After machining an alloy using WEDM or any other non traditional machining processes, what kind of analysis can be performed for testing surface and sub surface conditions?
It all depends on what properties you want to investigate. If you can perform destructive tests , I strongly recommend scanning electron microscope analyses both on the surface of your material and on a cross section of it, making use of X-ray EDS microanalysis. In this way you can check microstructural surface and in-depth features, both morphologically and chemically. X-ray diffraction can help you if you want to perform phase analysis of the surface. In this case make sure the surface be flat. If destructive tests are not allowed, as non-destructive ones I would suggest profilometry for information about surface roughness, and X-ray or ultra sound techniques for detection of possible in-depth defects or inhomogenieites.