ASTM B954-07
(Test Method)Standard Test Method for Analysis of Magnesium and Magnesium Alloys by Atomic Emission Spectrometry
Standard Test Method for Analysis of Magnesium and Magnesium Alloys by Atomic Emission Spectrometry
SIGNIFICANCE AND USE
The metallurgical properties of magnesium and its alloys are highly dependant on chemical composition. Precise and accurate analyses are essential to obtaining desired properties, meeting customer specifications and helping to reduce scrap due to off-grade material.
This test method is applicable to chill cast specimens as defined in Practice B 953 and can also be applied to other types of samples provided that suitable reference materials are available.
SCOPE
1.1 This test method describes the analysis of magnesium and its alloys by atomic emission spectrometry. The magnesium specimen to be analyzed may be in the form of a chill cast disk, casting, sheet, plate, extrusion or some other wrought form or shape. The elements covered in the scope of this method are listed in the table below.Note 1
The concentration ranges given in the above scope are estimates based on two manufacturers observations and data provided by a supplier of atomic emission spectrometers. The range shown for each element does not demonstrate the actual usable analytical range for that element. The usable analytical range may be extended higher or lower based on individual instrument capability, spectral characteristics of the specific element wavelength being used and the availability of appropriate reference materials.
1.2 This test method is suitable primarily for the analysis of chill cast disks as defined in Sampling Practice B 953. Other forms may be analyzed, provided that: (1) they are sufficiently massive to prevent undue heating, (2) they allow machining to provide a clean, flat surface which creates a seal between the specimen and the spark stand, and (3) reference materials of a similar metallurgical condition (spectrochemical response) and chemical composition are available.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific safety and health statements are given in Section 10.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: B954 − 07
StandardTest Method for
Analysis of Magnesium and Magnesium Alloys by Atomic
Emission Spectrometry
This standard is issued under the fixed designation B954; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
specific element wavelength being used and the availability of appropriate
1. Scope
reference materials.
1.1 This test method describes the analysis of magnesium
1.2 This test method is suitable primarily for the analysis of
and its alloys by atomic emission spectrometry. The magne-
chill cast disks as defined in Sampling Practice B953. Other
siumspecimentobeanalyzedmaybeintheformofachillcast
forms may be analyzed, provided that: (1) they are sufficiently
disk, casting, sheet, plate, extrusion or some other wrought
massive to prevent undue heating, (2) they allow machining to
form or shape. The elements covered in the scope of this
provide a clean, flat surface which creates a seal between the
method are listed in the table below.
specimen and the spark stand, and (3) reference materials of a
Element Concentration Range (Wt %)
similar metallurgical condition (spectrochemical response) and
Aluminum 0.001 to 12.0
Beryllium 0.0001 to 0.01 chemical composition are available.
Boron 0.0001 to 0.01
1.3 This standard does not purport to address all of the
Cadmium 0.0001 to 0.05
Calcium 0.0005 to 0.05 safety concerns, if any, associated with its use. It is the
Cerium 0.01 to 3.0
responsibility of the user of this standard to establish appro-
Chromium 0.0002 to 0.005
priate safety and health practices and determine the applica-
Copper 0.001 to 0.05
Dysprosium 0.01 to 1.0
bility of regulatory limitations prior to use. Specific safety and
Erbium 0.01 to 1.0
health statements are given in Section 10.
Gadolinium 0.01 to 3.0
Iron 0.001 to 0.06
2. Referenced Documents
Lanthanum 0.01 to 1.5
Lead 0.005 to 0.1
2.1 ASTM Standards:
Lithium 0.001 to 0.05
Manganese 0.001 to 2.0 B953 Practice for Sampling Magnesium and Magnesium
Neodymium 0.01 to 3.0
Alloys for Spectrochemical Analysis
Nickel 0.0005 to 0.05
E135 Terminology Relating to Analytical Chemistry for
Phosphorus 0.0002 to 0.01
Metals, Ores, and Related Materials
Praseodymium 0.01 to 0.5
Samarium 0.01 to 1.0
E158 Practice for Fundamental Calculations to Convert
Silicon 0.002 to 5.0
Intensities into Concentrations in Optical Emission Spec-
Silver 0.001 to 0.2
trochemical Analysis (Withdrawn 2004)
Sodium 0.0005 to 0.01
Strontium 0.01 to 4.0
E172 Practice for Describing and Specifying the Excitation
Tin 0.002 to 0.05
SourceinEmissionSpectrochemicalAnalysis(Withdrawn
Titanium 0.001 to 0.02
Yttrium 0.02 to 7.0 2001)
Ytterbium 0.01 to 1.0
E305 Practice for Establishing and Controlling Atomic
Zinc 0.001 to 10.0
Emission Spectrochemical Analytical Curves
Zirconium 0.001 to 1.0
E406 Practice for Using Controlled Atmospheres in Spec-
NOTE 1—The concentration ranges given in the above scope are
trochemical Analysis
estimates based on two manufacturers observations and data provided by
E826 Practice for Testing Homogeneity of a Metal Lot or
a supplier of atomic emission spectrometers. The range shown for each
element does not demonstrate the actual usable analytical range for that Batch in Solid Form by Spark Atomic Emission Spec-
element. The usable analytical range may be extended higher or lower
trometry
based on individual instrument capability, spectral characteristics of the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction of ASTM Committee B07 on Light contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Metals and Alloys and is the direct responsibility of Subcommittee B07.04 on Standards volume information, refer to the standard’s Document Summary page on
Magnesium Alloy Cast and Wrought Products. the ASTM website.
