scholarly journals OPTIMASI KETEBALAN LAPISAN RECAST, KEKASARAN PERMUKAAN DAN LAJU PENGERJAAN MATERIAL PADA PROSES PEMESINAN WIRE-EDM MENGGUNAKAN METODE TAGUCHI-GREY FUZZY

2018 ◽  
Vol 9 (2) ◽  
pp. 985-992
Author(s):  
Pathya Rupajati ◽  
Perak Samosir ◽  
M. Kurniadi Rasyid

Proses wire-electrical discharge machining (wire-EDM) sering digunakan dalam industri manufaktur. Parameter pemesinan yang terdapat dalam wire-EDM di antaranya, arc on time, on time, servo voltage dan wire feed. Pengaturan level yang tidak tepat dalam proses ini akan menyebabkan lapisan recast dan kekasaran permukaan yang tinggi serta laju pengerjaan material yang rendah. Metode optimasi Taguchi dikombinasikan dengan grey fuzzy merupakan metode yang digunakan dalam penelitian ini. Rancangan perobaan pada penelitian ini menggunakan matriks orthogonal array L9 karena memvariasikan empat parameter proses pemesinan dengan masing-masing menggunakan tiga level. Replikasi pada eksperimen ini dilakukan sebanyak dua kali. Karakteristik kualitas respon untuk tebal lapisan recast dan kekasaran permukaan adalah semakin kecil semakin baik, sedangkan untuk laju pengerjaan material adalah semakin tinggi semakin baik. Hasil penelitian ini menunjukkan bahwa wire feed dan on time merupakan parameter proses yang paling signifikan dalam menghasilkan multirespon yang optimal. Hasil kombinasi parameter proses yang menghasilkan kualitas respon yang optimal adalah arc on time diseting pada 3 A, on time diseting pada 8 µs, servo voltage diseting pada 100 V dan wire feed diseting pada 60 mm/min.

Author(s):  
Kamlesh Joshi ◽  
Upendra Bhandarkar ◽  
Indradev Samajdar ◽  
Suhas S. Joshi

Slicing of Si wafers through abrasive processes generates various surface defects on wafers such as cracks and surface contaminations. Also, the processes cause a significant material loss during slicing and subsequent polishing. Recently, efforts are being made to slice very thin wafers, and at the same time understand the thermal and microstructural damage caused due to sparking during wire-electrical discharge machining (wire-EDM). Wire-EDM has shown potential for slicing ultra-thin Si wafers of thickness < 200 μm. This work, therefore, presents an extensive experimental work on characterization of the thermal damage due to sparking during wire-EDM on ultra-thin wafers. The experiments were performed using Response surface methodology (RSM)-based central composite design (CCD). The damage was mainly characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The average thickness of thermal damage on the wafers was observed to be ∼16 μm. The damage was highly influenced by exposure time of wafer surface with EDM plasma spark. Also, with an increase in diameter of plasma spark, the surface roughness was found to increase. TEM micrographs have confirmed the formation of amorphous Si along with a region of fine grained Si entrapped inside the amorphous matrix. However, there were no signs of other defects like microcracks, twin boundaries, or fracture on the surfaces. Micro-Raman spectroscopy revealed that in order to slice a wafer with minimum residual stresses and very low presence of amorphous phases, it should be sliced at the lowest value of pulse on-time and at the highest value of open voltage (OV).


2015 ◽  
Vol 1120-1121 ◽  
pp. 1325-1329 ◽  
Author(s):  
Felipe B. Nishida ◽  
Larissa S. Marquardt ◽  
Valquíria Y.S. Borges ◽  
Paulo H.D. Santos ◽  
Thiago Antonini Alves

In this research, a heat pipe with grooves was experimentally analyzed for the application in thermal management of electronic packaging. The heat pipe was produced by a copper tube with an outer diameter of 9.45 mm, length of 205 mm, and capillary structure composed by axial grooves with average diameter of 220 μm. The grooves were manufactured using wire electrical discharge machining (wire-EDM). The working fluid used was de-ionized water. The condenser was cooled by air forced convection and the evaporator was heated using an electrical resistor. This heat pipe was tested horizontally to increasing heat loads varying from 5 to 15 W. The experimental results showed that the heat pipe worked successfully.


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.


Alloy Digest ◽  
2005 ◽  
Vol 54 (4) ◽  

Abstract Crucible S7 XL is a double-refined high-purity grade of S7 tool steel (see Alloy Digest TS-543, July 1996) designed specifically for ease of wire electrical discharge machining (EDM) operations, improved consistency in texturizing of plastic injection molds, and superior shock resistance compared to conventional S7. Typical applications include plastic injection molds, punches and dies by wire EDM, and heavy impact tools. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on wear resistance as well as heat treating, machining, joining, and surface treatment. Filing Code: TS-562. Producer or source: Crucible Service Centers. Originally published November 1998, revised 2005.


2001 ◽  
Author(s):  
Jun Qu ◽  
Albert J. Shih ◽  
Ron Scattergood

Abstract Results of applying the wire Electrical Discharge Machining (EDM) process to generate precise cylindrical forms on hard, difficult-to-machine materials are presented. The design of an underwater rotary spindle is first introduced. The spindle is added to a conventional two-axis wire EDM machine to enable the generation of free-form cylindrical geometry. Mathematical models for material removal rate and surface finish in cylindrical wire EDM of the free-form cylindrical workpiece are derived. Experiments are conducted for cylindrical and 2D wire EDM of brass and carbide work-materials. Comparing to the conventional 2D wire EDM of the same work-material, higher maximum material removal rates could be achieved in the cylindrical wire EDM. The surface finish and roundness of parts generated by cylindrical wire EDM at different part rotational speeds and wire traverse speeds are measured and analyzed.


