ASTM B490-09(2021)

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: B490 − 09 (Reapproved 2021)
Standard Practice for
Micrometer Bend Test for Ductility of Electrodeposits
This standard is issued under the fixed designation B490; 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. Summary of Practice
1.1 This practice describes a procedure for measuring the 3.1 This practice consists of measuring the bend of a foil
ductility of electrodeposited foils. held between the jaws of a micrometer; these are closed until
fracture or cracks appear.
1.2 This practice is suitable only for the evaluation of
electrodeposits having low ductility.
4. Significance and Use
1.3 The obtained ductility values must only be considered
4.1 This practice is useful as one method of controlling
semi-quantitative because this test has a significant operator
someelectroplatingsolutions.Itservestoindicatethepresence
dependence.
of contamination or some other adverse condition.
1.4 This practice is best used for in-house process control
4.2 Ductility measurements are of particular value when
where measurements are always made by the same operator.A
electroplated parts are to be subjected to moderate stress such
change in ductility value can be used as an indication of
as that involved in bolting an electroplated bumper to an
possible changes in the electroplating solution.
automobile or when exposed to a wide range of fluctuating
1.5 The values stated in SI units are to be regarded as
temperatures (thermal shock).
standard. No other units of measurement are included in this
standard. 5. Apparatus
1.6 This standard does not purport to address all of the
5.1 Micrometer, 25-mm with flat jaws to measure the
safety concerns, if any, associated with its use. It is the thickness and to compress the foil.
responsibility of the user of this standard to establish appro-
5.2 Toolssuchasahandorpowershear,grindingwheel,file
priate safety, health, and environmental practices and deter-
or hack saw, to initiate separation of the foil from the basis
mine the applicability of regulatory limitations prior to use.
metal.
1.7 This international standard was developed in accor-
5.3 Pair of Sharp Scissors to cut the test specimens.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
6. Test Specimens
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical 6.1 An electrodeposit shall be prepared using a basis metal
Barriers to Trade (TBT) Committee. with a smooth surface from which the electrodeposit can be
readilyseparated.Properpreparationofthesurfacefromwhich
2. Referenced Documents
the foil must be separated undamaged is critical. The deposit
shall be electroplated at an average current density and under
2.1 ASTM Standards:
conditions (agitation, temperature, etc.) approximating those
B456Specification for Electrodeposited Coatings of Copper
used on parts electroplated in the solution being tested. The
Plus Nickel Plus Chromium and Nickel Plus Chromium
depositthicknessshallbe25-30µm.Thepanelsarepreparedas
in 6.2.
This practice is under the jurisdiction of ASTM Committee B08 on Metallic
6.2 The test panel must be properly passivated before
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on
Test Methods.
plating to allow for separation of the subsequent deposit.
Current edition approved April 1, 2021. Published May 2021. Originally
Stainless steel, brass or nickel dipped in a chromic acid
approvedin1968.Lastpreviouseditionapprovedin2014asB490–09(2014).DOI:
solution (see Note 1) for approximately 1 minute can be used
10.1520/B0490-09R21.
as the basis metal. The panel should be properly rinsed before
For a discussion of this test see Mohrnheim, A. F., “The Bend Test for
Measuring the Strain Limit of Surfaces,” Plating, Vol 50, 1963, pp. 1094–1099.
plating. Entering the solution with current on is recommended
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
to prevent activation of the basis metal. When testing nickel
contactASTM Customer Service at service@astm.org. ForAnnual Book ofASTM
deposits, other than rinsing, no post treatments shall be used.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. An alternative method is described in Note 2.
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B490 − 09 (2021)
NOTE 1—For convenience, an ordinary hexavalent chromium electro- jaws the force may not be uniformly distributed, which could lead to
plating solution can be used for preparing th
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