Surface Characteristics of Titanium Alloy by Electrical Discharge Machining

Ti-6Al-4V has many applications because of its excellent properties. However, it also has its own defects such as poor wear resistance, which limits its application. In order to improve its hardness, electrical discharge machining (EDM) method is introduced in this study. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to analyze the structural features and chemical composition. The effects of pulse on time and pulse current on the EDMed surface are analyzed. Microhardness was measured by microhardness tester. Experiment indicates that the continuous hardening layer is formed in the electrical discharge machining process. Due to the new formed TiC phase on the surface layer, the hardness of the surface layer was improved significantly. Thickness of the strengthened layer improves with the increase of pulse width.