Studies on the surface of high-performance alloys machined by micro-EDM

ABSTRACT

Micro-electrical discharge machining (EDM) is used in the fabrication of Ti-6Al-4V, SUS304, and SKH59 alloys, which are important aviation materials. EDM influences the surface morphologies of these materials and directly affects their reliability during use. However, current research focusing on the morphology of surfaces machined by micro-EDM is rare. Traditional surface evaluation parameter such as R_a cannot describe the surface morphology machined by micro-EDM precisely. Therefore, systematic research on surface morphology of the aforementioned alloys is presented in the study. Based on a novel evaluation method combining fractal theory with wavelet filters, first, comparative experiments on surface morphology evaluations of different materials were conducted and discussed. Second, two different pulse power supplies were studied to explore the effect of pulse power on the high-performance alloy surface. Third, three different micro-EDM processing methods were compared to study their effects on the surfaces of high-performance alloys. Finally, different machining parameters such as discharging energies, rotation speeds of the tool electrode, and gap voltages were set to investigate their effects on the surface morphology. The results showed that different materials, pulse power supplies, processing methods, and machining parameters greatly influence the surface morphology quality, and appropriate machining advice is proposed.

KEYWORDS:

• Discharge
• electrode
• filter
• fractal
• machining
• morphology
• surface
• wavelet

Additional information

Funding

This work was supported by the National Nature Science Foundation of China for Young Scientists under Grant No. 51505400; the Fundamental Research Funds for the Central Universities of China under Grant No. 20720160085.