Abstract
This research presents a novel process using micro electro-discharge machining (micro-EDM) combined with high-frequency dither grinding (HFDG) to improve the surface roughness of micro-holes. Micro-EDM is a well-established machining option for manufacturing geometrically complex small parts (diameter under 100 μm) of hard or super-tough materials. However, micro-EDM causes the recast layer formed on the machined surface to become covered with discharge craters and micro-cracks, resulting in poor surface quality. This affects the diameter of the micro-hole machined and undermines seriously the precision of the geometric shape. The proposed method that combines micro-EDM process with HFDG is applied to machining high-nickel alloy. As observed in SEM photographs and surface roughness measurement, HFDG method can reduce surface roughness from 2.12 to 0.85 μm Rmax with micro-cracks eliminated. Our results demonstrated that micro-holes fabricated by micro-EDM at peak current 500 mA followed by HFDG at 40 V can achieve precise shape and good surface quality after 6-8 min of lapping.
Original language | English |
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Pages (from-to) | 80-87 |
Number of pages | 8 |
Journal | International Journal of Machine Tools and Manufacture |
Volume | 46 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2006 |
Keywords
- HFDG
- High-nickel alloy
- Micro hole
- Micro-EDM
- WEDG