Sodick’s high-speed EDM machining of multi-cavities inTitanium
SodicoM's Exclusive Know-How
EDM process with multi-cavity and multi-electrode
Super-Low Electrodes Wear
Die-Sinking High-Precision Electrical Discharge Machine Sodick Sodick AG40L LN2 (special titanium technologies and techniques developed by SodicoM engineers)
Machined in 13 different positions with one multi-electrode of 52 pins — in total 676 cavities with one set of electrode.
Workpiece: titan t=4,1 mm (aerospace intake part)
Electrode: copper (52 copper pins)
Total machining time of 52 cavities:
3 h 00 min — 3 h 10 min
Total machining time of 676 cavities (13 positions):
≤ 40 hours (with one set of electrode)
Vector angle depth: 6.1 mm with 31º
One electrode size: 4,1 × 3,9 mm
Electrode wear (end): 0,14 мм
Technology
Each position was machined in 4 modes:
– running in
– rough EDMing
– finishing 1
– finishing 2
In the process, we simulated the machining with two electrodes (rough and finishing). As a finishing electrode was used a higher unused in roughing portion of the same electrode.
The final finishing depth was selected based on the value of the end wear of the rough electrode plus the double thickness of the machined plate:
N·W+2H=Z finishing
where:
N – number of planned positions
W – electrode wear after rough EDMing of one position
H – workpiece plate thickness
The workpiece housed 13 machining positions. Knowing that W (end wear) = 0.14 mm, H = 4 mm, we get Z finish depth = 9.82 mm.
Explanations
The strategy when first only rough EDMing is done and then all finishing cuts has the advantage that at the beginning of each new rough machining the electrode has an isomorphic shape of the end part, which ensures the same rough EDMing time.
Using the strategy “two in one” (roughing and finishing in one pass) leads to an increase in processing time due to increasing distortion along the height of the electrode, which requires deeper processing of the subsequent position.
Conclusion
The proven technology of titanium plate EDMing allows increasing the use of the same electrode several times.
Technology Developer::
Igor Sychev, vice chief engineer, chief specialist of R&D of SodicoM
Sergei Godin, EDM application engineer