Introduction to nontraditional machining iit kanpur. An electric spark discharge is generated across the two terminals. Electric discharge machining machining electricity free. 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. Non traditional manufacturing processes an overview. Machined surfaces are stress and burr free having good surface finish 5. The variable mass, cylindrical plasma model singh, a. The more the product characteristic deviates from the target value, greater is the loss. The changes are made keeping the original flavor of the book intact, that is, indepth coverage of fundamental concepts. Electrical discharge machining is a method of removing metal using an electric sparks, similar to a plasma cutter but on a much smaller scale and under water. In recent years, the use of edm has increased significantly in industries, mainly due to the extensive use of hard and difficulttocut materials, i. During edm, the temperature developed at the point of spark is of the order of.
Thus the process makes use of electric energy to cut metal to desired shape. Lecture 19 electric discharge machining edm process digimat. The introduction of abrasives to the fluid jet enhances the. Relaxing studying music, brain power, focus concentration music. Nptel provides elearning through online web and video courses various streams. It can be used for any hard material and even in the heattreated condition. Rohani, parametric study of powder mixed electrical discharge machining and mathematical modeling of sisic using copper electrode, advanced materials research, vol. Introduction to electric discharge machining edm 2.
Wire electrical discharge machining has become an important nontraditional machining process, as it provides an effective solution for producing components made of difficulttomachine materials. The loss must be zero when the quality characteristic of a product meets its target value. Electrical discharge machining article about electrical. The mechanism of material removal is same as the common edm process. The main attraction of edm over traditional machining processes such. This is also called spark erosion or spark machining process. Electric discharge machining edm working principleequipmentsprocess parameters surface finish and mrr electrode tool power and control circuitstool wear dielectric flushing wire cut edm applications. Role of tool electrode and dielectric fluids in edm 6. Sharma, department of mechanical engineering, iit roorkee. Diesinker edm and wire cut electric discharge machining. Working principle of electric discharge machining electric discharge machining process is carried out in presence of dielectric fluid which creates path for discharge. Nptel electrical engineering electrical machines ii nptel provides elearning through online web and video courses various streams. 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.
Electrical discharge machining is a machining method primarily used for hard metals or those that would be very difficult to machine with traditional techniques. Electric discharge machining edm to machine difficulttomachine materials and high strength temperature resistant alloys too. The impact of free abrasive particles on the work surface. During this machining process, a small portion of metals is also eroded away, leaving a small cater. These sparks strike the surface of the metal, carving out the shape of the electrode. Edm typically works with materials that are electrically conductive, although methods have also been proposed for using edm to machine insulating ceramics 8 9. 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. Compared with conventional machiningfrom basic cnc turning all the way up to 5axisedm has certain advantages and disadvantages. When the best electrode can be determine, it would lead to better process performance in electric discharge machining edm. Performance study of wire cut electric discharge machining. Similarly, theres typically more than one way to cut parts. Ultrasonic machining usm and waterjet machining wjm are typical examples of single. In electric discharge machining process an arc is produced when two currentcarrying wires are shortcircuited. A thermo electric model of material removal during electric 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. To archive this, the characteristic of machining must be determine because the higher material removal. Wire electrical discharge machining process has been established as a crucial nonconventional thermoelectric machining technique to machine the materials which are a conductor of electricity. Modelling of micro electric discharge machining using fem. Anywhere from 1,000 to 100,000 sparks are generated on and off between the electrode and the metal per second. Electric discharge machining is a process of metal removal from a conducting work piece by a repetitive spark discharge initiated between negative tool and positive work piece separated by a dielectric medium. Surface integrity can be as good as or better than a ground surface 10,11.
Electric discharge machining edm ppt topics for seminar. Edm machining process is also known as spark erosion machining. Paper open access related content analysis of effects of. Small hole edm drilling small hole edm drilling, also known as fast hole edm drilling, hole popper, and start hole edm drilling, uses a guided hollow electrode to drill holes by means of electrical discharge machining by eroding material from the workpiece, as shown in figure 1. Any complicated shapes made on the tool can be reproduced. Electric discharge machining free download as powerpoint presentation. Modern machining unit 5 modern machining method method structure 5. Electrical discharge machining edm is one of the most widely used non traditional. Electric discharge machiningbasic terms and working. Electrical discharge machining edm is one of the earliest and most widely used nonconventional machining processes. Electric discharge machining using relaxation circuit b i. Wire electrical discharge machining edm is a process of metal machining in which a tool discharges thousands of sparks to a metal workpiece.
Electric discharge machining machining electromagnetism. This electric spark produces intense heat with temperatures reaching 8000 to 12000 degrees celsius, melting almost anything. The machining medium is solid grains suspended in an abrasive slurry in the former,while a fluid is employed in the wjm process. P a g e 39 the characteristics of the loss function are 1. Principles of electrical discharge machining and non. Current status and future perspectives for surface modification of biomedical implants. It yields low scrap, almost automatic operation, low overall machining time, and reduced inventory expenses. Edm circuits and working principles with diagram 4. Mar 11, 2016 in electric discharge machining process an arc is produced when two currentcarrying wires are shortcircuited. The basic electrical discharge machining process is really quite simple. Russian scientist lazarenko 1 studied the electric discharge for metal cutting application and developed spark erosion machine in 1943. Other machining processes theres more than one way to skin a cat, as the old expression goes. Here are some advantages of electro discharge machining.
A nonconventional process, wire edm works on parts resistant to conventional machining processes, but only if these parts are electrically conductive. 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. Oct 23, 2008 lecture series on manufacturing processes ii by prof. Feb 26, 2015 references a b theoretical models of the electrical discharge machining process. Good surface finish can be achieved economically up to 0. As shown in the above steps, the tool is normally above the work piece and wired to the positive voltage, the work piece is in distilled water a dielectric fluid a liquid that doesnt. History of edm in1770s, discovered by joseph priestly. Basics of electrical discharge machining the origin of electrical discharge machining goes. Paul,department of mechanical engineering, iit kharagpur. 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. Lecture electric discharge grinding, electric discharge diamond grinding and.
Principle, working, equipments, application, advantages, and disadvantages find, read and cite all the research you need on researchgate. In electro chemical machining an electrolyte acts as a current carrier. Smart material, adaptive structures and intelligent mechanical systems iitk. The electrolyte in ecm should have high electrical conductivity, low viscosity, high specific heat, chemical stability, resistance to form a passivating film on the workpiece surface, noncorrosives and nontoxicity. An electrical spark is created between an electrode and a workpiece. Micro edm having same principle characteristics of conventional edm, but difference is of low specific energy of material removal at low discharge levels, which improves the machining accuracy. Pdf electric machine by ashfaq husain book free download. 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 order to create desired shape. Lecture series on manufacturing processes ii by prof. There is no thermal damage and burr free surface can be produced. Performance study of wire cut electric discharge machining process by using.