ASTM E716-16(2021)e1

Standard Practices for Sampling and Sample Preparation of Aluminum and Aluminum Alloys for Determination of Chemical Composition by Spark Atomic Emission Spectrometry

SIGNIFICANCE AND USE
5.1 The practice for taking a sample of molten metal during production and producing a chill cast disk, used in conjunction with the following appropriate quantitative spark atomic emission spectrochemical methods, Test Methods E607 and E1251, is suitable for use in manufacturing control or certifying, or both, that the entire lot of alloy sampled meets established composition limits.  
5.2 The practice for melting a piece of a product to produce a chill cast disk analyzed in conjunction with the following appropriate quantitative spark atomic emission spectrochemical methods, Test Methods E607 and E1251, is suitable, if a representative sample is taken, for determining if the piece sampled meets Aluminum Association composition limits.  
5.3 The practice for direct analysis of product is suitable for determining an approximate composition of the piece analyzed.
SCOPE
1.1 These practices describe procedures for producing a chill cast disk sample from molten aluminum during the production process, and from molten metal produced by melting pieces cut from products.  
1.2 These practices describe a procedure for obtaining qualitative results by direct analysis of product using spark atomic emission spectrometry.  
1.3 These practices describe procedures for preparation of samples and products prior to analysis.  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in 6.1 and 7.2.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 14-Nov-2021
• ICS: 77.040.30 - Chemical analysis of metals
• Technical Committee: E01 - Analytical Chemistry for Metals, Ores, and Related Materials
• Drafting Committee: E01.04 - Aluminum and Magnesium

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: E716 − 16 (Reapproved 2021)
Standard Practices for
Sampling and Sample Preparation of Aluminum and
Aluminum Alloys for Determination of Chemical
Composition by Spark Atomic Emission Spectrometry
This standard is issued under the fixed designation E716; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—An editorial change was made to 8.3 in January 2022.
1. Scope* 2. Referenced Documents
1.1 These practices describe procedures for producing a 2.1 ASTM Standards:
chill cast disk sample from molten aluminum during the B985Practice for SamplingAluminum Ingots, Billets, Cast-
production process, and from molten metal produced by ings and Finished or Semi-Finished Wrought Aluminum
melting pieces cut from products. Products for Compositional Analysis
E135Terminology Relating to Analytical Chemistry for
1.2 These practices describe a procedure for obtaining
Metals, Ores, and Related Materials
qualitative results by direct analysis of product using spark
E401Practice for Bonding Thin Spectrochemical Samples
atomic emission spectrometry.
and Standards to a Greater Mass of Material (Withdrawn
1.3 These practices describe procedures for preparation of
1995)
samples and products prior to analysis.
E607 Test Method for Atomic Emission Spectrometric
Analysis Aluminum Alloys by the Point to Plane Tech-
1.4 The values stated in SI units are to be regarded as
standard. The values given in parentheses are mathematical nique Nitrogen Atmosphere (Withdrawn 2011)
E1251Test Method for Analysis of Aluminum and Alumi-
conversions to inch-pound units that are provided for informa-
tion only and are not considered standard. num Alloys by Spark Atomic Emission Spectrometry
1.5 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 3.1 For definitions of terms used in this practice, refer to
priate safety, health, and environmental practices and deter- Terminology E135.
mine the applicability of regulatory limitations prior to use.
4. Summary of Practices
Specific precautionary statements are given in 6.1 and 7.2.
1.6 This international standard was developed in accor-
4.1 Molten metal representative of the furnace melt is
dance with internationally recognized principles on standard-
poured or drawn by vacuum into a specified mold to produce
ization established in the Decision on Principles for the
a chill-cast disk.The disk is machined to a specified depth that
Development of International Standards, Guides and Recom-
representstheaveragecompositionandproducesanacceptable
mendations issued by the World Trade Organization Technical
surface for analysis by spark atomic emission spectrometry.
Barriers to Trade (TBT) Committee.
