ASTM C539-84(2006)
(Test Method)Standard Test Method for Linear Thermal Expansion of Porcelain Enamel and Glaze Frits and Ceramic Whiteware Materials by Interferometric Method
Standard Test Method for Linear Thermal Expansion of Porcelain Enamel and Glaze Frits and Ceramic Whiteware Materials by Interferometric Method
SIGNIFICANCE AND USE
This test method defines the thermal expansion of porcelain enamel and glaze frits by the interferometric method. This determination is critical in avoiding crazing (cracking) of these glass coatings due to mismatching of the thermal expansion between the coating and substrate materials.
SCOPE
1.1 This test method covers the interferometric determination of linear thermal expansion of premelted frits (porcelain enamel and glaze) and fired ceramic whiteware materials at temperatures lower than 1000°C (1830°F).
1.2 This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:C539–84 (Reapproved 2006)
Standard Test Method for
Linear Thermal Expansion of Porcelain Enamel and Glaze
Frits and Ceramic Whiteware Materials by Interferometric
Method
This standard is issued under the fixed designation C539; 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 4.1.2 Fireclay Crucible, 102 mm (4 in.) in diameter.
4.1.3 Rotating Abrasive Grinding Wheel (a silicon carbide
1.1 This test method covers the interferometric determina-
type is satisfactory).
tion of linear thermal expansion of premelted frits (porcelain
4.2 Micrometer Calipers, having a sensitivity such that the
enamel and glaze) and fired ceramic whiteware materials at
index can be read to 0.002 mm (0.0001 in.).
temperatures lower than 1000°C (1830°F).
4.3 Measuring Apparatus, consisting of fused silica inter-
1.2 This standard does not purport to address all of the
ferometer plates, viewing apparatus, an electric furnace and
safety concerns, if any, associated with its use. It is the
control, potentiometer, pyrometer, and a suitable monochro-
responsibility of the user of this standard to establish appro-
matic light source of known wavelength.
priate safety and health practices and determine the applica-
4.3.1 Furnace—The furnace shall be a vertical electric tube
bility of regulatory limitations prior to use.
furnace controlled by rheostat or other means so the heating
2. Referenced Documents rate of the furnace can be readily duplicated from room
temperature to 1000°C (1830°F). The heating rate shall not
2.1 ASTM Standards:
exceed 3°C (5.5°F)/min.
E289 Test Method for Linear Thermal Expansion of Rigid
4.3.2 Temperature Measuring Instrument— A calibrated
Solids with Interferometry
platinum versus platinum-rhodium thermocouple (or a
3. Significance and Use
Chromel versus Alumel thermocouple if it is frequently cali-
brated) in conjunction with a potentiometer shall be used. The
3.1 This test method defines the thermal expansion of
potentiometer shall be capable of being read to 2°C (4°F) and
porcelain enamel and glaze frits by the interferometric method.
shall have automatic compensation for the temperature of the
This determination is critical in avoiding crazing (cracking) of
reference junction, or the reference junction shall be held at
these glass coatings due to mismatching of the thermal
0°C (32°F) by means of an ice bath.
expansion between the coating and substrate materials.
5. Test Specimens
4. Apparatus
5.1 For frit samples, three test specimens shall be prepared
4.1 Sample Preparation Equipment:
as follows:
4.1.1 Glazed Porcelain Crucible, No. 0.
5.1.1 Fill a No. 0 glazed porcelain crucible with frit, place
the filled crucible inside a 102-mm (4-in.) diameter fireclay
This test method is under the jurisdiction ofASTM Committee B08 on Metallic
crucible partly filled with silica, and work the small crucible
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.12 on
down into the silica until approximately 75 % of the small
Materials for Porcelain Enamel and Ceramic-Metal Systems.
Current edition approved April 1, 2006. Published April 2006. Originally crucible is below the level of the silica.
approved in 1964. Last previous edition approved in 2000 as C539 – 84 (2000).
