The process is very common in manufacturing of injection molds. Appliable from fine highaccuracy machining to highproductivity jobs using large electrode. Most nc today is computer or computerized numerical control cnc, in which computers play an integral part of the control. Electron beam machining ebm introduction electron beam machining is a thermal process used for metal removal during the machining process. Diesinker edm and wire cut electric discharge machining wedm 21.
Numerical control wikipedia, the free encyclopedia. The main attraction of edm over traditional machining processes such as metal cutting using different tools and grinding is that this technique utilises thermoelectric process to erode undesired materials from the workpiece by a series of. The electrode is a thin wire, with diameters that typically range from. Machining centers machining center highly automated machine tool capable of performing multiple machining operations under cnc control.
Pulsed arc discharges occur in the gap, filled with a nonconducting medium. Today robots are available that can feed various machines, such as a milling machine, wire edm, and a ram edm. Commercial kerosene was used as a dielectric fluid. The book also describes the development of electrical discharge machining edm, the edm system and process, the edm sparking system, the power supply generator, spark voltage, electrode servo systems, dielectric systems, ionization and electrode wear, chips, the edm surface, dc arcing, different kinds of edm, automatic servo systems. References a b theoretical models of the electrical discharge machining process. During this machining process, a small portion of metals is also eroded away, leaving a small cater. In the electrical beam machining, electrical energy is used to generate the electrons with high energy. Dwedm is an environmentalfriendly machining process where gas is used as the dielectric fluid instead of liquid. History of edm in1770s, discovered by joseph priestly. The power needed to operate the ecm is obviously electrical. Check out the pdf notes and ebook for the subject electrical machine 1 as part of the electrical engineering branch.
Paul,department of mechanical engineering, iit kharagpur. The changes are made keeping the original flavor of the book intact, that is, indepth coverage of fundamental concepts. This ebook of electrical machine 1 is very useful and can help you score really well during your exam. In this ebook you will find covering the both electrical discharge machining and electrochemical machining. Pdf special electrical machines nptel notes r anitha. The bubble density at the tool increases with an increase in supply voltage, and, when it becomes sufficiently high, substantial constriction of the current path takes place at the interface of. The electrode used is 15 mm in diameter and 50 mm in height. Material is removed from the work piece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to.
In the ecm process, hydrogen is liberated and gets accumulated at the cathode tool. Application in wide range from parts manufacturing to ultrahigh accurate mold making. Electrical discharge machines mitsubishi electric fa. Edm machining process is also known as spark erosion machining. Nontraditional and hybrid machining processes by hassan abdelgaward elhofy book is a good reference for both nontraditional and hybrid machining processes. Developed in the mid 1970s in the mid 1980s, the edm techniques were transferred to a machine tool today,it is a viable technique that helped shape. There are many specifications to this power, the current density must be high, the difference between the tool and the work piece must be low for higher accuracy, thus the voltage must be low to avoid a short circuit and the control system uses. A thermo electric model of material removal during electric discharge machining. Electric discharge machining edm process video lecture. Electrical discharge machining edm is one of the most extensively used nonconventional material removal processes. Join our community just now to flow with the file dc machine and make our shared file collection even more complete and exciting. On the analysis of the electrochemical spark machining process. Sharma, department of mechanical engineering, iit roorkee.
Electric discharge machining edm is a thermo electrical nontraditional machining process in which a series of discrete spark is generated between the electrodes under controlled machining condition. Mechanical machining ultrasonic machining usm and waterjet machining wjm are typical examples of single action, mechanical non traditional machining processes. Other machining processes theres more than one way to skin a cat, as the old expression goes. Aim of the presentation give brief information about electro chemical machining process show the ecms working principles and tools define the advantages and disadvantages brief informations about application areas, economics, products and developments. Electrical discharge machining edm is one of the most widely used nontraditional machining processes. Machining a material removal process in which a sharp cutting tool is used to mechanically cut away material so that the desired part geometry remains most common application.
Electrical discharge machining, edm is one of the most accurate manufacturing processes available for creating complex or simple shapes and geometries within parts and assemblies. Electric discharge machining edm ppt download in wire electrical discharge machining wedm, also known as wirecut edm and wire cutting, a thin singlestrand metal wire, usually brass, is fed through the workpiece, submerged in a tank of dielectric fluid, typically deionized water. Electrical machines 3 notes em iii notes this subject is an extension of previous machines courses. Electrochemical machining ecm seminar with pdf report. The process can be as simple as using a small diameter metal tube to cut a precise hole in a metal block to using a carved graphite block to machine a. In the electron beam machining process, a high velocity focused beam of electrons are used to remove the.
Pdf electric machine by ashfaq husain book free download. It deals with the detailed analysis of synchronous generators and motors which are the prime source of electrical power generation and its utilities. In electric discharge machining process an arc is produced when two currentcarrying wires are shortcircuited. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Edm electrical discharge machining is a way of cutting metal using electricity, similar to a plasma cutter except under water. Similarly, theres typically more than one way to cut parts. Singh, balbir singh modern machining processes presents unconventional machining methods which are gradually commercial acceptance.
It is an electrothermal machining process where electrical energy is used to generate electrical spark and material removal mainly occurs due to thermal energy of the spark. The machining was generally carried out for a fixed time interval and the amount of metal removed was measured by taking the difference in weights of the workpiece before and after electrical discharge machining. Electrical discharge machining is the process of metal removal from the work surface due to an erosion of metal caused by electric spark discharge between the two electrodes tool cathode and the work anode. Download electric machine by ashfaq husain electric machines, is intended for third and fourth year ug students and first year pg students of electrical engineeringupdated with latest scientific advancements. The heattreated tool steels material falls in the difficulttocut material group when using conventional machining process. Finite element analysis of electric discharge machining. Unit iii electrical energy based processes 8 electric discharge machining edm working principleequipmentsprocess parameters surface finish and mrr electrode tool power and control circuitstool wear dielectric flushing wire cut edm applications. Lecture series on manufacturing processes ii by prof. Numerical control nc is the automation of machine tools that are operated by precisely programmed commands encoded on a storage medium, as opposed to controlled manually by hand wheels or levers, or mechanically automated by cams alone. This process works on the principle of of faradays laws of. The machining medium is solid grains suspended in an abrasive slurry in the former,while a fluid is employed in the wjm process. Micro electric discharge machining micro edm is a nontraditional machining process which can be used for drilling micro holes in high strength to weight ratio materials like titanium super alloy. Electron beam machining ebm diagram, working, advantages. Advanced machining processes by hassan abdelgaward elhofy.
The main topics covered in these lecture notes for electrical machine 1. The variable mass, cylindrical plasma model singh, a. Edm works by eroding material in the path of electrical discharges that form an arc between an electrode tool and the work piece. Study of the parameters in electrical discharge machining. Understanding electrical discharge machining 29 automation and edm here is an example in which one may use their imagination to become more competitiveusing automatic production cells.
Debaprasad kastha, department of electrical engineering, iit kharagpur. The noteworthy feature of electrolysis is that electrical energy is used to produce a chemical reaction, therefore, the machining process based on this principle is known as electrochemical machining ecm. Compared with conventional machining from basic cnc turning all the way up to 5axisedm has certain advantages and disadvantages. Manufacturing knowledge menu edm manufacturing services edm manufacturing equipment. However, the process control parameters of the machine have to.