1 2
These practices are under the jurisdiction of ASTM Committee E01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Analytical Chemistry for Metals, Ores, and Related Materials and are the direct contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
responsibility of Subcommittee E01.04 on Aluminum and Magnesium. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 15, 2021. Published November 2021. Originally the ASTM website.
approved in 1980. Last previous edition approved in 2016 as E716–16. DOI: The last approved version of this historical standard is referenced on
10.1520/E0716-16R21E01. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E716 − 16 (2021)
NOTE 2—Molten aluminum in contact with rust may initiate a thermite
4.2 Pieces of solid aluminum fabricated, cast, or wrought
reaction.
products are remelted and cast into molds or briquetted then
remelted and cast into molds. 6.2 Sample Molds shall be capable of producing homog-
enous chill-cast disks having smooth surfaces, free of surface
4.3 Product can be qualitatively analyzed directly without
pockets and porosity. These chill cast disks should have a
remelting after suitable surface preparation. Product with
spectrochemical response similar to the reference materials
insufficient mass for direct analysis may be bonded to more
usedinpreparingtheanalyticalcurvesandshouldatleasthave
massive material prior to analysis.
a spark to spark repeatability of no more than 2% relative on
4.4 Special practices are included for the sampling and
major elements.They must be representative of the melt in the
analysis of aluminum-silicon alloys, containing greater than
region excited. Several types of molds have been found
14% silicon.
acceptable:
6.2.1 TypeB Mold center-pour mold, is shown in Fig. 1.
5. Significance and Use
Thismoldproducesahorizontallycastdiskwiththesprueover
5.1 The practice for taking a sample of molten metal during
the center of one side. The mold dimensions are such as to
production and producing a chill cast disk, used in conjunction
produce a disk approximately 50mm to 64mm (1.97in. to
with the following appropriate quantitative spark atomic emis- 2.5in.) in diameter by 6mm to 13mm (0.24in. to 0.50in.) in
sion spectrochemical methods,Test Methods E607 and E1251,
thickness.Acircular central recess 10mm to 20mm (0.4in. to
is suitable for use in manufacturing control or certifying, or
0.8in.) in diameter on one side of the disk facilitates machin-
both, that the entire lot of alloy sampled meets established
ing of that side in preparation for excitation. It also promotes
composition limits.
more uniform freezing of the raised peripheral area, but the
corresponding raised portion of the mold must not be so large
5.2 The practice for melting a piece of a product to produce
astorestrictthethroatforthesprue.Aslighttaper,1°to2°,on
a chill cast disk analyzed in conjunction with the following
the hinged portion of the mold facilitates opening when a disk
appropriate quantitative spark atomic emission spectrochemi-
has been cast. The mold material should be steel or cast iron
cal methods, Test Methods E607 and E1251, is suitable, if a
and should weigh approximately 3.5kg to 4.5kg (8lb to
representative sample is taken, for determining if the piece
10lb).AspecialTypeBmoldisrecommendedforhypereutetic
sampled meets Aluminum Association composition limits.
aluminum-silicon alloys. It produces the thinner samples
5.3 Thepracticefordirectanalysisofproductissuitablefor
13mm (0.24 in.) thick.
determining an approximate composition of the piece ana-
NOTE 3—About sample molds: Previously two relatively simple types
lyzed.
of massive iron or steel sample molds were considered suitable, Type A
and Type B. Type A molds produced vertical chill cast samples with the
6. Apparatus
sprueandriserontheedgeofthesample,asopposedtotheTypeBwhich
producesahorizontalchillcastsamplewiththesprueandriserontheback
6.1 Ladle, capable of holding a minimum of 250g (8.8oz)
of the sample. The Type A sampler was later found to not produce a
ofmoltenmetal,withahandleofsufficientlengthtoreachinto
repeatable sparking surface, even in the restricted sparking areas. The
a furnace, trough, or crucible. The ladle should be lightly
Type A mold was removed from the list of recommended conventional
coatedwithatightlyadheringladlewashthatwillserveinpart
molds. Because many people are familiar with the terms “Type A” and
to prevent contamination of the sample and also prevent “Type B” molds, reference to “Type B” mold remains in the text of this
standard even though reference to the “Type A” no longer appears.
contact of molten aluminum with metal oxides, that is, rust.
(Warning—Traces of moisture in the coating may cause
dangerous spattering.)
NOTE 1—Asuitable ladle wash may be prepared as follows: Mix 255g
(9oz) of fine whiting (CaCO ) with 3.8L (1gal) of water and boil for
TypeB molds, available from Danton Machine and Welding Incorporated, 713
20min.Add 127g (4.5oz) of sodium silicate solution (40°Bé to 42°Bé)
FortuneCrescent,Kingston,ONCanadaK7P2T4,havebeenfoundsuitableforthis
and boil for 30min. Stir well before using. purpose.