5.1.2 Place the crucible assembly into a furnace at a
DOI: 10.1520/C0539-84R06.
temperaturehighenoughtojustmeltthemass.Holdfor15min
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
after the frit has reached the furnace temperature.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
5.1.3 Remove the crucible, rapidly transfer it to another
the ASTM website.
furnace that is at the frit firing temperature, and cool in the
An example of suitable test equipment and an inferometric method may be
furnace at a rate not to exceed 60°C (110°F)/h.
found in the paper by Merritt, G. E., “The Interference Method of Measuring
5.1.4 Break the small crucible open and break up the
Thermal Expansion,” Journal of Research, National Institute of Standards and
Technology, Vol 10, No. 1, January 1933, p. 59 (RP 515).
vitreous mass. Select six fragments from the interior of the
A description of a permissible automatic fringe recording device may be found
mass (to avoid side portions diluted by the ceramic crucible)
in the paper by Saunders, J. B., “An Apparatus for Photographing Interference
having minimum conical dimensions of 3 mm ( ⁄8 in.) at the
Phenomenon,” Journal of Research, National Institute for Standards and Technol-
ogy, Vol 35, No. 3, September 1945, p. 157 (RP 1668). base and 6 mm ( ⁄4 in.) high.
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C539–84 (2006)
5.2 For fired samples, break and select six samples having fewer or more fringes are present, adjust the cone heights. In
minimum conical dimensions of 3 mm ( ⁄8 in.) at the base and some cases, mere tapping of the specimen assembly will
6mm( ⁄4 in.) in height. For all samples, grind the base of the produce the correct number of fringes. Carefully measure and
flatconesandcementtheflatconebasetotheflatendofaglass record the height of each cone. Upon achieving the proper
rod with heated sealing wax. Grind the piece to a finished cone number of fringes, place the refractory ring cover on the
by rotating the rod while the piece is held against a rotating crucible and recheck for fringes.
abrasive wheel (a silicon carbide type is satisfactory). 7.3 Without rotating the crucible, gently lower it into the
5.2.1 When a reasonably symmetrical cone with a rounded furnace and onto the bottom support so the thermocouple rests
tip is obtained, remove it from the rod by heating the wax or by at the bottom of the crucible. Cover the top of the furnace with
pressure with the fingertips. Remove all sealing wax with a a quartz plate.
knife blade or abrasive paper. 7.4 Rotate the telescope and check the fringe pattern. If
5.2.2 The test cone height may be of the order of 4.8 mm excessive glare or poor contrast are present, adjust by moving
( ⁄16 in.). These bases must be smooth and flat. Use No. 0 the quartz cover, moving the light source, or releveling the
metallurgical paper to approach the desired figure and then use telescope.
successively finer papers until the final reduction is made with
NOTE 1—Removal of the telescope eyepiece should reveal a bright dot,
a No. 3/0 paper.
which is the true image. This must be in the field or no fringes will be
seen. If this bright dot of the true image is not seen when the eyepiece is
6. Calibration of Furnace
removed, a great deal of trial and error adjustment of the telescope tripod
must be made.Anumber of false images may also be present. These must
6.1 Using the following procedure, calibrate the furnace
be sorted out by inserting the eyepiece and checking to see if fringes are
controls to obtain a heating rate of 3°C (5.5°F)/min:
present. If no fringes are seen, the bright dot is a false image.
6.1.1 Prepare three conical spacers closely approximating
7.5 Standardize the potentiometer if necessary and set the
the dimensions of the final test pieces described in Section 5.
potentiometer or other temperature measuring instrument to
These spacers shall be ground from fragments of refractory
38°C (100°F).
ceramic known to have a softening temperature in excess of
7.6 Slowly heat the furnace to 38°C (100°F). Center the
1000°C (1830°F).
cross hair of the telescope upon any convenient fringe and
6.1.2 Assemble the upper and lower interferometer plates
record the temperature corresponding to each fifth fringe.
with three refractory spacers as described in Section 7, except
7.7 Continue heating th
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