Experimental Investigation and Optimization of EDM process in different Paramaters on NICKEL material (nimonic 8A)

. Newly prepared Nickel alloy (Nimonic80A As Per ASTM B637 Alloy-N07080) using powder metallurgy is considered in this investigation. In Conventional machining, Nickel alloys produce higher tool wear rate , poor surface Finish, but this can be reduced by Electrical Discharge Machining (EDM) method. Nickel alloy(Nimonic80Aas per ASTM B637 Alloy-N07080) presently used in wide variety of applications such as Automobiles, Aerospace industries, because of their high strength to temperature ratio. In this project, Nickel alloy (Nimonic80A as per ASTM B637 Alloy-N07080) is taken with different types of EDM Properties. Before that Chemical characteristics in addition machinelike possessions as well as to a degree Tensile test,Charpy test are administered on for judgment substance moreover severity of the material plus from that timeforward we acted EDM process by utilizing of TAGUCHI procedure. Results of tests are resolved to select high quality surface finish moreover fastest process for material request.


EDM discharge principle description
When electrode as well as work piece gradually approach, the strength of electric field between poles gradually increases, electrical ionizing particles in working liquid begin to gather toward electric field, while negative charged electrons also break through insulation , inject from cathode surface, accelerate to anode, a strong electric field is formed in between.*Corresponding author: sateeshnagari1@gmail.com * , 01 (2023) E3S Web of Conferences ICMPC 2023 https://doi.org/10.1051/e3sconf/202343001239239 430 1.1.2Relationship between processing speed, current as well as pulse width Processing speed is proportional to amount of current, when pulse width remains constant, the greater the current the faster the processing speed, but when the current value exceeds 10A/Cm, processing speed has a tendency to decrease, therefore fine pores as well as small area should apply smaller current to process.When the pulse width is extremely short more over very long, even if the charging then discharging have the same ratio, processing speed also tends to be slow.When pulse width is very short, peak current has not yet reach rated current is a major reason.When pulse width is long, current density decreases, voltage drops as well as not easy to remove molten metal, amount of metal residues increase, machining surface becomes roughness deterioration, work piece turns to be glossy surface; such processing makes surface metamorphic layer thicker, poor efficiency more over it is not practical.It is necessary to aware appropriate match of current size then pulse width.

Low electrode consumption processing principle
Many factors affect electrode consumption, there are two main points: Apply original material characteristics, that is, the value of multiplication e thermal conductivity along with melting point, the larger the multiplication the lower of consumption of consumption.Processed carbon generated by processing can protect the attachment of anode, which lowers electrode consumption.

Application of EDM
The difference of EDM along with conventional machining method is to apply heat for processing, therefore regardless hardness, toughness, as long as work piece is conductive material, all can be processed, in particular, the hardened steel, tungsten carbide in addition to other super hard metal.Machining stress generated by EMD is extremely small, negligible, what's more processing surface has no comatulid, it is suitable for thin slices further moresmall holes.No rotation needed in processing; therefore it is more favorable for complex and irregular shape processing .In recent years technological advances, constantly improved by professionals; for general steel processing, electrode consumption is lower than 0.2%, surface Accuracy is up to 0.3μmRa, so the technology is applied in high-precision mold moreover AW aviation equipment processing.

Slagging description
Slagging is to have working liquid cycle between electrode with work piece correctly, an important factor to EDM, suitable slagging can achieve the best processing effect.Let us analyze the changes in gap without slag processing.In the beginning, working liquid is clean, the insulation of clean working fluid is better than the working fluid containing particles; there is delay time before insulation breakdown too then produce the first discharge.After the first discharge particles are produced, also the residue generated in gap gradually increases, thus gradually reduces the insulation strength of working liquid insulation, so discharge can be easier.

EDM terminology
A machined surface roughness e roughness of EDM surface, side roughness with bottom roughness are afferent; at the same current in addition to same discharge frequency, side surface roughness The surface is finer than bottom surface roughness, as will as the larger the current or less consumed discharge frequency, the rougher the processed surface, the unit Microns Ra.

Discharge gap (GAP)
Discharge gap stands for after processing the enlarged electrode size; general speaking, the greater the current or the lower the discharge frequency (low electrode consumption) or local power supply voltage is too high, working fluid is too old or dirty, all introduce larger discharge gap.Together with processing deep mold , discharge duration is long will generate secondary discharge are easy to enlarge discharge gap.

