ASTM B281-2019 pdf free download

ASTM B281-2019 pdf free download.Standard Practice for Preparation of Copper and Copper-Base Alloys for Electroplating and Conversion Coatings
1. Scope
1.1 This practice is intended to serve as a guide for the proper preparation of copper and its alloys for electroplating and conversion coating. This practice is also suitable for use before autocatalytic plating. Only alloys containing at least 50 mass % copper are considered within the scope ofthis practice. 1.2 The wide variety ofmethods ofmechanical finishing are not considered strictly as preparation for electroplating or conversion coating and consequently are described only briefly. 1.3 Details of electroplating and subsequent treatments for applying conversion coatings are not within the scope of this practice. 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 appro- priate safety, health, and environmental practices and deter- mine the applicability of regulatory limitations prior to use. For a specific hazard statement, see 6.5.2. 1.5 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Significance and Use
3.1 The proper preparation of copper and copper alloy surfaces for electroplating, conversion coating, or autocatalytic plating is often critical to the performance of the coatings. 3.2 This practice outlines procedures required to produce satisfactory coatings on surfaces of copper and copper alloy surfaces.
4. Process Chemicals
4.1 All process chemicals are of technical grade or better. Acid solutions are prepared from grade chemicals as listed in Appendix X1. 4.2 Purity of Water—High quality water is not normally required to make up and maintain the solutions utilized in this practice. If reused or recycled water from waste treatment processes or from other in-plant sources is to be used, it should be relatively free of chromium salts, oil, wetting agents, or insoluble materials. Excessively hard water can decrease the life and performance of many cleaning solutions and make parts more difficult to rinse completely.
5. General Considerations
5.1 Removal of Oxides—Oxides can be removed from as fabricated, annealed, or heat-treated alloys by abrasive meth- ods such as tumbling, burnishing, and emery set-up wheel polishing and by chemical methods, such as deoxidizing solutions, bright dips, and cyanide dips. The choice of method is dependent on the resultant surface finish required, amount of oxide to be removed, and the end-use properties of the article finished.5.2 Castings andForgings—Castings and forgings requiring abrasive methods to produce a desired surface finish do not necessarily need pickling or bright dipping. If pickled, bright dipped, or deoxidized, however, castings and other porous parts should be thoroughly rinsed between operations to avoid or minimize staining or stain spots. Castings or forgings processed in solutions containing wetting agents, which are in many proprietary products or which may be added by the individual, usually require greater care in rinsing. 5.3 Stampings and Drawn Products—Stampings and drawn work follow the same rule as castings and forgings except, for economy considerations, it may be advisable to pickle or deoxidize before abrasive finishing ifheavy oxides are present. 5.4 Cold-Headed and Progressive Die Products—Cold- headed products and progressive die products often require relief annealing to avoid subsequent season cracking. 5.5 Screw Machine Products—Screw machine products may be readily electroplated with only mild cleaning and acid dipping as they are produced from the machines. Abrasive methods may be applied as appropriate before cleaning and acid dipping.