| Summary: | 碩士 === 元智工學院 === 化學工程學系 === 84 === Abstract Galvanostatic
deposition of nickel-chrome-phosphorus alloys was carried outon
the rotating disk eclectrode to study the alloy composition and
the associated corrosion properties. Different rotation speeds,
bath pH values,temperatures and primary salts are used to study
the composition and efficiencyof nickel-chrome-phosphorus alloys
at the presence of additives and buffer agents. Experimental
results indicate that current efficiency decrease along
theplating time and with an increased concentration of chromium
salts. Current efficiency can be increased at the condition of
larger nickel and phosphorusion concentrations in the bath,
higher disk rotation speed, larger pH values, and higher bath
temperature. An increased disk rotation speed enhances the
deposition of chrome and phosphrous, but inhibits nickel
deposition. pH has a effect influence on nickel-chrome-
phosphorus deposition. An increased pH value raises the
deposition rates of nickel and phosphorus but decreases
thechrome deposition rate. Raising temperature of the solution
enhances nickelreduction rate but the influence on chrome and
phosphorus is not conclusive. Alloy surface morphology was
studied using SEM. Potentiodynamic method wasused to study the
corrosion properties of alloys with different compositions.
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