Processing speed
The amount of processing unit generally is presented in weight, such as number of grams per minute (g/min),volume, how many cubic centimeters per minute(mm³/min) Electrode consumption ratio The percentage ratio of electrode consumption (AE) , work piece processing amount (AW), generally is presented by weight ratio, length consumption ratio with volume consumption ratio.Such as AE/AW x 100=%.

Literature review
Li Liqing, Wang Yunhang [1] developed Studying to its environmental friendliness, electrical discharge machining in gas (dry EDM) is a reliable substitute technique for traditional liquid dielectric EDM.Ma Liangqi [2] proposed a method In order to guarantee the machining precision of the micro-hole array, this study investigates the flow velocity simulation analysis of the working fluid, which is essential in the flushing of discharge debris, the experimental study on the axial wear of tool electrode.Giancarlo Maccarini [3] developed In this paper, the machining time , electrode wear rate (TWR) of nickel-based alloy , titanium alloy machined by EDM were studied by orthogonal experiments.Daisuke Yanagida [4] proposed a method of In this paper, the effects of the work piece, electrode material too dielectric fluid in micro-EDM drilling process were investigated and a check for potential interactions was performed.Jianguo Lei [5] developed In the present study, different materials disc foils including Cu, Cu-Sn alloy and Sn disc foils were used to construct a laminated disc electrode (LDE) blank, performing EDM to fabricate LDE with stable micro channels on the outer edge surface, and then the LDE was applied in EDM to produce microgrooves on work pieces with the same machining conditions.Wei Liang [6] proposed in this paper This research focuses on verifying the feasibility of break-out detection using audio signal in drilling film cooling holes by EDM with inner and outer flush.The electrical discharge machining (EDM) process with inner and outer flush is effective for drilling film cooling holes on the blades of aero engines and gas turbines.Tzu-Wei Huang[7] developed A new process of micro-EDM for high precision micro ball-tip stylus fabrication by commercial pipe electrode tool was proposed in this study.In order to fabricate smaller micro ball-ended tip stylus, a high precision hollow pipe electrode tool with inner diameter 0 .05mm was made by micro-EDM drilling in this study.ShunFei Shi, Fei Yang [8] developed The experimental verification shows that the proposed electrical model can predict the gap conditions in real machining, and assist the discharge current and discharge energy control.Hidenori Inada [9] developed a Small diameter-deep hole drilling is indispensable when several main parts of which airplane, automobile, machine tool and metal mould are manufactured.Especially, medical appliances, medical implants and surgical operation tools for brain and bone invariably need small diameter-deep hole drilling for hard-to-machine metals such as stainless steel and Ti6Al4V.Huan Liu, Jicheng Bai [10] developed The AM-Cu electrode, whose thermal conductivity has been improved by heat treat after additive manufacturing, exhibits the same EDM properties as the conventional Cu electrode and can be applied as an EDM tool electrode.Vinoth Kumar [11] proposed a method of Electrical discharge machining in gas (dry EDM) is a promising alternative technology for conventional liquid dielectric EDM because of its environmental friendliness and low tool relative wear.Ma Liangqi, Wang Xiaoying [12] proposed a method of Al6061-TiC composite with 4 wt% TiC was produced by the reaction of halide salt K2TiF6 and C with the molten aluminum.Amrish Raj.D [13] wrote in this paper The demand for higher efficiency in aircraft propulsion engines leads to materials with increasing thermo mechanical strengths.The inter metallic gamma titanium aluminizes (g-TiAl) are attributed a great potential in this field, but the machinability of g-TiAl by conventional processes is challenging.Manisha Priyadarshini [14] proposed a method of Electric discharge machining (EDM) is commonly used to machine precise and tiny parts when conventional cutting methods face eifficulty in meeting productivity and to clearance requirements.Especially, EDM-drilling is an efficient process for the fabrication of micro-diameter deep hole even though material type is difficult to cut such as high strength steel, cemented carbide, and titanium alloys.C. Mascaraque-Ramirez [15] proposed a method of Implementation of die-sinking EDM for precision machining of meson-micro-scale features with surface area smaller than 10 mm2 down to 0.1 mm2 is mainly restricted by electrode machining and electrode wear.Doctor Fleming [16] proposed a method In order to describe the thermo-physical phenomena involved in this process more over estimate the expected results for different cutting conditions, not only the experimental observation but also the numerical modeling is convenient.U. Maradia [17] proposed a method of Electrodischarge machining (EDM) is a non-conventional cutting technology widely applied to generate mechanical parts with a complex geometry.Cheol-Soo Lee [18] proposed a method of Die-sinking electric discharge machining (EDM) is one of the essential non-contact machining processes which is often used to produce complex profiles.However, machining of titanium alloys is found to be difficult even using EDM due to the inadequate process parameter sets affected by improper parametric correlation.