FIG. 1 Type B Mold
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E716 − 16 (2021)
6.2.2 Scissor Mold is shown in Fig. 2. This mold produces
disks that are 60 mm (2.4 in.) in diameter and 13 mm (0.5 in.)
thick and weigh approximately 100 g (3.5 oz). The mold
consists of two halves weighing about 3 kg (6.6 lbs). The
halvesareconnectedbyapivotboltwhichallowsthehalvesto
functionasscissors.Whentheupperhalfwiththesprueholeis
moved to cover the sample cavity in the lower half, molten
metal is poured into the riser cup, through the sprue hole into
thesamplecavity.Afterthemetalhasfrozen,theuserholdsthe
steel spring heat dissipater surrounding one handle and strikes
the other handle on the ground causing the upper half to pivot
away and shear off the riser at the sprue. The sample and the
sprue can then be easily removed.
6.2.3 Vacuum Mold is shown in Fig. 3. This mold produces
disks that are 38mm (1.5in.) in diameter and 13mm (0.5in.)
thick and weigh approximately 40g (1.4oz). The mold con-
sists of a solid copper base and a porous bronze wall in the
form of a composite mold insert which is located in a steel
mold body. A graphite coated cast iron tip is attached to the
mold body by a spring clamp assembly. The vacuum source is
typically a rubber syringe bulb connected to the mold body.
FIG. 3 Mold for Vacuum Cast Samples
NOTE 4—This sampler is made by Alcoa and is recommended in
previous issues of this standard. This device is no longer commercially
available fromAlcoa, but the description remains in this standard because
it is still used within the aluminum industry.
6.2.4 OtherTypesofMolds—Othermoldsofdifferenttypes,
materials,anddimensionsmaybesubstitutedprovidedthatthe
uniformity of the samples so obtained is sufficient for the
intended use of the results. Furthermore such samples should
have a spectrochemical response similar to the reference
materials used for preparing the analytical curve.
6.3 Lathe or Milling Machine, capable of machining a
smooth flat surface and capable of repeating the selected depth
of cut to within 60.013mm (60.005 in.).
6.4 Tool Bits—Diamond tipped, or alloy steel, or cemented
carbide bits are recommended.The best shape of the lathe tool
varies with the type and speed of the lathe. A tool bit design
that has been found satisfactory for most aluminum alloys is
shown in Fig. 4.
FIG. 4 Tool Bit
6.5 An Electric Melting Furnace, using a clay or graphite
A scissor mold available from Herschal Products, 3778 Timberlake Dr., crucible with a minimum capacity of 100 g (3.5 oz) of molten
Richfield, OH 44286 has been found suitable for this purpose.
aluminumandcapableofmaintainingtemperaturesformelting
aluminum alloys.
7. Materials
7.1 Graphite Rods, for stirring the molten aluminum.
7.2 Asourceofphosphorus,forgrainrefiningofhighsilicon
alloys before spectrometric analysis. Grain refining of the
primary silicon is important for an accurate analysis of silicon.
NOTE 5—Previous versions of these standard practices specified the
addition of red phosphorus to the sample ladle of molten hypereutectic
Al-Si aluminum alloy. The requirement of the addition of red phosphorus
Graphite stirring rods are available from Budget Casting Supply LLC, 20811
FIG. 2 Scissor Mold Upper Hillview Dr., Sonora, CA 95370
´1
E716 − 16 (2021)
was based on the assumption that the larger quantity of molten aluminum grinding. Sanding or grinding tends to smear the relatively soft aluminum
alloy (which was sampled by the ladle) had not previously been grain phase over the harder constituent phases or cause hard grains to be torn
refined with phosphorus. Red phosphorus is no longer available without a from the sample and may cause biased results for spark atomic emission
speciallicense.Therecommendedreplacementgrainrefiningadditiveisa spectrometry.
copper-8 % phosphorus alloy. The entire molten bath should be refined
8.1.4.1 The machined surface must be smooth and free of
before the sample ladle removes the smaller amount of molten metal for
scuffs, pits, or inclusions. The ideal surface is neither polished
the sample. If the sample must be taken prior to grain refinement of the
main bath, either a small amount of copper-8 % phosphorus alloy should nor visibly grooved but should be a surface showing very fine
be added to the ladle, with the expectation that the copper concentration
tool marks. More specifically, the ideal surface may be defined
of the spectrometric analysis will be wrong, or a phosphorus chemical
as approximately a 1.6×10−3-mm (63-µin.) standard machine
compound without an interfering element should be added. This other
finish. A surface much finer or much coarser may result in an
compound will be hazardous and must be handled carefully by an
apparentanalyticaldifference.Furthermore,itisimportantthat
experienced chemist. A suitable compound is phosphorus penta-chloride
(PCl ). In either case, the phosphorus recovery after the alloying addition
both sample and reference material have the same machine
will be low, in a range of 15% to 40%.
finish. Analysis can be made 360° around the disk in the
annular area adjacent to the edge, avoiding the center area.