Current edition approved June 1, 2007. Published June 2007. DOI: 10.1520/ The last approved version of this historical standard is referenced on
B0954-07. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B954 − 07
E876 Practice for Use of Statistics in the Evaluation of is a need to analyze almost the entire range of magnesium
Spectrometric Data (Withdrawn 2003) alloys. Because binary calibrants may respond differently from
E1257 Guide for Evaluating Grinding Materials Used for alloy calibrants, the latter are used to improve accuracy by
Surface Preparation in Spectrochemical Analysis applying a slope and/or intercept correction to the observed
E1329 Practice for Verification and Use of Control Charts in readings.
Spectrochemical Analysis 4.2.2 The second method, global calibration, employs cali-
E1507 Guide for Describing and Specifying the Spectrom- bration curves that are determined using many different alloy
eter of an Optical Emission Direct-Reading Instrument calibrants with a wide variety of compositions. Mathematical
calculations are used to correct for both alloy difference and
3. Terminology
inter-element effects. Like the method above, specific alloy
calibrants may be used to apply a slope and/or intercept
3.1 Definitions—For definitions of terms used in this
standard, refer to Terminology E135. correction to the observed readings.
4.2.3 The third method, alloy calibration, employs calibra-
3.2 Definitions of Terms Specific to This Standard:
tion curves that are determined using various alloy calibrants
3.2.1 binary type calibration—calibration curves deter-
that have similar matrix compositions. Again, specific alloy
mined using binary calibrants (primary magnesium to which
calibrants may be used to apply a slope and/or intercept
has been added one specific element).
correction to the observed readings.
3.2.2 global type calibration—calibration curves deter-
mined using calibrants from many different alloys with con-
5. Significance and Use
siderable compositional differences.
5.1 The metallurgical properties of magnesium and its
3.2.3 alloy type calibration—calibration curves determined
alloys are highly dependant on chemical composition. Precise
using calibrants from alloys with similar compositions.
and accurate analyses are essential to obtaining desired
3.2.4 two point drift correction—the practice of analyzing a properties, meeting customer specifications and helping to
high and low standardant for each calibration curve and reduce scrap due to off-grade material.
adjusting the counts or voltage values obtained back to the
5.2 This test method is applicable to chill cast specimens as
values obtained on those particular standardants during the
defined in Practice B953 and can also be applied to other types
collection of the calibration data. The corrections are accom-
of samples provided that suitable reference materials are
plished mathematically and are applied to both the slope and
available.
intercept. Improved precision may be obtained by using a
multi-point drift correction as described in Practice E1329.
6. Interferences
3.2.5 type standardization—mathematical adjustment of the
6.1 Table 1 lists analytical lines commonly used for mag-
calibration curve’s slope or intercept using a single standardant
nesium analysis. Other lines may be used if they give compa-
(reference material) at or close to the nominal composition for
rableresults.Alsolistedarerecommendedconcentrationrange,
the particular alloy being analyzed. For best results the
background equivalent concentration (BEC), detection limits,
standardant being used should be within 610 % of the com-
and potential interferences where available. The values given
position (for each respective element) of the material being
in this table are typical; actual values obtained are dependent
analyzed.
on instrument design and set-up.
