In this study, the electrical discharge machining (EDM) of titanium alloy (Ti–6Al–4V) with different electrode materials namely, graphite, copper and aluminium and process parameters such as, pulse current and pulse duration were performed to explore the influence of EDM parameters on various aspects of the surface integrity of Ti6Al4V.

1. Electric Discharge
Machining of Titanium Alloy
SAHIL DEV
10406EN016
MECHANICAL, IIT-BHU

2. Contents
 Introduction
 Electrical Discharge Machining
 Why to use EDM
 Metal Removal Mechanism
 Experimental Procedure
 Experimental Result
 Conclusions
 References

3. INTRODUCTION
 Titanium alloys are widely used in many industrial and commercial
applications. Examples: aerospace, chemical, automotive, medical
and sporting goods
 Ti-6Al-4V is the most common Titanium alloy
 Difficult to machine with the use of traditional machining process.
 High manufacturing cost
 Poor surface finish
 Electrical discharge machining is very efficient to machine such
alloy

4. What is EDM
 Electrical Discharge Machining,
also known as Spark Machining,
Spark Erosion.
 Used on hard metals.
 Works with electrically
conductive materials.
Source: Ref. 1

5. PERFORMANCE MEASUREMENT
 Material Removal Rate
 Tool Wear Rate
 Surface Quality

6. PROCESS PARAMETERS
 Spark On-time
 Spark Off-time
 Discharge current
 Electrode material

7. EXPERIMENTAL PROCEDURE:
Ti-6Al-4V ALLOY
 Alpha + Beta alloy
 Heat treatable
 High strength
 Low weight
 High corrosion resistance
 Used in aerospace industry

8. EXPERIMENTAL PROCEDURE

9. WORKPIECE MATERIAL PROPERTIES
Source: Ref. 1

10. ELECTRODE MATERIAL PROPERTIES

11. MACHINING CONDITION
Source: Ref. 1

12. EXPERIMENTAL RESULT: SURFACE
ROUGHNESS
 Surface roughness increases with
increase in pulse current or pulse
duration.
 Surface roughness improved at
extended pulse duration, i.e. 200µs
 Aluminium electrode produces best
surface finish while graphite shows the
poorest.
Source: Ref. 1

13. WHITE LAYER THICKNESS
 Exists due to the solidification
of the molten metal which is
not flashed away by the
dielectric
 White appearance observing
through the optical
microscope
 Affects the hardness of
material
Source: Ref. 1

14. WHITE LAYER THICKNESS
 Increases with the increase
in pulse current or duration
 Thicker for graphite
compare to the copper and
aluminium
Source: Ref. 1

15. MATERIAL REMOVAL RATE
 Increases with the increase in
pulse current and pulse
duration.
 But for extended pulse
duration i.e. 200µs MRR
decreases.
 MRR is highest for the graphite
Source: Ref. 1

16. TOOL WEAR RATE
 Increases with the increase in
pulse current and pulse
duration.
 For aluminium tool wear rate is
the highest and MRR is the
lowest.
Source: Ref. 1

17. CONCLUSIONS
 The material removal rate, surface roughness and electrode wear
are increasing with process parameters for each electrode material
except the prolonged pulse duration of 200µs.
 The average white layer thickness is increasing with EDM parameters

18. REFERENCES
 Ahmet Hascalık and Ulas Caydas, “Electrical discharge machining of titanium
alloy (Ti–6Al–4V)” Applied Surface Science 253 (2007)
 Mohammadreza Shabgard and Mirsadegh Seyedzavvar “Influence of Input
Parameters on the Characteristics of the EDM Process” Strojniški vestnik - Journal
of Mechanical Engineering 57(2011)
 Serope Kalpakjian and Steven R Schmid, Manufacturing Engineering and
Technology, Prentice Hall; 6th edition (27 Mar. 2009) Chapter 26: Advance
Machining Process, Page no. 774.
 www.sciencedirect.com/science/article/pii/S0169433207006988
 http://en.wikipedia.org/wiki/Electrical_discharge_machining

19. THANK YOU