8. Preparation of Samples
8.1.5 Other Accepted Molds—If molds other than TypeB,
8.1 Molten Metal:
the scissor mold, or the vacuum mold are used, the same
8.1.1 When molten metal is to be sampled, the temperature
instructionsgivenin8.1wouldapply.Inaddition,sinceamold
mustbewellabovethepointatwhichanysolidphasecouldbe
of different dimensions may result in a different freezing
present. Using the ladle or a separate skimming tool, coated
pattern, each new type of mold must be evaluated in order to
withadry,tightlyadheringmoldwash(Note1)andfreeofany
ascertain the proper depth of machining to represent the true
remaining previous metal, push as much dross as possible
composition of the melt.
awayfromthesamplingarea.Next,diptheladlesidewaysinto
8.2 Remelting and Casting a Sample from Fabricated and
the clear area well below the surface and stir momentarily.
Cast Products:
Then turn the ladle upright, and quickly withdraw. Two things
are thus accomplished, namely, heating the ladle prevents 8.2.1 Chill-Cast Disk by TypeB Mold, the Scissor Mold, or
the Vacuum Mold—When the metal to be analyz
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: E716 − 16 (Reapproved 2021) E716 − 16 (Reapproved 2021)
Standard Practices for
Sampling and Sample Preparation of Aluminum and
Aluminum Alloys for Determination of Chemical
Composition by Spark Atomic Emission Spectrometry
This standard is issued under the fixed designation E716; 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.
ε NOTE—An editorial change was made to 8.3 in January 2022.
1. Scope*
1.1 These practices describe procedures for producing a chill cast disk sample from molten aluminum during the production
process, and from molten metal produced by melting pieces cut from products.
1.2 These practices describe a procedure for obtaining qualitative results by direct analysis of product using spark atomic emission
spectrometry.
1.3 These practices describe procedures for preparation of samples and products prior to analysis.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to
inch-pound units that are provided for information only and are not considered standard.
1.5 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. Specific precautionary statements are given in 6.1 and 7.2.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
B985 Practice for Sampling Aluminum Ingots, Billets, Castings and Finished or Semi-Finished Wrought Aluminum Products for
Compositional Analysis
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
E401 Practice for Bonding Thin Spectrochemical Samples and Standards to a Greater Mass of Material (Withdrawn 1995)
These practices are under the jurisdiction of ASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and are the direct responsibility
of Subcommittee E01.04 on Aluminum and Magnesium.
Current edition approved Nov. 15, 2021. Published November 2021. Originally approved in 1980. Last previous edition approved in 2016 as E716 – 16. DOI:
10.1520/E0716-16R21.10.1520/E0716-16R21E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
E716 − 16 (2021)
E607 Test Method for Atomic Emission Spectrometric Analysis Aluminum Alloys by the Point to Plane Technique Nitrogen
Atmosphere (Withdrawn 2011)
E1251 Test Method for Analysis of Aluminum and Aluminum Alloys by Spark Atomic Emission Spectrometry
3. Terminology
3.1 For definitions of terms used in this practice, refer to Terminology E135.
4. Summary of Practices
4.1 Molten metal representative of the furnace melt is poured or drawn by vacuum into a specified mold to produce a chill-cast
disk. The disk is machined to a specified depth that represents the average composition and produces an acceptable surface for
analysis by spark atomic emission spectrometry.
4.2 Pieces of solid aluminum fabricated, cast, or wrought products are remelted and cast into molds or briquetted then remelted
and cast into molds.
4.3 Product can be qualitatively analyzed directly without remelting after suitable surface preparation. Product with insufficient
mass for direct analysis may be bonded to more massive material prior to analysis.
4.4 Special practices are included for the sampling and analysis of aluminum-silicon alloys, containing greater than 14 % silicon.
