Abstract:
Inconel-625 is a nickel-alloy based material with properties such as high hardness, oxidation
resistance, and high fatigue strength. These properties make it suitable for
applications in power generation, marine, and aerospace industries.
Due to high hardness of the material, it is di cult to machine it by conventional machining
methods such as turning, milling or grinding. For this reason, Wire Electrical
Discharge Machining (Wire EDM) is adopted as an alternative method to machine the
material. The competences of this machine includes the fact that it is able to make
straights cuts for surface roughness measurement, as opoposed to Sinker EDM which
is speci ed in making internal cuts. Once selecting wrong control parameter-levels, the
method is accompanied with challenges such as wire breakages, short circuiting of wire,
poor surface nish and low material removal rate, leading to high production cost.
In this research, experimental investigations were done to know the in
uence of pulseon
time (ton), wire feed rate (fw) and gap voltage (vg) on surface roughness (SR) and
material removal rate (MRR). An Algorithm was developed from mathematical model,
developed using Response Surface Methodology (RSM), to correlate input control parameters
with output performance measures. The machining process was optimized
using Taguchi optimization technique. Inconel-625 plates of 10 mm thickness were used
as specimen in experimental work.
It was found out that, for machining of Inconel-625 using wire electrical discharge machining,
brass wire as cutting wire, and de-ionized water as medium
uid, the minimum
surface roughness can be achieved for pulse-on time, wire feed rate, and gap voltage
of 0.4 s, 8 mm/min, and 68 V, respectively, whereas for maximum material removal
rate, the pulse-on time, wire feed rate and gap voltage should be 0.6 s, 10 mm/min,
and 56 V, respectively. For improved material removal rate and surface roughness, it
was observed that the pulse-on time, wire feed rate, and gap voltage could be 0.5 s,
8 mm/min, and 62 V, respectively. The optimization improved surface roughness and
material removal rate by 5.68 % and 3.041 %, respectively.
It is recommended that other output performance measures such as kerf width, corner
accuracy and dielectric
uid
ow rate may be considered for further investigations.
