ASTM C554-93(2006)

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Designation:C554–93 (Reapproved 2006)
Standard Test Method for
Crazing Resistance of Fired Glazed Ceramic Whitewares by
a Thermal Shock Method
This standard is issued under the fixed designation C554; 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 residual stresses from the firing that bonded the glaze to the
body. In addition, whitewares are increasingly subjected to
1.1 This test method covers the determination of the resis-
thermal stresses in service. Hence, an important use criterion
tance to crazing of fired, glazed, ceramic whitewares when
for a glazed whiteware is adequate resistance to repeated
stresses residual after glost firing may cause a tendency to
abrupt thermal changes. In most cases, the result of inadequate
craze, such stresses being induced by factors other than
resistance to thermal shock is the appearance of a craze pattern
moisture expansion.
in the glaze. This craze pattern is visible by inspection with
1.2 This test is not intended to induce moisture expansion,
oblique lighting and application of a suitable ink or dye.
which fact should be kept in mind if the materials to be
3.2 This test method is applicable to vitreous whitewares
evaluated may exhibit moisture expansion.
that have negligible crazing as a result of moisture expansion.
NOTE 1—Test Method C424 covers a method for determining resis-
For nonvitreous and semivitreous bodies, refer to Test Method
tance to crazing induced by moisture expansion. Its use is generally
C424.
confined to testing nonvitreous and semivitreous ceramic whitewares
because these products may be subject to such expansion. For whitewares
4. Apparatus
with negligible moisture expansion (such as vitreous and impervious
4.1 Oven—An oven suitable to operate in the range 250 to
ware), the thermal shock method described herein is generally to be
preferred.
450°F (121 to 232°C) while holding the required temperatures
within 65°F (63°C) and being capable of recovering tempera-
1.3 This standard does not purport to address all of the
ture within 20 min after being loaded with the desired number
safety concerns, if any, associated with its use. It is the
of specimen(s).
responsibility of the user of this standard to establish appro-
4.2 Water Containers—Containers to hold water at 68 6
priate safety and health practices and determine the applica-
5°F (20 6 3°C) before quenching; the capacity of the contain-
bility of regulatory limitations prior to use. For a specific
ers shall be large enough so that the water temperature does not
hazard statement, see Warning in 6.3.
exceed 85°F (29°C) after quenching a single specimen. Two or
1.4 The values stated in inch-pound units are to be regarded
more specimens may be quenched simultaneously in a single
as the standard. The values in parentheses are for information
container provided they do not overlap on the bottom of the
only.
container and provided that the water temperature does not
2. Referenced Documents
exceed 85°F (29°C) after quenching. As a general rule, it will
be found that 10 cm of water/g of ware, or 1 gal of water/lb
2.1 ASTM Standards:
of ware will be adequate to keep the temperature within the
C424 Test Method for Crazing Resistance of Fired Glazed
required limits. There shall be enough containers to quench all
Whitewares by Autoclave Treatment
the specimens loaded in the oven. The containers shall be deep
3. Significance and Use
enough so that at least ⁄2 in. (13 mm) of water will cover the
quenched specimen(s).
3.1 Unless there is a proper match between the expansions
of the glaze and the body, all glazed whitewares may contain
5. Test Specimens
5.1 The specimen(s) shall preferably be whole pieces of
This test method is under the jurisdiction ofASTM Committee C21 on Ceramic
ware;cutorbrokenspecimen(s)shallbeusedonlywhenwhole
Whitewares and Related Products and is the direct responsibility of Subcommittee
pieces are impractical or impossible to test. If the specimen(s)
C21.03 on Methods for Whitewares and Environmental Concerns.
Current edition approved Feb. 15, 2006. Published Febraury 2006. Originally are cut or broken from whole ware, they shall be selected so as
approved in 1964. Last previous edition approved in 1999 as C554 – 93 (1999).
to be representative of the item to be tested. In cutting or
DOI: 10.1520/C0554-93R06.
breaking specimen(s), cracks may be induced, therefore, bro-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ken or cut specimens shall be inspected for cracks by oblique
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
lighting and application of a suitable ink or dye before the test.
the ASTM website.
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