4. Summary of Test Method
7. Apparatus
4.1 A unipolar triggered capacitor discharge is produced in
7.1 Specimen Preparation Equipment:
an argon atmosphere between the prepared flat surface of a
7.1.1 Sampling Molds, for magnesium the techniques of
specimen and the tip of a semi-permanent counter electrode.
pouring a sample disk are described in Practice B953. Chill
Theenergyofthedischargeissufficienttoablatematerialfrom
cast samples, poured and cast as described within Practice
the surface of the sample, break the chemical or physical
B953 shall be the recommended form in this test method.
bonds, and cause the resulting atoms or ions to emit radiant
7.1.2 Lathe, capable of machining a smooth, flat surface on
energy.The radiant energies of the selected analytical lines and
thereferencematerialsandsamples.Eitheralloysteel,carbide-
theinternalstandardline(s)areconvertedintoelectricalsignals
tipped, or carbide insert tool bits are recommended. Proper
by either photomultiplier tubes (PMTs) or a suitable solid state
depth of cut and desired surface finish are described in Practice
detector. The detector signals are electrically integrated and
B953.
converted to a digitized value. The signals are ratioed to the
7.1.3 Milling Machine—A milling machine can be used as
proper internal standard signal and converted into concentra-
an alternative to a lathe.
tions by a computer in accordance with Practice E158.
7.1.4 Metallographic Polisher/Grinder—A metallographic
4.2 Three different methods of calibration defined in 3.2.1, polisher/grindermayalsobeusedtopreparethesamplesurface
3.2.2 and 3.2.3, are capable of giving equivalent precision, provided care has been taken in the selection a non-
accuracy and detection limits. contaminating abrasive compound. Metallographic grade wet/
4.2.1 The first method, binary calibration, employs calibra- dry silicon carbide discs of 120 grit or higher will produce a
tion curves that are determined using a large number of goodsamplesurfacewithessentiallynosiliconcarryovertothe
high-puritybinarycalibrants.Thisapproachisusedwhenthere sample. This must be verified by making a comparison
B954 − 07
TABLE 1 Recommended Analytical Lines
Recommended Background Detection
Wavelength in Air Interferences Element,
Element Concentration Equivalent, Limit,
A
(nm) λ(nm)
B C
Range, % % %
Aluminum 396.15 I 0.001 – 0.5 0.008 0.0001* Zr 396.16
Aluminum 256.80 I 1.0 – 12.0 Zn 256.81
Ar 256.81
Aluminum 266.04 I 1.0 – 12.0
Aluminum 394.40 I 0.001 – 0.5 0.002
Aluminum 308.22 I 1.0 – 12.0 0.09 Mn 308.21
Beryllium 313.04 II 0.0001 – 0.01 0.0005 0.0001 Ag 313.00
Ce 313.09
Boron 182.64 I Co 182.60
Mg 182.68
Boron 249.68 I Fe 249.65
Fe 249.70
Al 249.71
Ce 249.75
Cadmium 226.50 II 0.0001 – 0.05 0.002 0.00005 Ce 226.49
Ni 226.45
Fe 226.44
Cadmium 228.80 I 0.00003 – 0.1 Ce 228.78
Ni 228.77
Fe 228.73
Calcium 393.37 II 0.0005 – 0.05 0.0002 0.0002 Fe 393.36
Ce 393.37
Zr 393.41
Cerium 413.77 II 0.01 – 3.0 Zr 413.74
Fe 413.78
Cerium 418.66 II 0.01 – 3.0 Dy 418.68
Chromium 425.44 I 0.0002 – 0.005 Ce 425.34
Cu 425.56
Copper 324.75 I 0.001 – 0.05 0.003 0.0001 Mn 324.75
Mn 324.85
Dysprosium 353.17 II 0.01 – 1.0 Mn 353.19
Mn 353.21
Erbium 400.80 II 0.01 – 1.0 0.08 0.001 Mn 400.80
Sm 400.81
Gadolinium 379.64 0.01 – 3.0 0.1 0.001 Zr 379.65
Iron 259.94 II 0.001 – 0.06 0.023 0.0005 Mn 259.89
Iron 238.20 II Zn 238.22
