ASTM B877-96(2018)
(Test Method)Standard Test Method for Gross Defects and Mechanical Damage in Metallic Coatings by the Phosphomolybdic Acid (PMA) Method
Standard Test Method for Gross Defects and Mechanical Damage in Metallic Coatings by the Phosphomolybdic Acid (PMA) Method
SIGNIFICANCE AND USE
5.1 The primary purpose of the PMA test is to determine the presence of mechanical damage, wear through, and other gross defects in the coating. Most metallic coatings are intended to be protective, and the presence of gross defects indicates a serious reduction of such protection.
5.2 The protection afforded by well applied coatings may be diminished by improper handling following plating or as a result of wear or mechanical damage during testing or while in service. The PMA test can serve to indicate the existence of such damage.
5.3 This test is used to detect underplate and substrate metal exposed through normal wear during relative motions (mating of electrical contacts) or through mechanical damage. As such, it is a sensitive pass/fail test and, if properly performed, will rapidly detect wear through to base metals or scratches that enter the base metal layers.
5.4 This test is relatively insensitive to small pores. It is not designed to be a general porosity test and shall not be used as such. The detection of pores will depend upon their sizes and the length of time that the reagent remains a liquid.
5.5 This test cannot distinguish degrees of wear through or whether the wear through is to nickel or copper. Once base metal is exposed, the colored molybdenum complex is formed. While relatively small area defects (compared to the area of the droplet) may be seen at the bottom of the drop as tiny colored regions immediately after applying the PMA, any larger areas of exposed base metal will cause the entire droplet to turn dark instantly.
5.6 The PMA test also detects mechanical damage that exposes underplate and substrate metal. Such damage may occur in any postplating operation or even at the end of the plating operation. It can often occur in assembly operations where plated parts are assembled into larger units by mechanical equipment.
5.7 The PMA test identifies the locations of exposed base metal. The extent and location of these exposed...
SCOPE
1.1 This test standard covers equipment and methods for using phosphomolybdic acid (PMA) to detect gross defects and mechanical damage including wear through in metallic coatings of gold, silver, or palladium. These metals comprise the topmost metallic layers over substrates of nickel, copper, or copper alloys.
1.2 Recent reviews of porosity testing, which include those for gross defects, and testing methods can be found in the literature.2, 3 An ASTM guide to the selection of porosity and gross defect tests for electrodeposits and related metallic coatings is available as Guide B765. Other related porosity and gross defects test standards are Test Methods B735, B741, B798, B799, B809, and B866, Specifications B488, B679,and B689.
1.3 The values stated in SI units are the preferred units. Those in parentheses are for information only.
1.4 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.
1.5 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
Relations
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: B877 − 96 (Reapproved 2018)
Standard Test Method for
Gross Defects and Mechanical Damage in Metallic Coatings
1
by the Phosphomolybdic Acid (PMA) Method
This standard is issued under the fixed designation B877; 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 2. Referenced Documents
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1.1 This test standard covers equipment and methods for
2.1 ASTM Standards:
usingphosphomolybdicacid(PMA)todetectgrossdefectsand
B374Terminology Relating to Electroplating
mechanical damage including wear through in metallic coat-
B488Specification for Electrodeposited Coatings of Gold
ings of gold, silver, or palladium. These metals comprise the
for Engineering Uses
topmost metallic layers over substrates of nickel, copper, or
B542Terminology Relating to Electrical Contacts andTheir
copper alloys.
Use
1.2 Recent reviews of porosity testing, which include those
B679Specification for Electrodeposited Coatings of Palla-
for gross defects, and testing methods can be found in the
dium for Engineering Use
2,3
literature. An ASTM guide to the selection of porosity and
B689Specification for Electroplated Engineering Nickel
gross defect tests for electrodeposits and related metallic
Coatings
coatingsisavailableasGuideB765.Otherrelatedporosityand
B735Test Method for Porosity in Gold Coatings on Metal
gross defects test standards are Test Methods B735, B741,
Substrates by Nitric Acid Vapor
B798, B799, B809, and B866, Specifications B488, B679,and
B741Test Method for Porosity In Gold Coatings On Metal
B689. 5
Substrates By Paper Electrography (Withdrawn 2005)
1.3 The values stated in SI units are the preferred units. B765GuideforSelectionofPorosityandGrossDefectTests
Those in parentheses are for information only.
for Electrodeposits and Related Metallic Coatings
B798Test Method for Porosity in Gold or Palladium Coat-
1.4 This standard does not purport to address all of the
ings on Metal Substrates by Gel-Bulk Electrography
safety concerns, if any, associated with its use. It is the
B799Test Method for Porosity in Gold and Palladium
responsibility of the user of this standard to establish appro-
Coatings by Sulfurous Acid/Sulfur-Dioxide Vapor
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. B809Test Method for Porosity in Metallic Coatings by
1.5 This international standard was developed in accor- Humid Sulfur Vapor (“Flowers-of-Sulfur”)
dance with internationally recognized principles on standard- B866Test Method for Gross Defects and Mechanical Dam-
ization established in the Decision on Principles for the
age in Metallic Coatings by Polysulfide Immersion
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
3. Terminology
Barriers to Trade (TBT) Committee.
3.1 Definitions—Many terms in this test method are defined
in Terminology B374 or B542
1 3.2 Definitions of Terms Specific to This Standard:
ThistestmethodisunderthejurisdictionofASTMCommitteeB08onMetallic
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on
Test Methods.
Current edition approved Aug. 1, 2018. Published August 2018. Originally
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approvedin1996.Lastpreviouseditionapprovedin2013asB877–96(2013).DOI: For referenced ASTM standards, visit the ASTM website, www.astm.org, or
10.1520/B0877-96R18. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
2
Clarke,M.,“PorosityandPorosityTests,” Properties of Electrodeposits,ed.by Standards volume information, refer to the standard’s Document Summary page on
Sand, Leidheiser, and Ogburn, The Electrochemical Society, 1975, p. 122. the ASTM website.
3 5
Krumbein, S. J., “PorosityTesting of Contact Platings,”Trans. Connectors and The last approved version of this historical standard is referenced on
Interconnection Technology Symposium, Philadelphia, PA, October 1987, p. 47. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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B877 − 96 (2018)
3.2.1 base metal, n—any metal other than gold, silver, aqueous PMAsolution is applied to the spot in question using
platinum, palladium, iridium, or rhodium. Typical base metals an applicator. If it contacts base metals from exposed under-
used as underplates or substrates are copper, nickel, tin, lead,
...
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