Manufacturing OF-OK
OF-OK manufacturing starts with high-quality copper cathodes melted under strictly controlled conditions and cast in an inert atmosphere into cakes. During this process the copper is not allowed to come into contact with air. Intermediate or final annealing is done either in a reducing atmosphere or a vacuum.
Properties
The most important properties of Luvata OF-OK copper are its purity and freedom from oxygen. It also has high electrical and thermal conductivity, toughness, good working qualities and high surface quality.
The purity of OF-OK (Cu min 99.99%) gives it high electrical conductivity, but its main advantages are its immunity to hydrogen embrittlement and the fact that it can be flow formed better than any other copper grade. High purity and homogeneity ensure the consistency of its material properties. Consistency from the first to the last piece, and from batch to batch, reduce setting time and machine down time.
Applications
OF-OK copper is the ideal material for:
- Electrical and electronic applications
- Printed circuit boards
- Heat sinks for semiconductor bases
Welding and Brazing
Hydrogen embrittlement occurs when hydrogen ions diffuse into copper at high temperatures, and form water with the oxygen atoms they find there. This water vapour has a high enough pressure to make pores in the copper.
Hydrogen embrittlement can also occur when copper components are brazed or welded in a reducing atmosphere containing hydrogen. In commercial copper grades, which usually contain 200 to 600 ppm (0.02 - 0.06%) of oxygen, the result is a completely brittle metal. In OF-OK we guarantee the oxygen content will be a maximum of 10 ppm (0.001%). The lack of oxygen and the low impurity content mean that OF-OK copper is well-suited to all types of welding and brazing.
Silver Bearing Copper OF-OK (Ag)
Alloying copper with silver significantly improves e.g. its softening resistance properties. Even a small amount of silver enhances the softening temperature of Luvata OF-OK without sacrificing its high conductivity and formability. Typical applications for silver bearing copper are commutators for small motors and graphic plates for the engraving industry.