ASTM B Standard Practice for Qualitative Adhesion Testing of Metallic Coatings. standard by ASTM International, 08/01/ View all product details. ASTM B quantifies various physical properties of metal coating substances such as gold, copper, silver and several others on their adhesion quality via. ASTM B STANDARD PRACTICE FOR QUALITATIVE ADHESION TESTING OF METALLIC COATINGS_建筑/土木_工程科技_专业资料。.
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A number in parentheses indicates the year of last reapproval. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense. No other units of measurement are included in this standard. 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. If more than one test is used, failure sstm pass any one test is considered unsatisfactory. In many instances, the end use of the coated article or its method of fabrication will suggest the technique that best represents functional requirements.
For example, an article that is to be subsequently formed would suggest a draw or a bend test; an article that is to be soldered or otherwise exposed to heat would suggest a heat-quench test. If a part requires baking or heat treating after plating, adhesion tests should be carried out after such posttreatment as well. These limitations are noted generally in the test descriptions and are summarized in Table 1 for certain metallic coatings.
Such adhesion is usually obtained if good electroplating practices are followed. This may be prying, hammering, bending, beating, heating, sawing, grinding, pulling, scribing, chiseling, or a combination of such treatments. If the coating peels,? These tests have varying degrees of severity; and one might serve to distinguish between satisfactory and unsatisfactory adhesion in a speci?
The choice for each situation must be determined. Because the results of tests in cases of marginal adhesion are subject to interpretation, agreement shall be reached on what is acceptable. If permitted, test panels shall be of the same material and have the same surface? The mandrel diameter should be four times the thickness of the sample.
Examine the deformed area visually under low magni?
ASTM B – ADHESION OF PLATINGS (EXCEPT DRAW TEST)
If the coating fractures or blisters, a sharp blade may be used to attempt to lift off the coating. Current edition approved April 1, Originally approved in Last previous edition approved in as B — 97 Such cracks may or may asrm propagate into the substrate.
In either case, cracks are not indicative of poor adhesion unless the coating can be peeled back with a sharp instrument. Examine the region at low magni? Prying with a sharp blade will indicate unsatisfactory adhesion by asym off of the coating. A suitable tool is a steel rod 6 mm in diameter with a smooth hemispherical end.
The pressure shall be sufficient to burnish the coating at each stroke but not so great as to dig into it. Blisters, lifting, or peeling should not develop. Generally, thick deposits cannot be evaluated satisfactorily. Alternatively the chisel may be placed in back of an overhang area of the coating aetm at a coatingsubstrate interface exposed by sectioning the article with a saw.
ASTM B STANDARD PRACTICE FOR QUALITATIVE ADHESION TESTING OF METALLIC COATINGS_百度文库
A knife may be substituted for the chisel with or without hammering or light tapping. If it is possible to remove the deposit, the adhesion is not satisfactory. Soft or thin coatings cannot be evaluated for adhesion by this method. The adhesion of the coating may be observed directly or evaluated further by techniques described in Section 5 for detachment from the substrate.
If there is peeling or? Lifting b751 peeling is evidence of unsatisfactory adhesion. Vol 22,p. A hack saw may be substituted for the wheel, making sure to saw in the direction that tends to separate the coating from the substrate.
Coatings and substrates that are sensitive to oxidation should be heated in an inert or reducing atmosphere or a suitable liquid. Then quench the part in water or other suitable liquid at room temperature.
Blisters may erupt during the heat and quench test when plating solution is entrapped in substrate surface pits or pores which are bridged by the deposit.
If the deposited coating cannot be peeled or lifted from the substrate in an area adjacent to the blister sthe appearance of blisters should not be interpreted as evidence of inferior adhesion. In some cases, a brittle layer may be created by the materials involved causing peeling as a result of fracture rather than poor adhesion. This would not give a correct ast of the as-plated bond strength.
Reproducible atsm are more easily obtained by the use of a suitably modi? The severity of the test may be altered by changing the load and diameter of the ball. Exfoliation or blisters in and around indentations are evidence of inadequate adhesion. Soft and ductile coatings are generally not suited for evaluation. Adhesive-backed tape may be sstm as a possible alternative. Heat curing of the adhesive may be used, keeping in mind considerations noted in 9.
For reproducible results, the rate of pull, the thickness and width of the strip, and deposit thickness must be standardized. A quantitative analysis of the factors b5771 has been published.
Supporting the material on a ring about 2. In scribing the lines, use sufficient pressure to cut through the coating to the substrate in a single stroke. If any portion of coating between the lines breaks away from the substrate, the adhesion is inadequate.
Make sure that any loose coating particles from scribing do not remain. The adhesion is not adequate if the tape has deposit adhering to it that comes from the area between the scribed lines. Deposit continuous to the scribed lines is not considered. The tape shall be wide b751 to cover three or more parallel lines of the scribed area. Precision and Bias Users of this standard are expressly adtm that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
ASTM B571 Adhesion Metals Coating Test Equipment
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every? Your comments are invited either for revision of this standard or for additional standards and should be b5711 to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at astj address shown below.
Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm.