Abstract
Factors affecting the machining properties of pure titanium with both ram and wire-type electric discharge machining were investigated. Surface texture and mechanical properties of the titanium specimen made by the electric discharge machine were also examined. The polarity of electrode and the electric conditions were found to affect the machining properties. For the electric discharge machine investigated in this study the conditions of pulse magnitude 16 A, pulse on time 100 μsec., pulse off time 60 μsec., and reversed polarity were found to be efficient in practice. The material of the electrode was also found to affect the machining properties. The copper electrode showed more sufficient machining properties than the other materials. Pure titanium was found to be machined easily by the wire-type electric discharge machine with the same electric conditions as stainless steel, and showed excellent machining properties. The electric discharge machining showed a matte finish with many small spots, and the wire-type electric discharge machining had smaller spots than the ram-type electric discharge machining. A hardening layer was found in the surface of the specimen made by the ram-type electric discharge machine and the thickness of the hardening layer was affected by the current conditions. No hardening layer was found in the surface of the specimen made by the wire-type electric discharge machine. The specimen made by the electric discharge machine showed sufficient tensile strength and elongation.
