ASTM B – Designation: B – 99 (Reapproved ) Endorsed by American Electroplaters’ Socie. Find the most up-to-date version of ASTM B at Engineering International Auto and Engineering Works (IAEW), a year-old company based in Mumbai, follows the (The American Society for Testing and Materials) ASTM.
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ASTM-B | Standard Guide for Cleaning Metals Prior to Electroplating | Document Center, Inc.
Criteria of Cleanliness 8. One procedure involves scrubbing with pumice and then comparing the surface produced by this method with that produced under production conditions. For more h322 safety precautionary statements see Sections 11 and Special low-foaming surface-active agents are generally used. Part III —Final electrocleaning, to remove trace solids and especially adherent impurities. Good housekeeping is desirable to avoid bacterial contamination of emulsion cleaners.
It can be accurately stated, however, that many electroplating troubles can be traced to faulty cleaning. The common electroplates applied are usually copper, nickel, and chromium for decorative and functional uses.
The use of clean gloves should be mandatory after buffing or polishing to avoid?
These stages are discussed in three parts:. This is true of electrocleaners as well as soak or spray cleaners.
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The softness and surface? Prolonged storage or drying of emulsion drawing compounds after metal working should be avoided so that slimy water-in-oil emulsions do not form. Care must be taken to avoid redeposition of the soil as parts exit from the cleaner.
Too high a pH will result in lowering of the bacteria action, and oil will be built-up. These stages are discussed in three parts: It is not effective on metallic salts, scale, carbon deposits, many inorganic soldering or welding? Often, depending largely on the amount and type of soil on the astm b as astm b, one or more of these stages may be eliminated or modified.
ASTM B322 – 99(2014)
Part I —Precleaning use of a solvent, emulsion, or alkaline spray to remove the bulk of the soil. Alkaline cleaners vary in this respect; much depends on the amount of soil present on the work being cleaned. Selection of a free-rinsing cleaner may require some sacri?
Sodium hydroxide alone could impart this property, but it lacks the detergent action to remove oils, greases, and solid particle soils.
The chemical activity of the metal is an important and determining factor in cleaner selection. The choice of these procedures must be based on a knowledge of the metals to be cleaned and of the soils to be removed. The cleaner should be buffered to have a high tolerance for acidic soils.
This action, plus subsequent acid dip, before electroplating, removes disturbed metal surfaces and promotes better adhesion.
Combining these with hand brushing is excellent but does not lend itself to production conditions. The organic surface-active agents chosen should not be decomposed into tarry residues by heat, high alkalinity, or oxidation at anodes. It is not meant to apply to every speci?
In cathodic cleaning, little or no tarnish or attach of nonferrous metal occurs. The effective life of a cleaning bath must be estimated and baths discarded when exhausted. Air sparging also improves overall cleaning efficiency by promoting transfer of oil and grease particles from part surface into the cleaning bb322. Typically, optimum pH range for these types of cleaning systems is 8.
This involves visual observation after a? Boiler condensate may also be used advantageously. Nature of the Soil 3. Because most experience and knowledge in cleaning have been obtained by suppliers of proprietary processes and aetm, these sources should be consulted before setting up a cleaning process.
In certain circumstances, especially with materials used in the electronic industry, such electroplating defects may arise from other factors as well.
Part I —Precleaning use of a solvent, emulsion, or alkaline spray to remove the bulk of the soil. Since agitation is important to good astmm, the power-spray cleaners?
ASTM B – 99() – Standard Guide for Cleaning Metals Prior to Electroplating
The cleaners usually contain surface-active, soap-like materials which foam if asmt vigorously. Part II —Intermediate alkaline cleaning. This time is shortened if agitation is vigorous, temperatures high, and concentration high. Although agitation is better than in some cleaning, control is frequently not as good. With some cleaners, adequate rinsing is difficult to obtain after the cleaner has dried on the work. A cleaner may be very effective for one group of soils, yet poor for other adtm.
Zinc die castings have surfaces that require special care because of sensitivity to attack by cleaning solutions. Without air during operation, anerobic axtm are produced and the cleaner will take on a noticeable, unpleasant odor. With die castings, care must be exercised to avoid cutting through the surface by excessive buffing.