Wire electric discharge machining (Wire-EDM) induced a new phase in Ti-46Al-2Cr (in at.%) intermetallic alloy has been identified by using X-ray diffraction technique. The new phase is found to be neither TiO2 nor Al2O3, but well consistent with fcc structure titanium hydride with the lattice parameter of 4.49-4.50 Å. The new phase exists in the wire-EDM cut alloy surface layer limiting to about 70 μm thick, much deeper than the wire-EDM induced recast layer thickness of 2-3 μm. One processing, vacuum annealing at 400-600 °C, has been proposed to remove this hydride induced by wire-EDM. In addition, The wire-EDM induced microcracks extensively happen on the EDM-cut surface and penetrate into matrix up to 10-30 μm.
- A. Titanium aluminides, based on TiAl
- C. Electric discharge machining
- F. X-ray diffraction