ASTM C372-94(2020)

Standard Test Method for Linear Thermal Expansion of Porcelain Enamel and Glaze Frits and Fired Ceramic Whiteware Products by Dilatometer Method

SIGNIFICANCE AND USE
4.1 Measurement of thermal expansion is useful for predicting stress within joined materials or single materials under conditions of changing or nonuniform temperature. It can also serve as an indicator of phase composition or changes in structure.
SCOPE
1.1 This test method covers the determination of the linear thermal expansion of premelted frit (porcelain enamel and glaze) and ceramic whiteware products by the thermal dilatometer method. This test method is applicable to apparatus meeting the reproducibility and accuracy requirements of this test method, which are to produce percent linear expansion accuracy of ±3 % or better and coefficient of linear expansion accuracy of ±5 % or better.  
1.2 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.  
1.3 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: Published
• Publication Date: 31-Oct-2020
• ICS: 25.220.50 - Enamels
• Technical Committee: C21 - Ceramic Whitewares and Related Products
• Drafting Committee: C21.03 - Methods for Whitewares and Environmental Concerns

Standards Content (Sample)

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.
Designation: C372 − 94 (Reapproved 2020)
Standard Test Method for
Linear Thermal Expansion of Porcelain Enamel and Glaze
Frits and Fired Ceramic Whiteware Products by Dilatometer
1
Method
This standard is issued under the fixed designation C372; 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.
1. Scope 3. Terminology
1.1 This test method covers the determination of the linear 3.1 Definitions:
thermal expansion of premelted frit (porcelain enamel and 3.1.1 mean coeffıcient of linear thermal expansion—from
glaze)andceramicwhitewareproductsbythethermaldilatom- temperature T to temperature T (T < T ):
1 2 1 2
eter method. This test method is applicable to apparatus
0.01 P
α, mm/mm·°C orin./in.·°C 5
meeting the reproducibility and accuracy requirements of this
T 2 T
2 1
test method, which are to produce percent linear expansion
where:
accuracy of 63% or better and coefficient of linear expansion
accuracy of 65% or better. α = mean coefficient of linear thermal expansion from
temperature T to T , and
1 2
1.2 This standard does not purport to address all of the
P = percent linear thermal expansion as defined in 3.1.2.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 3.1.2 percent linear thermal expansion—from temperature
T to temperature T (T < T ):
priate safety, health, and environmental practices and deter-
1 2 1 2
mine the applicability of regulatory limitations prior to use.
L 2 L
2 1
P 5 31001A
1.3 This international standard was developed in accor-
L
0
dance with internationally recognized principles on standard-
∆L
ization established in the Decision on Principles for the
5 31001A
L
0
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical where:
Barriers to Trade (TBT) Committee.
P = percent linear thermal expansion from temperature T
1
to T ,
2
2. Referenced Documents
L = sample length at T (T between 20 and 30°C),
0 0 0
2
2.1 ASTM Standards: L = sample length at T ,
1 1
L = sample length at T , and
E220Test Method for Calibration of Thermocouples By
2 2
A = instrument correction.
Comparison Techniques
E228Test Method for Linear Thermal Expansion of Solid
4. Significance and Use
Materials With a Push-Rod Dilatometer
4.1 Measurementofthermalexpansionisusefulforpredict-
E230/E230MSpecification for Temperature-Electromotive
ing stress within joined materials or single materials under
Force (emf) Tables for Standardized Thermocouples
conditions of changing or nonuniform temperature. It can also
E691Practice for Conducting an Interlaboratory Study to
serve as an indicator of phase composition or changes in
Determine the Precision of a Test Method
structure.
5. Apparatus
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC21onCeramic
Whitewares and Related Productsand is the direct responsibility of Subcommittee
5.1 Thermal Dilatometer:
C21.03 on Methods for Whitewares and Environmental Concerns.
5.1.1 General Description—A thermal dilatometer is an
Current edition approved Nov. 1, 2020. Published December 2020. Originally
apparatus that provides means for varying the temperature of a
approved in 1955. Last previous edition approved in 2016 as C372–94(2016).
DOI: 10.1520/C0372-94R20.
test specimen in a controlled manner, measuring the specimen
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
length,andmeasuringthetemperatureofthespecimenforeach
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
readingofspecimenlength.Thereareseveraldifferenttypesas
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. follows:
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C372 − 94 (2020)
NOTE 1—The sample must be cooled slowly over several hours to
5.1.1.1 Manual—Amanual dilatometer is one in which any
preserve structural integrity.
oralloftheabovearedonebymanualmeansandthecorrected
percent linear thermal expansion curve is plotted by hand.
6.2 For all samples, test specimens may be of any conve-
5.1.1.2 Recording—Arecording dilatometer is an apparatus nient length, provided the uniformity of the furnace has been
bywhichtheabovearerecordedbyinstrumentalmeansbutthe
determined over that length. The minimum thickness o
...