5. Significance and Use
5.1 The practice for taking a sample of molten metal during production and producing a chill cast disk, used in conjunction with
the following appropriate quantitative spark atomic emission spectrochemical methods, Test Methods E607 and E1251, is suitable
for use in manufacturing control or certifying, or both, that the entire lot of alloy sampled meets established composition limits.
5.2 The practice for melting a piece of a product to produce a chill cast disk analyzed in conjunction with the following appropriate
quantitative spark atomic emission spectrochemical methods, Test Methods E607 and E1251, is suitable, if a representative sample
is taken, for determining if the piece sampled meets Aluminum Association composition limits.
5.3 The practice for direct analysis of product is suitable for determining an approximate composition of the piece analyzed.
6. Apparatus
6.1 Ladle, capable of holding a minimum of 250 g (8.8 oz) of molten metal, with a handle of sufficient length to reach into a
furnace, trough, or crucible. The ladle should be lightly coated with a tightly adhering ladle wash that will serve in part to prevent
contamination of the sample and also prevent contact of molten aluminum with metal oxides, that is, rust. (Warning—Traces of
moisture in the coating may cause dangerous spattering.)
NOTE 1—A suitable ladle wash may be prepared as follows: Mix 255 g (9 oz) of fine whiting (CaCO ) with 3.8 L (1 gal) of water and boil for 20 min.
Add 127 g (4.5 oz) of sodium silicate solution (40 °Bé to 42 °Bé) and boil for 30 min. Stir well before using.
NOTE 2—Molten aluminum in contact with rust may initiate a thermite reaction.
6.2 Sample Molds shall be capable of producing homogenous chill-cast disks having smooth surfaces, free of surface pockets and
porosity. These chill cast disks should have a spectrochemical response similar to the reference materials used in preparing the
analytical curves and should at least have a spark to spark repeatability of no more than 2 % relative on major elements. They must
be representative of the melt in the region excited. Several types of molds have been found acceptable:
6.2.1 Type B Mold center-pour mold, is shown in Fig. 1. This mold produces a horizontally cast disk with the sprue over the center
of one side. The mold dimensions are such as to produce a disk approximately 50 mm to 64 mm (1.97 in. to 2.5 in.) in diameter
Type B molds, available from Danton Machine and Welding Incorporated, 713 Fortune Crescent, Kingston, ON Canada K7P 2T4, have been found suitable for this
purpose.
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E716 − 16 (2021)
FIG. 1 Type B Mold
by 6 mm to 13 mm (0.24 in. to 0.50 in.) in thickness. A circular central recess 10 mm to 20 mm (0.4 in. to 0.8 in.) in diameter on
one side of the disk facilitates machining of that side in preparation for excitation. It also promotes more uniform freezing of the
raised peripheral area, but the corresponding raised portion of the mold must not be so large as to restrict the throat for the sprue.
A slight taper, 1° to 2°, on the hinged portion of the mold facilitates opening when a disk has been cast. The mold material should
be steel or cast iron and should weigh approximately 3.5 kg to 4.5 kg (8 lb to 10 lb). A special Type B mold is recommended for
hypereutetic aluminum-silicon alloys. It produces the thinner samples 13 mm (0.24 in.) thick.
NOTE 3—About sample molds: Previously two relatively simple types of massive iron or steel sample molds were considered suitable, Type A and Type
B. Type A molds produced vertical chill cast samples with the sprue and riser on the edge of the sample, as opposed to the Type B which produces a
horizontal chill cast sample with the sprue and riser on the back of the sample. The Type A sampler was later found to not produce a repeatable sparking
surface, even in the restricted sparking areas. The Type A mold was removed from the list of recommended conventional molds. Because many people
are familiar with the terms “Type A” and “Type B” molds, reference to “Type B” mold remains in the text of this standard even though reference to the
“Type A” no longer appears.
6.2.2 Scissor Mold is shown in Fig. 2. This mold produces disks that are 60 mm (2.4 in.) in diameter and 13 mm (0.5 in.) thick
and weigh approximately 100 g (3.5 oz). The mold consists of two halves weighing about 3 kg (6.6 lbs). The halves are connected
by a pivot bolt which allows the halves to function as scissors. When the upper half with the sprue hole is moved to cover the
sample cavity in the lower half, molten metal is poured into the riser cup, through the sprue hole into the sample cavity. After the
metal has frozen, the user holds the steel spring heat dissipater surrounding one handle and strikes the other handle on the ground
causing the upper half to pivot away and shear off the riser at the sprue. The sample and the sprue can then be easily removed.
