Abstract
The corrosion and electrochemical behaviour of pulse plated Zn-Fe group metal alloy deposits obtained from chloride bath have been studied as a function of pulse parameters such as duty cycle, frequency and average current density. The frequencies of electric current, Ton, Toff, pulse duty cycles have large effects on the chemical composition and surface morphology of the deposits. Results of the electrochemical tests indicate that the corrosion resistance of pulse plated Zn-Fe group metal alloy coatings is superior to that of the alloy deposited by the direct current technique. The on time and off time had no significant influence on the deposit characteristics. Characterisations of deposits were carried out by cyclic voltammetry and the surface morphology was studied by scanning electron microscopy. The composition of the alloy deposits were analysed by spectrophotometry. Refinements in grain size and deposit composition have been made for better corrosion performance with the advent of pulse plating. A minimum corrosion rate was observed at 50% duty cycle and pulse frequency range of 100 Hz in all cases and is proposed as optimal conditions for development of a bright, smooth and uniform deposit of Zn-Fe group metal alloy over steel.
| Original language | English |
|---|---|
| Pages (from-to) | 208-216 |
| Number of pages | 9 |
| Journal | Transactions of the Institute of Metal Finishing |
| Volume | 87 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 01-07-2009 |
| Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys