ASTM B571-97 pdf free.Standard Practice for Qualitative Adhesion Testing of Metallic Coatings.
9.2 Flaking or peeling of the deposit is evidence of unsat-isfactory adhesion. Blisters may erupt during the heat andquench test when plating solution is entrapped in substratesurface pits or pores which are bridged by the deposit. If thedeposited coating cannot be peeled or lifted from the substratein an area adjacent to the blister(s), the appearance of blistersshould not be interpreted as evidence of inferior adhesion.9.3 Diffusion and subsequent alloying of metals may im-prove the bond strength of electrodeposits. In some cases， abrittle layer may be created by the materials involved causingpeeling as a result of fracture rather than poor adhesion. Thiswould not give a correct indication of the as-plated bondstrength.
This test is nondestructive if the procedure does notcreate unwanted effects on parts.
Use a hammer or impact device coupled with a suitablebacking block to support the article to be tested to deform thesample. Reproducible results are more easily obtained by theuse of a suitably modified impact tester where the force isreproducible and the impact head contour is in the form of aS-mm diameter ball，shock loaded by a falling weight orswinging pendulum weight. The severity of the test may bealtered by changing the load and diameter of the ball. Exfolia-tion or blisters in and around indentations are evidence ofinadequate adhesion.
This test is sometimes difficult to interpret. Soft andductile coatings are generally not suited for evaluation.
Bond a strip of steel or brass about 1.5 mm thick and20 mm wide by solder or suitable adhesive to a properly flatarea of the coated surface of the article. Adhesive-backed tapemay be considered as a possible alternative. Heat curing of theadhesive may be used, keeping in mind considerations noted in9.3. The angle of pull shall be 90to the surface. Forreproducible results, the rate of pull, the thickness and width ofthe strip, and deposit thickness must be standardized.Failure inthe coating/substrate interface is evidence of inadequate adhe-sion.
The tensile and shear strengths of adhesives andsolders limit the range of adhesion strengths that can beevaluated. A quantitative analysis of the factors involved hasbeen published.ASTM B571 pdf download.