Introduction -
I. Mechanism of Electrodeposition -
2. Laws and Characteristics of Plating Baths -
3. The Deposit -
4. Preparatory Steps of Plating -
5. Preparation of the Surface -
6. Cleaning - 7. Pickling -
8. Strike Plating -
9. Rinsing -
10. Anodizing -
11. Brass Plating -
12. Bronze Plating -
13. Cadmium Plating -
14. Chromate Coatings -
15. Chromium Plating -
16. Acid Copper Plating -
17. Copper Cyanide Baths -
18. Iron Plating -
19. Lead Plating -
20. Lead-Tin -
21. Nickel Plating -
22. Electroless Nickel -
23. Phosphate Coatings -
24. Silver Plating -
25. Acid Tin Plating -
26. Alkaline Tin Plating -
27. Tin-Nickel -
28. Tin-Zinc -
29. Acid Zinc Baths -
30. Zinc Cyanide Baths -
31. Control of a Plating Bath -
32. Plating Tests -
33. Gravity, Conductivity, and Voltage -
34. Electroplated Alloys -
35. Layer Plating -
36. Applications of Electroplating -
37. Plating Bath Troubles -
38. Continuous Plating -
39. Plating on Plastics -
40. Preparation of Metals for Painting -
41. Analytical Methods for Plating Baths -
Appendix -
Conversion Factors -
Electrochemical Yields -
Electrochemical Formulas -
Electrochemical Equivalents -
Single Electrode Potentials -
Stripping Chart -
Glossary -
Index -
Preface -
Electroplating was born from a science that demonstrated the remarkable ability of electric current to reduce metal salts to metal.
It soon aided the production of beautiful objects and it became an art that was dependent on the masters who learned how to coax attractive coatings from homely solutions. But did the art of yesterday become the science of today? Or is the science of today the art of tomorrow? I think not. It will remain an art and a science. It is possible to design and operate an automatic plating process that is coldly technical. But it is not possible to remove personalities from the practice of electroplating.
Given a process, the individual will change it by science, logic, skill, intuition and art. Can anyone say that silver plating is best done with one strike, or two, or three. I prefer one. A friend prefers three. What is already known and communicated will help to understand but will not settle this difference. It is better to regard plating cycles as suggestions and plating baths as uncompleted formulations. The need for continuing experimentation is a vital part of every electroplating installation.
It is relatively easy to remove metal from solutions by the application of current, but only specific experimentally developed solutions produce useful electrodeposits.
If a metal salt is picked at random and current is applied to a solution of the salt, the results obtained will be varied. If the salt solution contains sodium chloride, only hydrogen will develop at the cathode.
If a solution contains lead acetate, lead will deposit, but the deposit will appear as long crystals extending into the bath. If a solution contains stannic sulfate, the stannic ions will be reduced to stannous ions at the cathode and, at least for a short time and at a low current density, neither tin nor hydrogen will deposit. If a solution contains chromic acid, only hydrogen will develop; but if a small amount of sulfuric acid is added to the electrolyte, then chromium will deposit in addition to hydrogen.
By experimentation with solutions of metal salts, baths can be developed that will produce satisfactory deposits. A great many experiments are usually required and often it is necessary to study the effect of a host of organic substances known as addition agents. By experimentation and study, new baths have been developed to fill specific needs. For example, a deposit that is satisfactory for electro refining may not be satisfactory for electroforming. A deposit that is satisfactory for electroforming may not be satisfactory for electroplating.
Electroplating is a process of electrodeposition by which a thin, smooth, sound metallic deposit is produced over a basis metal. This definition sets electroplating apart from the other processes of electrodeposition even though the requirements of the definition are not met in every case.
In this book, the fundamentals of electroplating will be briefly considered. A number of plating baths will then be discussed. It is hoped that the text will aid the practices of the science and the art of electroplating.