Ce 238.23
Zr 238.27
Iron 371.99 I 0.001 – 0.06 0.007 Ti 372.04
Lanthanum 433.37 II 0.01 – 1.5 0.1 0.001 Pr 433.39
Sm 433.41
Lead 368.35 I 0.005 – 0.1 Fe 368.31
Mn 368.35
Zn 368.35
Lead 363.96 I 0.05 – 0.5 Zn 363.95
Fe 364.04
Lead 217.00 I 0.005 – 0.1 0.04 Mn 216.98
Ce 216.95
Lithium 670.78 I 0.001 – 0.05
Lithium 610.36 I
Magnesium 291.55 I Internal Standard Mn 291.46
Al 291.57
Magnesium 517.27 I Internal Standard Fe 517.16
Manganese 257.61 II 0.001 – 0.5 Mn 257.57
Fe 257.69
Manganese 259.37 II 0.002 – 0.5 Mg 259.32
Zr 259.37
Fe 259.37
Manganese 293.31 II 0.001 – 2 0.12
Manganese 403.08 I 0.001 – 0.5 0.006 0.0002 Zr 403.07
Fe 403.05
Manganese 403.45 I 0.01 – 0.5
Neodymium 406.11 II 0.01 – 3.0 Mn 406.17
Nickel 231.60 II 0.001 – 0.05
Nickel 351.51 I 0.001 – 0.05 Zn 351.51
Nickel 341.48 I 0.0005 – 0.05 0.015 0.0003 Zr 341.47
Phosphorous 178.28 I 0.0002 – 0.01 0.009 0.0001 Zr 178.33
Praseodymium 422.30 0.01 – 0.5 0.1 0.001
Samarium 356.83 II 0.01 – 1.0 0.1 0.001 Fe 356.84
Silicon 251.61 I 0.002 – 1.5 0.013 Zn 251.58
V 251.61
Al 251.59
B954 − 07
TABLE 1 Continued
Recommended Background Detection
Wavelength in Air Interferences Element,
Element Concentration Equivalent, Limit,
A
(nm) λ(nm)
B C
Range, % % %
Silicon 288.16 I 0.002 – 1.5 0.088 0.0006 Al 288.15
Silicon 390.55 I 0.5 – 5 1.0? Mn 390.50
Silver 338.29 I 0.001 – 0.2 Fe 338.24
Silver 235.79 II
Sodium 588.99 I 0.0005 – 0.01 0.0002 0.0002
Sodium 589.59 I 0.0005 – 0.01 0.0002 0.0002
Strontium 460.73 I 0.01 – 4.0 Mn 460.76
Tin 284.00 I 0.002 – 0.05 Mn 284.00
Fe 284.04
Tin 317.50 I 0.002 – 0.5 0.062 0.0004 Mn 317.47
Fe 317.54
Titanium 337.28 II 0.001 – 0.02 0.005 Zr 337.34
Ce 337.37
Yttrium 417.76 II 0.02 – 7.0 0.06 0.0005 Fe 417.76
Nd 417.73
Ytterbium 328.94 0.01 – 1.0 0.0002 0.0001 Y 328.99
Zinc 213.86 I 0.001 – 0.1 0.001 Low line Zr 213.85
Zr 213.99
Zinc 334.50 I 0.01 – 3.0 High line Al 334.45
Ce 334.48
Zr 334.48
Mn 334.54
Zinc 481.05 I 0.05 – 10.0 0.09 0.001 Nd 481.13
Zirconium 339.20 II 0.001 – 1.0 0.027 0.0002 Fe 339.20
Fe 339.23
Zirconium 343.82 II 0.001 – 1.0 Ni 343.73
Fe 343.83
Zirconium 349.62 II 0.001 – 1.0 0.005 Mn 349.58
Y 349.61
A
I = atom line, II = ion line.
B
Background Equivalent—The concentration at which the signal due to the element is equal to the signal due to the background.
C
Inthistestmethod,thedetectionlimitwasmeasuredbycalculatingthestandarddeviationoftenconsecutiveburnsonaspecimenwithelementconcentration(s)atlevels
belowtentimestheexpecteddetectionlimit.Forthevaluesmarkedwithanasterisk(*)theavailabledatawasforaconcentrationgreaterthanten(10)timesbutlessthan
a hundred (100) times the expected detection limit.
between freshly prepared surfaces on a polisher/grinder to that 7.3 Excitation Chamber shall be designed with an upper
of a lathe or milling machine. Reference Guide E1257 for a plate that is smooth and flat so that it will mate (seal) perfectly
description of contamination issues with various abrasive withthepreparedsurfaceofthesamplespecimen.Thesealthat
compounds. is formed between the two will exclude atmospheric oxygen
from entering the discharge chamber. The excitation chamber
7.2 Excitation Source, capable of producing a unipolar
will contain a mounting clamp to hold the counter electrode.
triggered capacitor discharge. In today’s i
...
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