scholarly journals Enhancement of Surface Roughness and Corrosion Resistance of Wedmed Al 7075 Alloy

2019 ◽  
Vol 8 (4) ◽  
pp. 4944-4947

An alloy of Aluminium has good properties and strong would be ideal for many applications. Among all the series of aluminium alloys, Al 7075 is extensively used in aircraft structures, gear shafts, and automotive industry because of its high strength and good corrosion resistance. The machining of Al 7075 can be done under annealed conditions and lubricants are used for operations. In the present work, Al 7075 was machined by using Wire Electric Discharge Machine (WEDM) and investigated the effect of operating parameters on reponses. The surface roughness and corrosion resistance are considered as responses. The operating parameters of WEDM considered in this work are pulse ON time, pulse OFF time, wire feed and servo voltage. Experiments were conducted according to the Taguchi’s design of orthogonal array L18 (21 x33 ). The values of surface roughness and corrosion pit potentials were observed for each experiment to understand the relationship. Multi-objective optimization for these process parameters has been carried out by Grey Relation Analysis (GRA). From this technique, the optimum combination of process parameters are obtained and corresponding values of surface roughness and corrosion pit potentials are found out. To validate the response table for grey relation grade obtained from GRA, Taguchi analysis was carried out which shows that the pulse on time is the most influencing parameter followed by pulse off time, wire feed and servo voltage.

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.


2018 ◽  
Vol 7 (2) ◽  
pp. 36-42
Author(s):  
Ramandeep Singh ◽  
Ashok Kumar

Wire EDM can machine hard materials as well as alloys. Thus this study aims to analyze the effect of process parameters in WEDM on EN31 and EN19 alloy steels. The parameters selected for the optimization were Work material, Pulse on Time, Pulse off Time, Current, Voltage and Wire Feed for improvement in surface roughness. Taguchi L18 Orthogonal array was used for the best combination of experiment. The output responses were analyzed by ANOVA (Analysis of variance). The ANOVA result indicated that there is a significant effect on improvement in surface roughness when machining with all these six input parameter and coated wire. According to the present investigation, voltage was found to be the most significant factor followed by Ton and current, which affect the improvement in surface roughness.


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. 


2014 ◽  
Vol 550 ◽  
pp. 53-61
Author(s):  
R.Arun Bharathi ◽  
P.Ashoka Varthanan ◽  
K. Manoj Mathew

The objective of the present work is to predict the optimal set of process parameters such as peak current (IP), pulse on/off time (TON/TOFF) and spark gap voltage (SV) to achieve minimum Surface roughness (Ra), wire consumption rate (WCR) and maximum material removal rate (MRR). In this work, experiments were carried out by pulse arc discharges generated between ZnO coated brass wire and specimen (IS2062 steel) suspended in deionized water dielectric. The experiments were designed based on the above mentioned four factors, each having three levels. Custom design based Response Surface Methodology (RSM) is used in this research. 21 runs of experiments were constructed based on custom design procedure and results of the experimentation were analyzed analytically as well as graphically. Moreover the surface roughness after machining was measured by Taylor Hobson Surtronic device. Second order regression model has been developed for predicting Ra, WCR and MRR in terms of interactive and higher order machining parameters through RSM, utilizing relevant experimental data as obtained through experimentation. The research outcome identifies significant parametersand their effect on process performance on IS2062 steel. The results revealed that peak current, pulse on-time and their interactions have significant effects on Ra, whereas pulse off time and peak current have significant effects on MRR and it is also observed that peak current and interaction between peak current and pulse off time have significant effects on WCR. The adequacy of the above proposed models has been tested through the analysis of variance (ANOVA).


2014 ◽  
Vol 23 (3) ◽  
pp. 096369351402300
Author(s):  
D. Satishkumar ◽  
M. Kanthababu

Metals or alloys when reinforced with more than one reinforcement materials are generally considered as hybrid metal matrix composites (MMCs). The superior properties of the hybrid MMCs deter its wide applications due to the difficulty in machining. Wire electrical discharge machining (WEDM) is an effective unconventional machining process which can be used to machine difficult to machine materials. This work is aimed towards optimizing the WEDM parameters to achieve better surface roughness ( Ra) during machining of stir cast unreinforced A17075 alloy and A17075/B4C/Al2O3 based hybrid MMCS. The experiments were carried out as per central composite design of response surface methodology (RSM). It is observed that all the process parameters such as pulse-on time ( TON), pulse-off time ( TOFF), wire feed (F), gap voltage (V) considered in this work were significant.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Mangesh R. Phate ◽  
Shraddha B. Toney ◽  
Vikas R. Phate

