Join our community just now to flow with the file dc machine and make our shared file collection even more complete and exciting. 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. Edm works by eroding material in the path of electrical discharges that form an arc between an electrode tool and the work piece. 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. In the ecm process, hydrogen is liberated and gets accumulated at the cathode tool.
Wire cut edm, also known as wire electrical discharge machining, or wire edm is a method of cutting or shaping conductive materials with a thin electrode that follows a precisely programmed path. Electrical discharge machining edm is one of the most widely used nontraditional machining processes. The heattreated tool steels material falls in the difficulttocut material group when using conventional machining process. Check out the pdf notes and ebook for the subject electrical machine 1 as part of the electrical engineering branch. Study of the parameters in electrical discharge machining.
Lecture series on manufacturing processes ii by prof. 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. 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. The variable mass, cylindrical plasma model singh, a. History of edm in1770s, discovered by joseph priestly. 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.
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. Nontraditional and hybrid machining processes by hassan abdelgaward elhofy book is a good reference for both nontraditional and hybrid machining processes. Edm electrical discharge machining is a way of cutting metal using electricity, similar to a plasma cutter except under water. Nptel transformers video lectures, electrical machines lectures, dc machines video, nptel video lectures, nptel online courses, youtube iit videos nptel courses. 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. Manufacturing knowledge menu edm manufacturing services edm manufacturing equipment. 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. In the electron beam machining process, a high velocity focused beam of electrons are used to remove the. Finite element analysis of electric discharge machining. Numerical control wikipedia, the free encyclopedia. Electric discharge machining edm process video lecture. Application in wide range from parts manufacturing to ultrahigh accurate mold making. Sharma, department of mechanical engineering, iit roorkee.
However, the process control parameters of the machine have to. In the electrical beam machining, electrical energy is used to generate the electrons with high energy. Compared with conventional machining from basic cnc turning all the way up to 5axisedm has certain advantages and disadvantages. Advanced machining processes by hassan abdelgaward elhofy. 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. Electrochemical machining ecm seminar with pdf report. Appliable from fine highaccuracy machining to highproductivity jobs using large electrode.
Singh, balbir singh modern machining processes presents unconventional machining methods which are gradually commercial acceptance. Other machining processes theres more than one way to skin a cat, as the old expression goes. Dwedm is an environmentalfriendly machining process where gas is used as the dielectric fluid instead of liquid. It deals with the detailed analysis of synchronous generators and motors which are the prime source of electrical power generation and its utilities. Commercial kerosene was used as a dielectric fluid. The power needed to operate the ecm is obviously electrical. 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. Today robots are available that can feed various machines, such as a milling machine, wire edm, and a ram edm. Automatic tool changer pallet shuttles automatic workpart positioning cnc turning center. The process is very common in manufacturing of injection molds. 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. Machining centers machining center highly automated machine tool capable of performing multiple machining operations under cnc control. 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. Debaprasad kastha, department of electrical engineering, iit kharagpur.
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. Pdf special electrical machines nptel notes r anitha. A thermo electric model of material removal during electric discharge machining. 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. 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. Diesinker edm and wire cut electric discharge machining wedm 21. Similarly, theres typically more than one way to cut parts. During this machining process, a small portion of metals is also eroded away, leaving a small cater. All aspects of mechanical, electrochemical and thermal processes are comprehensively covered. Pulsed arc discharges occur in the gap, filled with a nonconducting medium. 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. Electron beam machining ebm introduction electron beam machining is a thermal process used for metal removal during the machining process. This process works on the principle of of faradays laws of.
Electrical discharge machines mitsubishi electric fa. Electron beam machining ebm diagram, working, advantages. Edm machining process is also known as spark erosion machining. 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. The electrode is a thin wire, with diameters that typically range from. Pdf electric machine by ashfaq husain book free download. Mechanical machining ultrasonic machining usm and waterjet machining wjm are typical examples of single action, mechanical non traditional machining processes. The electrode used is 15 mm in diameter and 50 mm in height. Electrical discharge machining edm is one of the most extensively used nonconventional material removal processes. Electrical machines 3 notes em iii notes this subject is an extension of previous machines courses. The main topics covered in these lecture notes for electrical machine 1. In electric discharge machining process an arc is produced when two currentcarrying wires are shortcircuited. Paul,department of mechanical engineering, iit kharagpur.
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. On the analysis of the electrochemical spark machining process. In this ebook you will find covering the both electrical discharge machining and electrochemical machining. Most nc today is computer or computerized numerical control cnc, in which computers play an integral part of the control. 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. The changes are made keeping the original flavor of the book intact, that is, indepth coverage of fundamental concepts. Electrical discharge machine the traditional machining processes rely on harder tool or abrasive material to remove the softer material whereas nontraditional machining processes such as edm uses electrical spark or thermal energy to erode unwanted material in. 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.