 Hello friends, I am Mr. Nagesh Arthambake, Assistant Professor, Department of Mechanical Engineering, Vulture Institute of Technology, Sholopur. Today, we will discuss on the topic unconventional machining process. Learning outcome of this particular session each at the end of this session. Students will be able to understand the need of unconventional machining processes. Now in this particular session, we are discussing introduction, classification, significance, advantages and disadvantages. Now before going to the unconventional machining process, now we will recall what is conventional machining process. In conventional machining process, we are using a conventional machines where the tool is directly contacted with the work piece and then machining can be carried out. So there for example, on the lathe machine with the help of tool directly contacted with the work piece, that is we are making the operation such as turning, facing, grooving, knurling, likewise whatever the operations that we are making that are the conventional machining processes. Other than conventional machining processes are milling, then planing, slotting, whatever these machines are there, these are called as the conventional machining process. Now we will see what is unconventional machining process. An unconventional machining process or non-traditional machining process is a special type of machining process in which there is no direct contact between the tool and the work piece. As we have discussed in conventional machining process, there is direct contact but here there is no direct contact between the tool and the work piece. unconventional machining, a form of energy is used to remove unwanted material from a given workpiece. Now we will see the definition, what is mean by unconventional machining process. Unconventional machining process is defined as a group of processes that removes excess stock material from workpiece by various techniques involving mechanical, thermal, electrical and chemical energy or combination of these energies, but do not use a sharp cutting tools as it needs to be used for traditional machining processes. Now we will see the classification of unconventional machining process, first one is mechanical energy based unconventional machining process. Here the medium is abrasive jet machining, abrasive jet machining in this the medium is abrasive. Here we are using a carbide powder as a abrasive, silicon carbide as a abrasive, next one is a water jet machining that is also called as water jet cutting. In this we are using a water pressure, a high water pressure with abrasive we are mixing with the water and then it is forcefully applied on the material, therefore the material is going to cut and machining occurs. Now abrasive water jet machining, it is a combination of first two, now third one is ultrasonic machining, here we are making use of a high pressure ultrasonic tool. Now next one is electrical energy based unconventional machining process, here the medium is electrical current, electrical discharge machining, electrical discharge machining here with the help of current the material is going to machine, the workpiece is going to machine and then wire cut electro discharge machining is there, here the tool is wire is acting like a tool therefore here it is called as wire cut electro electrical discharge machining. Next one electrochemical energy based unconventional machining process, electrochemical machining is there, then electrochemical grinding is there, electrochemical honing is there, three processes that we can make with the help of electrochemical energy. Now fourth one is thermo electrical, here there is a combination of thermal and electrical medium therefore it is called as thermo electrical energy based unconventional machining process. In this we are having plasma arc machining, electron beam machining, laser beam machining and ion beam machining. So out of this we are discussing only four types of unconventional machining process, first one is electro discharge machining, second one is abrasive water jet machining, third one is ultrasonic machining and whatever the last process that we are discussing that is electrochemical machining. Now here what is the significance of unconventional machining that is in several engineering industries, have a rapid growth in the development of harder and difficult to machine materials such as ceramics, carbides, stainless steels, high speed steels, heat resistant steels and many other high strength temperature resistance alloys. These hard to machine materials are found by application in aircraft industry, research equipment, missile technology, nuclear engineering and other industries owing to their high strength to weight ratio hardness and heat resistant qualities therefore the engineers are forced to innovate such type of systems. Now next one is if such materials are machined with the help of conventional machining processes either the tool undergoes extreme wear while machining hard work piece or the work piece material is damaged while machining better work piece. This is because in conventional machining there is a direct contact between the tool and the work piece, large cutting forces are involved and material is removed in the form of chips. A huge amount of heat is produced in the work piece, this induces residual stresses which degrades the life and quality of the work piece material. This conventional machining produces poor quality work piece with poor surface finish if the work piece is made of hard and brittle material. For such materials the conventional aged tool machining in spite of recent technological advancement is highly uneconomical and degree of accuracy and surface finish attainable are poor. Besides machining of these materials into complex shapes is difficult and time consuming sometimes it is impossible. To overcome all these drawbacks we use unconventional machining process to machine hard and brittle material. We also use unconventional machining processes to machine soft materials in order to get better dimensional accuracy. In all we have seen these particular unconventional machining machines are there, these are expensive but here we are getting a more surface finish and whatever the harder materials are there that can be easily machined over here. In conventional machining if we are carrying out the machining of harder material then what will happen? We require more force and due to this force what will happen due to larger force the tool may break. So breakage of tool can occur and that is again more expensive. Therefore unconventional machining process is overcome all those difficulties and those machining materials are not possible with the help of conventional machining process that we are making with the help of unconventional machining process. Now we will see some of the advantages are there, advantages are very important. Now with this particular unconventional machining process we can increase the productivity. Then we will get high accuracy and surface finish, good surface finish that is up to 2 micron. Then close tolerance is possible because as here the workpiece, the gap between the tool and the workpiece is maintained therefore we can get close tolerance over here. Here there is no question of any vibration to the workpiece therefore close tolerance is that we can make. Then no direct contact of tool and workpiece will be there. So there should not be any veering of the tool. Tool material need not be harder than workpiece. Machined surface does not have residual stress as there is no direct contact of the tool with the workpiece therefore machine surface does not have residual stress. Tool life is more as there is no wear definitely the tool life will be more. Now some of the limitations or disadvantages are there, material removal rate is slow why because very small material can be removed. Now whatever the abrasive jet machining is there, plasma arc machining is there and electron beam machining is there are not commercially economical process. These are very expensive process. Now this particular whatever the cost of the equipment is there that is very high. Complex setup is there. Now here definitely skilled operators are required and these are the references. I will recommend two books, Workshop Technology by Raghun Mushi, Production Technology by PC Sharma that is HMT Handbook. Thank you.