Aluminium silicate metal matrix composite (AlSiC MMC) is satisfying the requirement of material with good mechanical, thermal properties, and good wear resistance. But the difficulties during the machining are the main hurdles to its replacement for other materials. Wire electric discharge machining (WEDM) is a very effective process used for this type of difficult-to-cut material. So an effort has been taken to find out the most favourable level of input parameters for WEDM of AlSiC (20%) composite using a Taguchi-based hybrid grey-fuzzy grade (GFG) approach. The plan for experimentation is designed using Taguchi’s L9 (23) array. The various process parameters considered for the investigation are pulse on time (TON), pulse off time (TOFF), wire feed rate (WFR), and peak current (IP). Surface integrity such as surface roughness measured during the different types of cutting (along straight, inclined, and curvature directions) is considered in the present work. Grey relational analysis (GRA) pooled with the fuzzy logic is effectively used to find out the grey-fuzzy reasoning grade (GFRG). The Taguchi approach is coupled with the GFRG to obtain the optimum set of process parameters. From the experimental findings, it has been observed that the most economical process parameters for WEDM of AlSiCp20 were the pulse on time is 108 microsec, pulse off time is 56 microsec, wire feed rate (WFR) is 4 m/min, and peak current (IP) is 11 amp. From the analysis of variance (ANOVA), it is observed that the pulse on time is the foremost influencing parameters that contribute towards GFRG by 52.61%, followed by the wire feed rate (WFR) 38.32% and the current by 5.45%.


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).


2020 ◽  
Vol 7 ◽  
pp. 30
Author(s):  
Kingshuk Mandal ◽  
Dipankar Bose ◽  
Souren Mitra ◽  
Soumya Sarkar

Process parameters selection is a critical task in wire electro-discharge machining (WEDM). The parameter settings would vary when a material to be machined is changed. In the present study, experimental investigation has been carried out for appropriate selection of process parameters in WEDM of Al 7075. It has been perceived that pulse on time (Ton), arc on time (Aon) pulse off time (Toff), arc off time (Aoff), servo sensitivity (Sc), wire tension (Wt) and servo voltage (Sv) are the major influencing factors on machining speed (Vc), corner error (Ce) and surface roughness (Ra) for this alloy. It is also observed that selected seven process parameters are essential for effective machining of Al 7075 alloy. Finally, three-dimensional (3D) surface topography has been analysed to determine the characteristics of the machined surface.


2018 ◽  
Vol 172 ◽  
pp. 04010
Author(s):  
A. Muniappan ◽  
R. Senthilkumar ◽  
V. Jayakumar ◽  
S. Venkata Ravikumar ◽  
P. Sai Tarunkumar

The present study focused on the multiple regression modeling and predicting the surface roughness of the Aluminum hybrid composite during the WEDM process. The hybrid MMC was manufactured by process named as stir casting utilizing particulates of Silicon carbide and graphite each in Al6061 combination. The analyses were outlined with Taguchi L27 design matrix. Mathematical relationships between the surface roughness and WEDM cutting parameters (Pulse on time, Pulse off time, current, gap voltage, wire speed and wire tension) have been investigated. The results show that the multiple regression analysis is a successful method for developing a mathematical model to predict the surface roughness. The optimum value of process parameters for the predicted optimum value of surface roughness (1.285) is pulse on time 106 units (Level 1), pulse off time 60 units (Level 3), peak current 90 units (Level 2), gap set voltage 50 units (Level 3), wire speed3 units (Level 1) and wire tension 12 units (Level 3).The optimum results are adopted in validation study and the results based on WEDM process responses can be effectively improved.


2018 ◽  
Vol 1 (93) ◽  
pp. 12-31
Author(s):  
A.M. Takale ◽  
N.K. Chougule

Purpose: This paper focuses on the investigation on the effect of process parameters such as pulse on time (Ton), pulse off time (Toff), spark gap set voltage (SV), wire feed (WF) and wire tension (WT) on the responses such as the material removal rate (MRR), surface roughness (SR), kerf width (KW) and dimensional deviations (DD) of Ti49.4Ni50.6 (at.%) shape memory alloy (SMA) machined by WEDM. Ti-Ni SMA has fascinating properties and biocompatibility, it is considered for the present work. Design/methodology/approach: As per the Taguchi technique, L18 orthogonal array experiments on WEDM have been performed. The signals to noise (S/N) ratio plots are analysed to determine the influence of process parameters. Analysis has been tested through analysis of variance (ANOVA). SEM images are taken to confirm the results offering better surface quality. Findings: It was observed that pulse on time is the most significant factor for MRR and SR with the contribution of 35.69% and 59.02% respectively. The SV is a significant factor for KW and DD with contributions of 47.35% and 30.03% at 95% confidence level. A multi-response optimization has been carried out using grey relational analysis (GRA) to determine the optimum combination of process parameters. It is shown that, through GRA the optimal machining parameter setting such as A2B1C3D2E1 i.e. (pulse on time of 115 machine unit, pulse off time of 20 machine unit, spark gap set voltage of 90 V, wire feed of 6 m/min and wire tension of 3 machine unit) has been observed for maximum MRR and minimum SR, KW and DD. Young’s modulus checked for biocompatibility. Research limitations/implications: Heat treatment process like annealing is found to be most suitable to recover shape memory effect of WEDMed samples.


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