Parameter optimization and experimental study on wire electrical discharge machining of porous Ni40Ti60 alloy

Author(s):  
Neeraj Sharma ◽  
Tilak Raj ◽  
Kamal Kumar Jangra

NiTi is a shape memory alloy, mostly employed in cardiovascular stents, orthopedic implants, orthodontic wires, micro-electromechanical systems and so on. The effective and net shape machining of NiTi is very critical for excellent response of this material in medical and other applications. The present experimental work on wire electrical discharge machining process identifies the influence of process parameters that affect the cutting rate, dimensional shift and surface roughness while machining of porous nickel–titanium (Ni40Ti60) alloy. Porous Ni40Ti60 alloy was produced in-house using powder metallurgy technique. Response surface methodology–based central composite rotatable design has been used for the planning of experiments on wire electrical discharge machining. Empirical relations have been developed between the process parameters (pulse on-time, pulse off-time, servo voltage and peak current) and response variables. Desirability approach has been used for optimizing the three response variables simultaneously. Confirmation experiments were also performed at the optimized settings and reflect a close agreement between the predicted and experimental values (percentage error varies from −6.13% to +6.85%). Using wire electrical discharge machining, NiTi alloy can be machined easily and successfully in single-cutting operation, but after the first cut in wire electrical discharge machining, a surface projection appears on work surface which is the unmachined material on work surface.

2015 ◽  
Vol 766-767 ◽  
pp. 902-907
Author(s):  
Bibin K. Tharian ◽  
B. Kuriachen ◽  
Josephkunju Paul ◽  
Paul V. Elson

Wire electrical discharge machining is one of the important non-traditional machining processes for machining difficult to machine materials. It involves the removal of material by the discrete electric discharges produced between the inter electrode gap of continuously moving wire electrode and the work piece. The ability to produce intricate profiles on materials irrespective of the mechanical properties made this process to be widely used in industries. The present study investigates the relationship of various process parameters in WEDM of AISI 202 stainless steel with brass electrode.The experiments were planned according to Taguchi’s L18 orthogonal array and experimental models were developed. The important process parameters identified for the present study were pulse on time, peak current, pulse off time, wire feed, wire tension, dielectric flushing pressure, servo feed and gap voltage. The surface roughness of the machined surface was measured as the process performance measure. Analysis of variance test has also been carried out to check the adequacy of the developed models and to identify the level of significance of each process parameters. In addition to the developed models, ABC optimization has been performed to identify the optimum parameter combination for minimum surface roughness and the obtained optimal process parameters are peak current 11 A, pulse on time 100 μs, pulse off time 49 μs, wire feed 4 m/min, wire tension 10 N, flushing pressure 12 kg/cm2, servo feed 2100 mm/min and set gap voltage 30 V. Finally the results were verified with the experimental results and found that they are in good agreement.


2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Md. Ashikur Rahman Khan ◽  
M. M. Rahman

Electrical discharge machining (EDM) produces complex shapes and permits high-precision machining of any hard or difficult-to-cut materials. The performance characteristics such as surface roughness and microstructure of the machined face are influenced by numerous parameters. The selection of parameters becomes complicated. Thus, the surface roughness (Ra) and microstructure of the machined surface in EDM on Grade 6 titanium alloy are studied is this study. The experimental work is performed using copper as electrode material. The polarity of the electrode is maintained as negative. The process parameters taken into account in this study are peak current (Ip), pulse-on time (Ton), pulse-off time (Toff), and servo-voltage (Sv). A smooth surface finish is found at low pulse current, small on-time and high off-time. The servo-voltage affects the roughness diversely however, a finish surface is found at 80 V Sv. Craters, cracks and globules of debris are appeared in the microstructure of the machined part. The size and degree of craters as well as cracks increase with increasing in energy level. Low discharge energy yields an even surface. This approach helps in selecting proper process parameters resulting in economic EDM machining. 


