ASTM D7639-10
(Test Method)Standard Test Method for Determination of Zirconium Treatment Weight or Thickness on Metal Substrates by X-Ray Fluorescence
Standard Test Method for Determination of Zirconium Treatment Weight or Thickness on Metal Substrates by X-Ray Fluorescence
SIGNIFICANCE AND USE
The procedure described in this test method is designed to provide a method by which the coating weight of zirconium treatments on metal substrates may be determined.
This test method is applicable for determination of the total coating weight and the zirconium coating weight of a zirconium-containing treatment.
SCOPE
1.1 This test method covers the use of X-ray fluorescence (XRF) spectrometry for the determination of the mass of zirconium (Zr) coating weight per unit area of metal substrates.
1.2 Coating treatments can also be expressed in units of linear thickness provided that the density of the coating is known, or provided that a calibration curve has been established for thickness determination using standards with treatment matching this of test specimens to be analyzed. For simplicity, the method will subsequently refer to the determination expressed as coating weight.
1.3 XRF is applicable for the determination of the coating weight as zirconium or total coating weight of a zirconium containing treatment, or both, on a variety of metal substrates.
1.4 The maximum measurable coating weight for a given coating is that weight beyond which the intensity of the characteristic X-ray radiation from the coating or the substrate is no longer sensitive to small changes in weight.
1.5 The values stated in SI units are regarded as the standard.
1.6 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.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D7639 − 10
StandardTest Method for
Determination of Zirconium Treatment Weight or Thickness
on Metal Substrates by X-Ray Fluorescence
This standard is issued under the fixed designation D7639; 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.
1. Scope 3. Summary of Test Method
1.1 This test method covers the use of X-ray fluorescence
3.1 The test specimen is placed in the X-ray beam, and the
(XRF) spectrometry for the determination of the mass of resultant peak intensity of the zirconium Ka line (at 0.0786 nm
zirconium(Zr)coatingweightperunitareaofmetalsubstrates.
or 15.747 keV) or the zirconium La line (at 0.606 nm or 2.042
keV) is measured. The intensity (in counts or counts per
1.2 Coating treatments can also be expressed in units of
second) is then compared to a previously prepared calibration
linear thickness provided that the density of the coating is
curve or equation to obtain the coating weight of zirconium
known, or provided that a calibration curve has been estab-
2 2
treatment in mg/m or mg/ft (or µm or nm).
lished for thickness determination using standards with treat-
ment matching this of test specimens to be analyzed. For 3.2 The exact relationship between the measured number of
simplicity, the method will subsequently refer to the determi- counts and the corresponding coating weight (or coating
nation expressed as coating weight. thickness) must be established for each individual combination
of substrate and zirconium-containing treatment. Usually de-
1.3 XRF is applicable for the determination of the coating
termined by the treatment supplier, this relationship is estab-
weight as zirconium or total coating weight of a zirconium
lished by using primary standards having known amounts of
containing treatment, or both, on a variety of metal substrates.
the same treatment applied to the same substrate composition
1.4 The maximum measurable coating weight for a given
as the test specimens to be measured.
coating is that weight beyond which the intensity of the
characteristic X-ray radiation from the coating or the substrate
4. Significance and Use
is no longer sensitive to small changes in weight.
4.1 The procedure described in this test method is designed
1.5 The values stated in SI units are regarded as the
to provide a method by which the coating weight of zirconium
standard.
treatments on metal substrates may be determined.
1.6 This standard does not purport to address all of the
4.2 This test method is applicable for determination of the
safety concerns, if any, associated with its use. It is the
total coating weight and the zirconium coating weight of a
responsibility of the user of this standard to establish appro-
zirconium-containing treatment.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Apparatus
2. Referenced Documents
5.1 X-RayFluorescenceSpectrometer,capableofmeasuring
the intensity of zirconium Ka or La line, and establish the
2.1 ASTM Standards:
relationship between peak intensity and coating weight. The
E177 Practice for Use of the Terms Precision and Bias in
spectrometer’s design must include, as a minimum, the follow-
ASTM Test Methods
ing features:
E691 Practice for Conducting an Interlaboratory Study to
5.1.1 SourceofX-RayExcitation,X-raytubewithexcitation
Determine the Precision of a Test Method
above 2.55 keV if measuring the zirconium La line, or above
18 keV if measuring the zirconium Ka line.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
5.1.2 X-Ray Detector, with high sensitivity and capable of
and Related Coatings, Materials, andApplications and is the direct responsibility of
discriminating between zirconium La or Ka radiation and other
Subcommittee D01.53 on Coil Coated Metal.
X-rays of higher or lower energies.
Current edition approved June 1, 2010. Published June 2010. DOI:10.1520/
D7639–10.
5.1.2.1 In the case of wavelength dispersive X-ray fluores-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cence(WDXRF),thiscanbeananalyzingcrystal(forexample,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
fixed channel, goniometer) setup to detect the zirconium
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. X-rays (La or Ka line). Germanium 111 has been found to be
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7639 − 10
acceptable for the Zirconium La line and LiF220 or LiF200 for 6.8 The calibration standards and test specimens should be
the zirconium Ka line. measured over the X-ray port using the same rolling direction
of the metal. This is not necessary for instruments operating
5.1.2.2 In the case of energy dispersive X-ray fluorescence
with a sample spinner.
(EDXRF), it can be a proportional counter, or a semiconductor
such as a PIN diode or a silicon-drift detector.
7. Calibration Procedure
5.1.3 Pulse-Height Analyzer, or other means of energy
7.1 Set up the instrument calibration and operating param-
discrimination.
eters according to the chemical supplier and instrument manu-
5.1.4 Optical Path, specified by manufacturer. A helium or
facturer’s recommendations.
vacuum path is recommended when measuring the zirconium
La line in order to minimize the attenuation of the X-rays by
7.2 Establish calibration curve by carefully determining the
the air in the optical path. The zirconium Ka line has a higher intensity of the emitted zirconium radiation from each of the
energy and its intensity will not be affected by air.
calibration standards (a minimum of five standards is recom-
mended). Obtain three readings for each standard (measured
5.1.5 Signal Conditioning and Data Handling System,
whereby a coating weight versus X-ray counts curve may be across the standard’s surface if it is suspected that the zirco-
nium coating weight might be varying).
established within the system for the direct readout of coating
weight.
7.3 Construct a calibration by using the software and
5.1.6 Sample Spinner (optional), to reduce the effects of
algorithms supplied by the equipment manufacturer, establish-
coating weight variation across the test specimen.
ingtherelationshipbetweenzirconiumintensityandzirconium
treatment coating weight.
6. Calibration Standards and Test Specimens
7.4 When using drift correction monitors, determine the
6.1 Calibration Standards should be specimens for which
intensity of the drift correction monitor sample(s).
the coating weight has been well characterized by other
7.5 Immediately after completing the calibration, determine
analytical procedures such as x-ray photoelectron spectros-
the zirconium coating weight of one or more calibration check
copy, Auger emission spectroscopy, glow discharge optical
sample. Check samples can be stable, well-characterized ma-
emission spectrometry, weigh-strip-weigh method, or other
terials. The differences between two measured values shall be
depth-profiling analytical technique.
withintherepeatabilityofthistestmethod.Whenthisisnotthe
case, the stability of the instrument and the repeatability of the
6.2 Blank (bare and untreated) Specimen (optional), should
be of the same metal substrate on which the treatment coating sample preparation should be investigated and corrective
measures taken. Calibration check samples should have the
weight is to be determined. It may be necessary to prepare a
same substrate and same treatment as calibration standards and
blank specimen from
...
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