MICROSTRUCTURE ANALYSIS AND MATERIAL TRANSFORMATION OF PURE TITANIUM AND TOOL WEAR SURFACE AFTER WIRE ELECTRIC DISCHARGE MACHINING PROCESS

Abstract

The wire electric discharge machining process is an alternative for machining of the high strength temperature resistant materials. The present research work is mainly focused on the investigation of integrity of the work surface and wire electrode surface after machining with WEDM. Experimental results showed that pulse-on time, pulse-off time and peak current significantly affected the surface integrity with the formation of deep-wide overlapping craters, pock marks, debris, micro-cracks and recast layer. Both carbides and oxides were formed either in free form and/or in compound form due to decomposition of de-ionized water, machined samples and wire material. The compounds like titanium dioxide (rutile) (TiO₂), (TiO_0.325), Ti₂O₃ , Ilmenite (Fe₂Ti₄O), titanium carbides (TiC) and copper titanium dioxide (Cu₃TiO₄) were formed due to phase transformations that were analyzed through X-ray diffraction and energy dispersive X-ray method. The effect of process parameters on the wear of wire surface has also been considered.

Keywords:

• craters
• EDX
• heat affected zone
• micro-cracks
• microstructure
• recast layer
• surface topography
• titanium
• WEDM
• XRD

ACKNOWLEDGMENTS

The authors highly acknowledge to General Manager, Central tool room (CTR), Ludhiana, Punjab, India, for providing the necessary wire electric discharge machine setup for experimentation. The authors are also thankful to Prof. Harpreet Singh and Ms. Narinder Kaur (Lab Superintendent), IIT, Ropar for providing laboratory facilities (SEM, XRD, and EDX).

Notes

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