Material Introduction
Nimonic 80A alloy is a nickel-chromium alloy that is strengthened by the additions of titanium as well as aluminum.It has high tensile as well as creep-rupture properties at temperatures up to 815°C (1500°F).The following datasheet will providean overview of nimonic 80A alloy.

Chemical Composition
The chemical composition of nimonic 80A alloy is outlined in Table 1.

Experimental work
The machining criteria used for this work is EDM machine , copper electrode inclusing nimonic 80A material formachining by different types of operations ,parameters to use of Taguchi method get results.3.In this below experiment Taguchi method used of one internal current 13 amps , different types of Ton, Tau s.Various types of results shown in Table 4.In this below experiment Taguchi method used of one internal current 15 amps , different types of Ton,Tau s.Various types of results shown in Table 5 The process machining criteria used for this work is intended to obtain required machine, requirements used in CITD Hyderabad.The operation results to find the further as well as best finishing, depth of cut, MRR optimized by above results.In this operation the Taguchi method is used too in every eight experiments different types of parameters are used to get the best results.Here MRR, surface finish found in constant time.The following tests have been performed Central institute of Tool Design, Hyderabad laboratories.

Results and Discussions
Electrode as a copper and work material Nickel(Nimonic 80A).Then It is used to take different types of conditions , parameters then I got the below results.The main objective of the present work, 'depth of cutting, speed of work, surface finish' is achieved as per the author's expectations.An extensive study has been done on the test coupon, which can reflect identical characteristics of the actual Nimonic 80A material cutting process by using EDM machining.Further EDM machining using the Copper electrode , nimonic 80A material as a workpiece, along with the input power that is IP, TON amplitude , TOFF amplitude then the cutting performance has been observed.The input power is 8 Amps to 15 Amps used as well as Ton 30 µ, 75 µ,100 µ, and Tau as 12 µ,24 µ,34 µ the time duration used for all experiments is constant time 15 minutes.like used here The cutting spark growth rate in linear direction is in 8 Amps,100 µ Ton, Tau 32 µ in this the highest depth is 3.835mm.and as same in surface finish 8 Amps,30 µ Ton, Tau 12 µ has got best surface finish 1.3 microns.Overall in this experiment highest surface found at 0.8microns for input power is 13 Amps, Ton 30 µ, Tau 24 µ in this the depth was also found 2.79mm depth.as well as the overall depth of this experiment in 6.09mm in the parameters of input power 15Amps, Ton 100 µ, Tau 32 as used.Additional experiments involving twin this EDM approaches are called for.Surface finish as well as MRR also found, on EDM machining performance will be the subject of future research.

Conclusion
As experiment found best parameters of EDM operations made on Nickel alloy Nimonic 80A as well as copper electrode were used all the parameters were observed to be in-plane tensile in nature.The S/N ratio analysis was conducted , an optimal parameter setting was obtained at level 1 for TON, level 1 for IP , level 2 for TAU where low or negligible residual stresses were observed.Analysis of variance was con-ducted at a confidence level of 95% as well as it was found that all the main control factors TON, IP , TAU had shown significant effect.Among the interactions one 2-way interaction (TON*IP) , 3-way interaction (TON*IP*TAU) had shown significant effect, whereas the rest of the interactions TON*TAU, IP*TAU had shown no effect on residual stresses.Increased residual stress and surface roughness values were observed with an increase in cutting speed.The spark energies generated during machining at various conditions led to the formation of various intermetallic phases viz., Nimonic 80A.The Nimonic 80A inter metallic observed in case-1 condition was much more anisotropic than other inter-metallic, so its formation must be either prevented or con-trolled.The various IP value obtained in this investigation was 8amps to 15 amps also TAU 12, 24 32amps were used and TON 50, 75, 100 amps were used in each experiment.hence, no surface cracks were observed at any of the machining conditions.Though surface cracks were not observed, higher values of residual stresses furthermore surface roughness were not preferred for long service life as well as for good surface integrity.

Table 2
shows the physical properties of nimonic 80A alloy.