Metal Finishing Guide Book

2011-2012 Surface Finishing Guidebook

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Bath Type P-salt/sulfamate Pd(NH3 )2 (NO2 )2 salt Parameters Pd metal Analytical Method AA, ICP, spectrophotometry Ammonia sulfamate NA Ammonia hydroxide pH electrode Pd metal Palladosamine chloride Pd(NH3 )4 Cl2 Ammonia chloride Pd metal Palladium chloride PdCl2 Ammonia chloride Hydrochloric acid Pd-Ni alloy (80/20) Pd-Co alloy (80/20) Lead metal Nickel metal Ammonia chloride Table 5: Analysis of Pd, Pd-Ni, and Pd-Co Baths ANALYTICAL TECHNIQUES It is important to review the flow sheet of a given plating process (rack, barrel, reel to reel) and understand the sequence of the operation. This guides the operator to prepare for a safe start by analyzing the plating baths needed in the process. Most job shops use traditional wet methods. The commercial use of instrumental techniques is limited due to complex oper- ations, maintenance, frequent calibrations, personnel training, and the expense of initial investment. The workload of a plating plant can justify the use of any instrumental technique, such as AA, ICP, chromatographic techniques, or any ded- icated electrochemical method. The following outline may be helpful in under- standing their relationship. a) Photometric methods: 1. Spectrophotometry 2. Colorimetry (measures color intensity at a given wavelength) 3. Turbidimetry (measurement of radiation passing through suspension) 4. Nephelometry (measurement of radiations scattered from suspension) All methods are based upon the absorption of light. b) Spectrophotometric methods are based on emission of light. For example: 1. Flame photometry 2. Flame spectroscopy 3. Mass spectrometry (MS) 4. X-ray fluorescence (XRF) 452 AA, ICP, spectrophotometry NA Ammonia hydroxide pH electrode AA, ICP, spectrophotometry NA pH titration AA, ICP, spectrophotometry AA, ICP NA Ammonia hydroxide pH electrode

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