Surface characteristics of Ti-6Al-4V by SiC abrasive-mixed EDM with magnetic stirring

Ti-6Al-4V is widely used in aerospace, biomedical applications and in many corrosive environments. However, titanium alloy has low hardness and poor wear resistance. This paper introduces a machining method of SiC abrasive-mixed electrical discharge machining (EDM) with magnetic stirring. Structural features and chemical composition were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). Micro-hardness distribution on the cross section was measured with an FM800 micro-hardness tester. The influence of pulse width and pulse peak current on the formation of the surface hardening layer is analyzed. The results show that a continuous strengthened layer was formed during the SiC abrasive-mixed EDM process. The hardness of the formed layer was significantly improved because of the formation of TiC and TiSi₂ phases on the machined surface. With the increase of pulse width, the thickness of the strengthened layer increases and the quality becomes better.