2020 ◽  
Vol 979 ◽  
pp. 3-9
Author(s):  
G. Ramanan ◽  
M.Madhu Kiran Reddy ◽  
V. Manishankar

The quality of machining through process parameters on the responses in wire electrical discharge machining (WEDM) is studied. This paper discusses the optimization of parameters of a process in WEDM machining with the application of the desirability approach on the basis of response surface methodology (RSM). Pulse on time, servo speed rate, discharge current, and pulse off time have been considered as influential factors. The established experimental data of AA7075 aluminium reinforced with 9% of activated carbon composite to analyze the process parameter effects on responses, like material removal rate (MRR) and surface roughness (SR). After machining multiple regression analysis is used to find the interaction among the process parameters is obtained. The optimal parameters were found using the desirability optimization methodologies as 10.43mm3/min and 3.32μm respectively. The performance of the optimization test confirmed that the proposed method in this study effectively improves the performance of the WEDM process.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2533
Author(s):  
Rakesh Chaudhari ◽  
Jay Vora ◽  
L.N.López de Lacalle ◽  
Sakshum Khanna ◽  
Vivek K. Patel ◽  
...  

In the current scenario of manufacturing competitiveness, it is a requirement that new technologies are implemented in order to overcome the challenges of achieving component accuracy, high quality, acceptable surface finish, an increase in the production rate, and enhanced product life with a reduced environmental impact. Along with these conventional challenges, the machining of newly developed smart materials, such as shape memory alloys, also require inputs of intelligent machining strategies. Wire electrical discharge machining (WEDM) is one of the non-traditional machining methods which is independent of the mechanical properties of the work sample and is best suited for machining nitinol shape memory alloys. Nano powder-mixed dielectric fluid for the WEDM process is one of the ways of improving the process capabilities. In the current study, Taguchi’s L16 orthogonal array was implemented to perform the experiments. Current, pulse-on time, pulse-off time, and nano-graphene powder concentration were selected as input process parameters, with material removal rate (MRR) and surface roughness (SR) as output machining characteristics for investigations. The heat transfer search (HTS) algorithm was implemented for obtaining optimal combinations of input parameters for MRR and SR. Single objective optimization showed a maximum MRR of 1.55 mm3/s, and minimum SR of 2.68 µm. The Pareto curve was generated which gives the optimal non-dominant solutions.


Author(s):  
T Vijaya Babu ◽  
B Subbaratnam

WEDM (Wire Electrical discharge machining) is a nonconventional machining processes used in complicated shapes with high accuracy which are not possible with other conventional methods .Stainless steel 304 is used in present experimental work. Experiments are completed using Taguchi’s method with L9 orthogonal array .The aim of this work is to optimize the WEDM process parameters by considering input parameters are pulse on time , pulse off time ,peak current and wire feed and experiments are conducted with help of input parameters at three levels and response output parameters are MRR (Material removal Rate) and Surface Roughness (SR).Setting of parameters using by Taguchi’s method.


2021 ◽  
Vol 8 ◽  
pp. 16
Author(s):  
Ipsita Nayak ◽  
Jaydev Rana

Wire electrical discharge machining (WEDM) is a popular non-conventional machining process used particularly for making extrusion dies, blanking punches, and tools especially requiring tight dimensional tolerances. Because of the process limitation, the rate of cutting and maintenance of close dimensional tolerance is a challenging task. Given the above facts, the present work has been focused on achieving the maximum possible cutting rate (VC) maintaining good dimensional accuracy and corner radius (RC). In the present research work, a multi-response optimization method (i.e. Taguchi based Utility approach) has been used to obtain an optimum set of input parameters such as pulse on time (TON), pulse off time (TOFF), servo voltage (SV), and wire feed rate (WF) resulting into a best overall cutting performance. Analysis of variance (ANOVA) is also used to find out the significant effect of each machining parameter on the cutting performance. The analysis reported in this paper will be helpful for industry personnel to select the best set of process parameters for achieving a good result without the use of any software or statistical analysis.


