EDM induces structural sub-surface changes to a depth of several micrometers. If you are interested in the structure of the bulk material, you should eliminate (e.g., by electro-polishing) a layer og the original surface left by EDM (besides the necessary cleaning, of course). The case is much more important if you want to observe your sample by TEm.
Thank you Dr. Sevillano for the response. My requirement is just to remove the carbon particles deposited on the specimen surface to carryout machined surface characteristics. For such a purpose, is there any option other than ultrasonic cleaning?
For surface topography analysis no need of polishing. if you need to analyse subsurface cut it cross sectional and do etching further it can be analysed recast layer thickness and microhardness etc.
But Mr. Galpuji, I dont think etching is a good option as it may slightly change the surface texture after machining what ever the strength of the media we use. And it is hazardous.
And taking cross sectional sections also have their limitations. If we employ techniques like Wire EDM for sectioning, problem of recast layer formation at the cut zone may happen. Applying mechanical means to take cross sectional cuts is not feasible for materials like Titanium.
Instead of doing cross sectional cutting of the machined specimen, we may use a split specimen.
you are measuring alterations affected by EDM or WEDM why you are going for again. you need used diamond saw cutting with very low speed that will not affect the surface properties. I suggested etch cross section surface not machined surface.
Since you measuring alterations affected by EDM, You can wash the machined surface of the alloy with acetone using ultrasonic cleaner to prepare it for topographic features examination. We ve tried this possibility on the alloy (Ti-6Al-4V). As for the analysis of the recast layer, the cross section of the specimens can be grounded with emery papers with the range of 240 to 1000 grits and then polished.