Parts are rack or barrel plated to ASTM B standard thicknesses from ” to “, depending on the base metal and application. Pure % tin is. Designation: B – 97 (Reapproved )e1 Standard Speci?cation for Electrodeposited Coatings of Tin1 This standard is issued under the. ASTM B Standard Specification for Electrodeposited Coatings of Tin.
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ASTM B – 13 Standard Specification for Electrodeposited Coatings of Tin
asm A number in parentheses indicates the year of last reapproval. Blackening at pores will be evidence of porosity. Practically all of the following methods take into account the chief cause of tin whiskering, which is the presence of stresses in the tin coating 8: Practice B may be consulted to determine the most appropriate test method.
Class A Minimum Thickness 2.
Such acceptance or pass-fail criteria, if required, should be part of the product speci? Examination of 43 magni? For some applications, this requirement may be relaxed to allow for a small number of such defects per unit areaespecially if they are outside of or on the periphery of signi?
These should be taken into account when designing for special applications. The appearance shall be uniform throughout, insofar as the basis metal will permit. If they do not, Test Method B identi?
This specification covers the requirements for electrodeposited tin coatings applied to metallic articles to provide a low contact resistance surface, to protect against corrosion, to facilitate soldering, to provide anti-galling properties, and to be a stop-off coating in the nitriding of high-strength steels.
Flow-brightened coatings shall be free of dewetted areas and beads.
Moderate exposure conditions, usually indoors, but more severe than Class B. However, all matte baths except for stannate baths do require the addition of grainre?
Black spots asgm lines are evidence of mechanical damage or gross defects. The buyer and seller may agree on the plan or plans to be used. If special test specimens are used 7. There needs to be sufficient free tin below the oxide layer in order for this to occur, because the intermetallic compounds formed from tin and the basis metal will not react in this way 7.
Corrosion can be expected at discontinuities in the coating such as pores due to galvanic couples formed between the tin and the underlying metal through the discontinuities, especially in humid atmospheres. Suspend the test specimens above this solution on nonmetallic supports, with the surfaces of the specimens not less than 25 mm 1 in.
MIL-T-10727 vs. ASTM B545
These whiskers frequently are approximately 2. The values given in parentheses are for information only. The coating should adhere to the basis metal when subjected to the agreed test;?
The size of the sample and the criteria of compliance are determined by the application of statistics. The purchaser shall specify whether the tested articles are to receive an arti?
A suitable burnishing implement is a copper or steel disk used edgewise and broadside. The values given in parentheses are for information only. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard.
The surface appearance types are matte tin electrodeposits, bright tin electrodeposits, and flow-brightened electrodeposits. Astmm provide corrosion and tarnish resistance where greater thicknesses may be detrimental to the mechanical operation of the product for example, small electrical spring contacts and relays.
The mechanical 5b45 of the molten solder and tin? Poor adhesion will be shown by the appearance of a loose blister that grows as rubbing is continued.
This abstract is a brief summary of the referenced standard. Severe service, including exposure b455 dampness and mild corrosion from moderate industrial environments.
Some tin coatings, especially of bright tin, may show? With such b55 coatings, a diffusion barrier of nickel may be advantageous, although users should also consider the use of thicker coatings when solderability must be maintained over a period of years 6.
The maximum thickness for?