MES Takes On a New Challenge: Oxygen Free Copper

At MES Inc. we love to take on new challenges and no challenge is too big for us. When one of our oldest clients presented us with a request for oxygen free copper to be used in vacuum interrupters, the sourcing team took on the almost impossible task of finding a supplier for the highly restrictive material. Impossible because there are only a handful of suppliers in the world.

All high conductivity coppers contain some oxygen as a result of the copper refining process, but certain applications require copper with the highest purity and lowest oxygen levels. This project required the higher purity Cu-OFE (oxygen-free electronic) with 99.99% copper with silver removed and oxygen removed to 0.0010%. No copper is 100% pure but Oxygen Free High Conductivity Copper (OFHC) has only a trace of oxygen. In practice the oxygen content is typically 0.001 to 0.003% with a total maximum impurity level of 0.03%. The purity of OFHC makes it suitable for conductivity applications in vacuum conditions. OFHC is used for magnetrons, klystrons, vacuum seals, tubes, capacitators and interrupters, waveguides and microwave tubes.

In a couple of weeks, the sourcing team, in collaboration with the quality team, was able to locate a supplier in India that was willing to take on the challenge of developing the capability to manufacture OFHC in the form of rods of varying diameters, to be then forged and machined for the final parts.

They worked with this converter to develop the capability to produce the OFHC Copper with a maximum of 0.0010% Oxygen through a specific converting process to take from ingot to finished OFHC copper rods of varying diameters.  This flexibility of sizing was very critical capability providing a major competitive advantage of being able to Cold Forge to near-net-shape, which eliminated significant amounts of wasted high-value material and machining time.  Moreover, localizing the sourcing of this high-value material eliminated the costs and challenges associated with importing material from sources thousands of miles away.

MES realized a significant cost reduction for our client:

• Up to 40% in material cost related to the variety of rod diameters to suit the near-net forgings;
• Cost savings associated with sourcing and opening up a tight field of approved converters; and
• The cost associated with reducing material lead-times from 10 weeks to 3 to 4 weeks.