-HNO3mixture,cover,and allowto stand a
11、 few minutes until reaction has nearly ceased.Heat at80 to 90C until dissolution is complete and brown fumes havebeen expelled.Wash down the cover glass and the sides of thebeaker and dilute to about 200 mL.Add KMnO4solution1These test methods are under the jurisdiction of ASTM Committee E01 onAnaly
12、tical Chemistry for Metals,Ores,and Related Materials and are the directresponsibility of Subcommittee E01.05 on Cu,Pb,Zn,Cd,Sn,Be,their Alloys andRelated Metals.Current edition approved June 1,2004.Published August 2004.Originallyapproved in 1956.Last previous edition approved in 1996 as E 121 83(1
13、996).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.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C7
14、00,West Conshohocken,PA 19428-2959,United States.dropwise until a faint,permanent pink color is produced andthen add 5 mL of Mn(NO3)2solution.11.2 Insert the electrodes,cover the solution with a pair ofsplit watch glasses,and electrolyze at a current density of about0.6 A/dm2for about 16 h or at a c
15、urrent density of 4 A/dm2forabout 2.5 h.Wash down the cover glasses,the sides of thebeaker,and the electrode stems,and continue electrolysis forabout 15 min.If no copper plates on the newly exposedcathode surface,copper deposition may be considered com-pleted.11.3 Quickly withdraw the cathode from t
16、he electrolytewhile directing a gentle stream of water from a wash bottleover its surface.Rinse the cathode in a water bath and then dipin two successive baths of ethanol or acetone.Dry in an ovenat 110C for 3 to 5 min,cool,and weigh.11.4 Strip the copper deposit from the cathode by immer-sion in HNO3(1+1)for a few minutes.When dissolution of thecopper is complete,rinse the cathode in a water bath and thendip in two successive baths of ethanol or acetone.Dry in anoven at 110C for 3 to 5 min,cool