2015 ◽  
Vol 15 (4) ◽  
pp. 327-338 ◽  
Author(s):  
K. Anand Babu ◽  
P. Venkataramaiah

AbstractIn recent days, the silicon carbide particulate reinforced aluminium metal matrix composites are most promising material in various engineering applications due to their strength to weight ratio, wear resistance and thermal resistance over the non-reinforced alloys. However, these materials are very difficult to cut by conventional machining methods due to the presence of silicon carbide particles. To overcome this limitation, the wire electrical discharge machining (WEDM) is employed to machine these composites. The aim of this study is to optimize the process parameters in wire electrical discharge machining (WEDM) of Al6061/SiCp composite using AHP-TOPSIS method. Al 6061/2% SiCp/3 µm particulate metal matrix composite is fabricated by using stir casting method and the uniformity of particle distribution was analyzed by SEM. Taguchi L18 orthogonal array is designed by considering various process parameters viz. Wire Type (WT), Pulse ON Time (T ON), Pulse OFF Time (T OFF), Wire Feed rate (WF) and Sensitivity (S) for conducting WEDM experiments. The obtained experimental results were analyzed and the results revealed that Sensitivity (S) is the prevailing factor on the response characteristics of WEDM followed by pulse ON time (T ON), wire feed rate (WF), Wire Type (WT) and pulse OFF time (T OFF).


Author(s):  
G Selvakumar ◽  
KG Thiruppathi Kuttalingam ◽  
M Selvaraj ◽  
J Manohar

In this study, path modification strategy is used to improve the accuracy of the die corner produced in wire electrical discharge machining process. Based on Taguchi’s L18 array, experiments are performed on Monel 400 alloy. The influence of the machine-controllable factors such as wire tension, open-circuit voltage, pulse-on time, pulse-off time and additional travel and uncontrollable factors namely corner angles and flushing nozzle height on the performance measures such as surface roughness, cutting speed, and corner error are studied. The outcome of this study reveals that the path modification value in terms of additional travel of 0.5 mm improves the corner accuracy of the profile by 35% as compared to the profile machined without adopting path modification strategy. The analyses of scanning electron micrographs are carried out. Finally, an optimal technological guideline is reported for ready industrial use.


2020 ◽  
Vol 8 (5) ◽  
pp. 3045-3052

Wire Electrical Discharge Machining (WEDM) is a widely used non-traditional machining process used for machining of hard and difficult-to-machine materials. Proper selection of machining parameters in WEDM is required for better output performance, such as Material Removal Rate (MRR), Wire Wear Rate (WWR) and Surface Roughness (SR) etc. In the present paper, Pulse ON time, Pulse OFF time, Peak Current, Spark Voltage, Wire Feed and Wire Tension were taken as the input parameters to optimize MRR, WWR and SR. A set of 27 experiments were performed as per Taguchi Design. A Fuzzy model has been proposed to select the optimum values of machining parameters. The proposed fuzzy model was found to predict the experimental values with more than 90 percent accuracy.


2015 ◽  
Vol 760 ◽  
pp. 551-556 ◽  
Author(s):  
Oana Dodun ◽  
Laurenţiu Slătineanu ◽  
Margareta Coteaţă ◽  
Vasile Merticaru ◽  
Gheorghe Nagîţ

Wire electrical discharge machining is a machining method by which parts having various contours could be detached from plate workpieces. The method uses the electrical discharges developed between the workpiece and the wire tool electrode found in an axial motion, when in the work zone a dielectric fluid is recirculated. In order to highlight the influence exerted by some input process factors on the surface roughness parameter Ra in case of a workpiece made of an alloyed steel, a factorial experiment with six independent variables at two variation levels was designed and materialized. As input factors, one used the workpiece thickness, pulse on time, pulse off-time, wire axial tensile force, current intensity average amplitude defined by setting button position and travelling wire electrode speed. By mathematical processing of the experimental results, empirical models were established. Om the base of a power type empirical model, graphical representations aiming to highlight the influence of some input factors on the surface roughness parameter Ra were achieved. The power type empirical model facilitated establishing of order of factors able to exert influence on the surface roughness parameter Ra at wire electrical discharge machining.


Sign in / Sign up

Export Citation Format

Share Document