Electric discharge coating on graphite using W–Cu sintered tool

ABSTRACT

This article describes about the modification of graphite surface by depositing a hard layer of tungsten (W) and copper (Cu) material using electrical discharge machining (EDM) setup in reverse polarity. The sintered tool is prepared by heating a Powder Metallurgical (P/M) green compact of 75%W-25%Cu at 900 ⁰C in an argon atmosphere. The deposited layer is studied by evaluating the Tool Wear Rate (TWR), Material Deposition Rate (MDR), and Surface Roughness (Ra). The coating is characterized by FESEM, EDS, and XRD analyses. The existence of tool particles (W and Cu) and carbides of tungsten (WC and W₂C) are witnessed on the graphite surface. The tool materials are impinged up to 19.93 µm of depth from the surface level. The experimental results show an increase in thickness of the coating with increased peak current settings. Minimum thickness of 15.46 µm and maximum thickness of 33.93 µm are found in the experimentation.

KEYWORDS:

• EDM
• sintering
• graphite
• deposition
• coating
• FESEM
• EDS
• XRD

Acknowledgements

The authors would like to express their thanks of gratitude to SERB-DST New Delhi, India for funding this research work. The authors are also thankful to CSIR-NEIST Jorhat for providing the facilities of FESEM and EDS analyses. The authors are grateful to CIF-NIT Silchar for XRD facilities.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The funding support is obtained from Science and Engineering Research Board-Department of Science & Technology SERB -DST New Delhi India [Sanction Order No. ECR/2017/000795].