ARMY LAB COMMAND WATERTOWN MA WATERTOWN United States
The U.S. Army Natick RD and E Center requested help from the Corrosion Science Team for their project on fabrication of a copper manikin to test insulating properties of textile materials. Sintering experiments were carried out to understand the mechanism of pore formation, the plasma spray process was explored as a means of forming the desired rough surface, and electrochemical measurements were made to assess the probability of galvanic corrosion between the copper felt and the electroformed copper in distilled water. The massive porosity formed during vacuum sintering was caused by thermal etching. Sintering in a hydrogen furnace eliminated the pore formation but caused a problem with the binder removal. A two-stage sintering process using a vacuum furnace followed by a hydrogen furnace is suggested to alleviate both problems. The difference in corrosion potential between different types of copper in distilled water is not believed to be significant and no danger of hydrogen evolution is envisioned.