6.2.3 Vacuum Mold is shown in Fig. 3. This mold produces disks that are 38 mm (1.5 in.) in diameter and 13 mm (0.5 in.) thick
and weigh approximately 40 g (1.4 oz). The mold consists of a solid copper base and a porous bronze wall in the form of a
composite mold insert which is located in a steel mold body. A graphite coated cast iron tip is attached to the mold body by a spring
clamp assembly. The vacuum source is typically a rubber syringe bulb connected to the mold body.
NOTE 4—This sampler is made by Alcoa and is recommended in previous issues of this standard. This device is no longer commercially available from
Alcoa, but the description remains in this standard because it is still used within the aluminum industry.
FIG. 2 Scissor Mold
A scissor mold available from Herschal Products, 3778 Timberlake Dr., Richfield, OH 44286 has been found suitable for this purpose.
´1
E716 − 16 (2021)
FIG. 3 Mold for Vacuum Cast Samples
6.2.4 Other Types of Molds—Other molds of different types, materials, and dimensions may be substituted provided that the
uniformity of the samples so obtained is sufficient for the intended use of the results. Furthermore such samples should have a
spectrochemical response similar to the reference materials used for preparing the analytical curve.
6.3 Lathe or Milling Machine, capable of machining a smooth flat surface and capable of repeating the selected depth of cut to
within 60.013 mm (60.005 in.).
6.4 Tool Bits—Diamond tipped, or alloy steel, or cemented carbide bits are recommended. The best shape of the lathe tool varies
with the type and speed of the lathe. A tool bit design that has been found satisfactory for most aluminum alloys is shown in Fig.
4.
6.5 An Electric Melting Furnace, using a clay or graphite crucible with a minimum capacity of 100 g (3.5 oz) of molten aluminum
and capable of maintaining temperatures for melting aluminum alloys.
FIG. 4 Tool Bit
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E716 − 16 (2021)
7. Materials
7.1 Graphite Rods, for stirring the molten aluminum.
7.2 A source of phosphorus, for grain refining of high silicon alloys before spectrometric analysis. Grain refining of the primary
silicon is important for an accurate analysis of silicon.
NOTE 5—Previous versions of these standard practices specified the addition of red phosphorus to the sample ladle of molten hypereutectic Al-Si
aluminum alloy. The requirement of the addition of red phosphorus was based on the assumption that the larger quantity of molten aluminum alloy (which
was sampled by the ladle) had not previously been grain refined with phosphorus. Red phosphorus is no longer available without a special license. The
recommended replacement grain refining additive is a copper-8 % phosphorus alloy. The entire molten bath should be refined before the sample ladle
removes the smaller amount of molten metal for the sample. If the sample must be taken prior to grain refinement of the main bath, either a small amount
of copper-8 % phosphorus alloy should be added to the ladle, with the expectation that the copper concentration of the spectrometric analysis will be
wrong, or a phosphorus chemical compound without an interfering element should be added. This other compound will be hazardous and must be handled
carefully by an experienced chemist. A suitable compound is phosphorus penta-chloride (PCl ). In either case, the phosphorus recovery after the alloying
addition will be low, in a range of 15 % to 40 %.
8. Preparation of Samples
8.1 Molten Metal:
8.1.1 When molten metal is to be sampled, the temperature must be well above the point at which any solid phase could be present.
Using the ladle or a separate skimming tool, coated with a dry, tightly adhering mold wash (Note 1) and free of any remaining
previous metal, push as much dross as possible away from the sampling area. Next, dip the ladle sideways into the clear area well
below the surface and stir momentarily. Then turn the ladle upright, and quickly withdraw. Two things are thus accomplished,
namely, heating the ladle prevents metal freezing on the wall and obtaining metal well beneath the surface minimizes the danger
of inclusion of small particles of oxide.
8.1.2 Unless the mold is already hot, cast a preliminary disk into the clean mold in order to preheat it and discard this disk. Remove
excess metal from the ladle, dip into the molten metal as before, and fill the mold with an even rate of pour which allows the escape
of air from the mold. Do not dump the metal into the mold. Avoid overfilling the sprue, otherwise the mold may be difficult to
open. Allow the metal to freeze quietly without jarring. The surface of the disk must be free of any shrinkage, inclusions, cracks,
or roughness.
8.1.3 Chill Cast Disk Using Vacuum Mold—Skim the dross from the molten metal as in 8.1.1, using a skimming tool. Attach the
cast iron mold tip to
...