| 配方类型： |
METALS AND THEIR TREATMENT |
| 配方说明： |
Palladium-Plating Baths |
| 配制方法： |
As a precious metal, palladium is tarnish resistant and also is more than nickel or chromium to most acids except nitric acid. In color it closely resembles nickel and its hardness equals or surpasses a nickel deposit from a Watts solution. Real progress was made in palladium plating with the introduction of the amino compounds and alkali double nitrites of palladium.
A typical bath consists of 8 g. per liter palladium aminonitrite dissolved in a small quantity of ammonia, 100 g. per liter ammonium nitrate, and 10 g. per liter sodium nitrite. If this solution is operated with a pH above 7, by the addition of ammonia, the deposits obtained become smoky rather quickly, but heavier deposits can be built up by means of intermittent scratch brushing. In all cases, it is necessary to keep the voltage below the gassing point. If the pH is below 7, the deposits have a tendency to be brighter, but at the same time the danger of peeling increases.
Palladium - plating solutions made up with the alkali double n |
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