2002 ◽  
Vol 124 (3) ◽  
pp. 702-707 ◽  
Author(s):  
Jun Qu ◽  
Albert J. Shih ◽  
Ronald O. Scattergood

Results of applying the wire Electrical Discharge Machining (EDM) process to generate precise cylindrical forms on hard, difficult-to-machine materials are presented. The design of a precise, flexible, and corrosion-resistant underwater rotary spindle is first introduced. A detailed spindle error analysis identifies the major sources of error at different frequency spectrum. The spindle has been added to a conventional two-axis wire EDM machine to enable the generation of free-form cylindrical geometries. The mathematical model for material removal rate of the free-form cylindrical wire EDM process is derived. Experiments were conducted to explore the maximum material removal rate for cylindrical and 2D wire EDM of carbide and brass work-materials. Compared to the conventional 2D wire EDM of the same work-material, higher maximum material removal rates may be achieved in the cylindrical wire EDM, possibly due to better debris flushing condition.


2016 ◽  
Vol 106 (06) ◽  
pp. 430-438
Author(s):  
K. Prof. Oßwald ◽  
D. Murnberger ◽  
T. Kappler ◽  
G. Sedlmayr

Diese Untersuchung beschäftigt sich mit einer in den westlichen Industrienationen kaum bekannten Variante des Drahterodierens. Es wird zunächst ein Überblick über die Merkmale der Technologie (beispielsweise Aufbau, verwendeter Draht, Prozessflüssigkeit) gegeben, die sich teilweise deutlich von der konventionellen Technik unterscheiden. Des Weiteren werden die Verläufe von Strom und Spannung des Prozesses gemessen sowie die gefertigten Werkstückoberflächen untersucht. &nbsp; This study deals with a variant of Wire Electrical Discharge Machining that is barely known in western industrialized countries. An overview of this technology‘s characteristics (setup, wire, fluid) is given, some of which are significantly different from conventional wire EDM (Electro Discharge Machining) technology. Furthermore, current and voltage profiles of the HSWEDM (High Speed Wire Electrical Discharge Machining) pulses are analyzed as well as the machined work piece surfaces.


2011 ◽  
Vol 314-316 ◽  
pp. 1727-1733
Author(s):  
Hong Ping Luo ◽  
Zhi Xiong Zhou ◽  
Yong Jun Zhang ◽  
Zhong Ning Guo

Wire electrical discharge machining (Wire EDM) cutting of flexures for a rotary flexural bearing fabrication is developed. The results of FEA calculation and theoretical analysis show that one of the main factors affecting flexures’ machining is the weak torsional stiffness of the bearing cage, thus excessive deflections due to machining stress, heat generation and spark-induced vibrations may occur. To minimize flexure deflection during the machining process, a specially designed fixture is utilized. Other technical measures, including residual stress relief before and after Wire EDM cutting, reasonable cutting sequence planning, multiple-cutting (i.e., rough cut followed by several trim cuts) etc., are also adopted for cutting. Dimensional accuracy of ±5µm was obtained over the 150µm thickness for the bearing flexures, a variation of less than 3µm was achieved for the flexures of opposing sides, and surface roughness of better than Ra 0.3μm was obtained for the flexures of the entire bearing cage. These results show the validity of measures aforementioned.


2020 ◽  
Vol 24 (2 Part A) ◽  
pp. 701-711
Author(s):  
Nishida Baptista ◽  
Larissa Krambeck ◽  
Dos Dias ◽  
Alves Antonini

This work presents the use of electrical discharge machining (EDM) technology for manufacturing of three different types of axial microgrooves in heat pipes. This specific process, called wire electrical discharge machining (wire-EDM), allows the fabrication of microgrooves on the inner wall of a heat pipe with accuracy. Different from other capillary structures, such as composite wick and screen mesh, the material is removed from the pipe?s container in order to conceive the capillary structure, which contributes with the mass reduction of the passive two-phase heat transfer device. The heat pipes were manufactured from a straight copper pipe with the external diameter of 9.45 mm, the inner diameter of 6.20 mm, and a total length of 200 mm. Three types of axial microgrooves were manufactured for constant width (35 ?m) and varying the depth (from 30-48 ?m), and thickness (from 35-70 ?m). The number of microgrooves was also varied from 21-32 microgrooves. Water was used as the working fluid and the loading filling ratio was 60% of the evaporator volume. The condenser was cooled by air forced convection, the adiabatic section was insulated and the evaporator was heated by an electrical resistor and it was insulated from the environment with aeronautic thermal insulation. The thermal performance of the heat pipes are analyzed based on experimental results, so the heat pipes were tested at the horizontal and different inclinations under different low heat loads (from 5-50 W or a heat flux from 0.21-2.10 W/cm2). The experimental results showed that the axial microgrooves manufactured by the wire-EDM process worked satisfactorily in all analyzed cases and microgrooves of Type 1 showed a better thermal performance when compared with the others.


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).


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