Black oxide gives copper shielding material better adhesion and performance properties

Copper sheets before and after
black oxiding

Cleveland, OH –Watteredge Inc. of Avon Lake, OH is a leading producer of cables, switches and connectors for the power, battery and welding industries. They recently received a contract to produce copper shielding material for use in medical diagnostic equipment.

These copper sheets are bonded together with other materials that make up the shield assembly. Because the shield is subjected to repeated heating and cooling, uneven adhesion of the copper sheets with other layers could degrade performance of the equipment. To enhance bonding with other layers, the surface of the copper needs to be prepared properly.

Initially, Watteredge abraided the surface of each copper sheet by hand to achieve the correct adhesion qualities. This procedure produced inconsistent results and was very labor intensive. Each sheet is approximately 122” x 30”.  There was also a problem of surface corrosion that formed over time on the copper plate after abrasion. A better method was needed, so the company contacted Cleveland Black Oxide in the hope that a black oxide finish might solve some of these problems.

Cleveland Black Oxide is experienced with black oxide finishes for copper, stainless steel and other non-ferrous and ferrous metals. They also happened to have tanks big enough to handle the large sheets. Testing at Cleveland Black Oxide confirmed that their black oxide finish would offer the surface adhesion characteristics Watteredge was looking for.

Black oxiding the copper sheets has also eliminated the necessity of hand roughing the surfaces and produces a more consistent finish from sheet to sheet and batch to batch.  The sheets are only .010” thick and black oxide, because it is a surface conversion process and not a coating, does not alter the dimensions of the parts.

Cleveland Black Oxide is the largest commercial black oxide finisher in the U.S. and processes over 8-million pounds of carbon, alloy, stainless steels, brass, bronze, copper, die cast zinc and cast iron each year.  It has the largest black oxide tanks in the business – 17-ft for steel and 12-ft for stainless steel.

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