摘要 |
An EDM wire having an outer coating of gamma phase brass with an overlayer of continuous unalloyed zinc or ductile epsilon phase brass entrapping the gamma phase and a process for manufacturing the EDM wire is provided. A second process for synthesizing a ductile epsilon phase brass coating on the aforementioned and other substrates is also provided. The first process includes coating a copper bearing metallic core with zinc. The zinc coating is then converted to gamma phase brass via a diffusion anneal and subsequently re-coated with zinc prior to being cold drawn to its finish diameter. The process of converting a zinc coating to a ductile epsilon phase brass includes heat treating the wire at a temperature low enough to minimize or eliminate changes in the mechanical properties of the composite wire. |