ASTM B490-92(2003)

Standard Practice for Micrometer Bend Test for Ductility of Electrodeposits

SIGNIFICANCE AND USE
This practice is useful as one method of controlling some electroplating solutions. It serves to indicate the presence of contamination or some other adverse condition.
Ductility measurements are of particular value when electroplated parts are to be subjected to moderate stress such as that involved in bolting an electroplated bumper to an automobile.
Note 1—The foils used in this practice are typically 25 to 40 μm thick. Foils in this thickness range do not have the same properties as bulk metal. For example, a nickel electrodeposit 0.5 mm thick, prepared in purified bright nickel electroplating solutions for which this test is being used, had less than 3 % elongation in a tension test, and could not be bent to a 90° angle without complete fracture. However, foils 25 to 40 μm thick, electroplated at the same time, had micrometer ductility values in the 10 to 25 % range.
SCOPE
1.1 This practice describes a procedure for measuring the ductility of electrodeposited foils.
1.2 This practice is suitable only for the evaluation of electrodeposits having low ductility.
1.3 The obtained ductility values must only be considered semi-quantitative because this test has a significant operator dependence.
1.4 This practice is best used for in-house process control where measurements are always made by the same operator. A change in ductility value can be used as an indication of possible changes in the electroplating solution.
1.5 This standard does not purport to address the safety problems, 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

• Status: Historical
• Publication Date: 30-Sep-2003
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.10 - Test Methods

Relations

• Replaces: ASTM B490-92(1998) - Standard Practice for Micrometer Bend Test for Ductility of Electrodeposits
• Effective Date: 01-Oct-2003
• Replaced By: ASTM B490-92(2008)e1 - Standard Practice for Micrometer Bend Test for Ductility of Electrodeposits
• Effective Date: 01-Apr-2008
• Referred By: ASTM B832-93(2018) - Standard Guide for Electroforming with Nickel and Copper
• Effective Date: 01-Oct-2003
• Referred By: ASTM B456-17(2022) - Standard Specification for Electrodeposited Coatings of Copper Plus Nickel Plus<brk/> Chromium and Nickel Plus Chromium
• Effective Date: 01-Oct-2003

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:B490–92(Reapproved 2003)
Standard Practice for
Micrometer Bend Test for Ductility of Electrodeposits
This standard is issued under the fixed designation B 490; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4.2 Ductility measurements are of particular value when
electroplated parts are to be subjected to moderate stress such
1.1 This practice describes a procedure for measuring the
as that involved in bolting an electroplated bumper to an
ductility of electrodeposited foils.
automobile.
1.2 This practice is suitable only for the evaluation of
electrodeposits having low ductility.
NOTE 1—The foils used in this practice are typically 25 to 40 µm thick.
1.3 The obtained ductility values must only be considered
Foilsinthisthicknessrangedonothavethesamepropertiesasbulkmetal.
For example, a nickel electrodeposit 0.5 mm thick, prepared in purified
semi-quantitative because this test has a significant operator
bright nickel electroplating solutions for which this test is being used, had
dependence.
less than 3 % elongation in a tension test, and could not be bent to a 90°
1.4 This practice is best used for in-house process control
angle without complete fracture. However, foils 25 to 40 µm thick,
where measurements are always made by the same operator.A
electroplated at the same time, had micrometer ductility values in the 10
change in ductility value can be used as an indication of
to 25 % range.
possible changes in the electroplating solution.
5. Apparatus
1.5 This standard does not purport to address the safety
problems, if any, associated with its use. It is the responsibility
5.1 Micrometer, 25-mm with flat jaws to measure the
of the user of this standard to establish appropriate safety and
thickness and to compress the foil.
health practices and determine the applicability of regulatory
5.2 Hand or Power Shear, grinding wheel, or hack saw, to
limitations prior to use.
trimtheedgesoftheelectroplatedpanelandtoseparatethefoil
from the basis metal.
2. Referenced Documents
5.3 Pair of Sharp Scissors to cut the test specimens.
2.1 ASTM Standards:
6. Test Specimens
B 177 Guide for Engineering Chromium Electroplating
6.1 An electrodeposit shall be prepared using a basis metal
3. Summary of Practice
with a smooth surface from which the electrodeposit can be
3.1 This practice consists of measuring the bend of a foil
readily separated.Astainless steel or nickel electroplated steel
held between the jaws of a micrometer; these are closed until
panel may be used for this purpose, prepared as in 6.2.
fracture or cracks appear.
6.2 Apieceofcold-rolledsteel,ofanyconvenientsize,such
as 100 by 150 mm, shall be properly cleaned, acid dipped, and
4. Significance and Use
electroplated with approximately 7.5 µm of nickel. After
4.1 This practice is useful as one method of controlling
rinsing, the specimen shall be cleaned anodically for 15 s in a
some electroplating solutions. It serves to indicate the presence
hot alkaline cleaner, rinsed, acid dipped in about 1 N sulfuric
of contamination or some other adverse condition.
acid (about 27 mLof concentrated sulfuric acid added to about
900 mL of cold water, mixed, and diluted with cold water to 1
L), and immediately placed in the electroplating solution of the
This practice is under the jurisdiction of ASTM Committee B08 on Metallic
metal to be tested.An electrodeposit 25 to 40 µm thick shall be
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on
Test Methods. electroplated on the prepared surface. The deposit shall be
Current edition approved Oct. 1, 2003. Published October 2003. Originally
plated at an average current density and under conditions
approved in 1968. Last previous edition approved in 1998 as B 490 – 92 (1998).
(agitation,temperature,etc.)approximatingthoseusedonparts
For a discussion of this test see Mohrnheim, A. F., “The Bend Test for
plated in the solution being tested.
Measuring the Strain Limit of Surfaces,” Plating, Vol 50, 1963, pp. 1094–1099.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
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Standards volume information, refer to the standard’s Document Summary page on
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