Recommended
More Related Content
What's hot
What's hot (20)
Similar to Introduction to Plasma Arc Machining: Processes, Equipment & Applications
Similar to Introduction to Plasma Arc Machining: Processes, Equipment & Applications (20)
Recently uploaded
Recently uploaded (20)
Introduction to Plasma Arc Machining: Processes, Equipment & Applications
- 1. INTRODUCTION TO PLASMA ARC MACHINING DEPARTMENT OF MECHANICAL ENGINEERING ATRIA INSTITUTE OFTECHNOLOGY ANANDNAGAR, BANGALORE By Team Member's 1. Santhosh Kumar. {1AT19ME410} {1AT19ME411} {1AT19ME412} 2. Subramani.S 3. Sunil Kumar. 4. Vijay.S {1AT19ME413} Course Coordinator: Anjan Kumar, Assistant Professor Dept of Mechanical Engineering Atria Institute Of Technology
- 2. Content in Presentation Introduction Need for PAM Parts of PAM Explanation Of PAMParts Construction Of PAM Working of PAM Applications Advantages Disadavantage Youtube links
- 3. Introduction of Plasma Arc Machining Plasma arc welding is an arc welding process similar to gas tungsten arc welding. The electric arc is formed between an electrode and the workpiece. The key difference from GTAW is that in PAW, the electrode is positioned within the body of the torch, so the plasma arc is separated from the shielding gas envelope It can also be called as Plasma Arc Machining or Plasma Arc Cutting is a thermal machining process which is used to cut the thick workpiece or thick section of electrically conductive Material. The principal of the process is based on utilizing a high temperature plasma, which will be generated by heating gases to elevated temperature (upto a few thousand degrees). The plasma in this state is composed of positive ions, neutral atoms, and free electrons and they disassociated with the main gasatoms.
- 4. A Detailed pic Plasma ArcMachining
- 5. Need for PAM Drilling, sawing, machining, punching or cutting thick metals is very difficult by traditional machining process. Plasma arc cutting is used in place of traditional machining methods, since it can be used to cut a wide variety of metals of varying thickness at high speed. It provides the greatest economical advantages, speed and quality on carbon steels, aluminium, stainless steels etc., when compared to traditional machining methods.
- 6. The video show the plasma Arc Machine Works
- 7. Plasma Arc Machining Equipment's d Plasma Gun: Different gases like nitrogen, hydrogen, argon or mixture of these gases are used to create plasma. This plasma gun has a chamber which has atungsten electrode. This tungsten electrode is connected to the negative terminalan nozzle of the plasma gun is connected to the positive terminal of the DC power supply. The required mixture of gas is supplied to the gun. A strong arc is produced between the anode and the cathode. After that, there is a collision between the electron of the arcand the molecules of the gas and due to this collision, gas moleculesget ionized and heat is generated
- 8. Power Supply: DC Power Supply is used to develop two terminals in the plasma gun. Heavy potential difference is applied across cathode and anode so that arc produced is strong and is able to ionize the gas mixture and convert it intoplasma. Cooling Mechanism: A cooling mechanism is added to the plasma gun as heat is produced in itas hot gases continuously pass out from the nozzle. A water jacket is used to cool the nozzle. The nozzle is surrounded by water jet. Workpiece Different materials can be worked using this plasma arc machining. Different metals like aluminum, magnesium, carbon, stainless steel and alloy steels can be worked using this process.
- 9. Construction Plasma Arc Machining The plasma arc cutting torch carries a tungsten electrode fitted in the chamber. This tungsten electrode is connected to the negative terminal of the DC power supply. For plasma arc machining, a plasma gun is required. This plasma gun has a chamber. This plasma gun has a tungsten electrode fitted inside the chamber. This tungsten electrode is connected to the negative terminal of DC Power Supply and acts as a cathode. At the bottom of the chamber, there is a copper nozzle that is connected to a positive terminal of the DC Power Supply and acts as an anode. The rest of the chamber is made of insulating material and acts as an insulator. Gas enters the chamber through a small passage present at the right side of the chamber. The cathode and the anode remain cool despite the hot gases passing through them as they are water cooled. Water circulation is present around the torch.
- 10. Working of PAM At first, when a D.C power is supplied to the circuit, a strong arc isproduced between the cathode ( electrode ) and the anode (nozzle). After that, gas is supplied to the chamber. This gas can be hydrogen, nitrogen, argon or mixture of these gases chosen according to the metal to be worked. The gas used in the process is heated using the arc produced between the cathode and the anode. This gas is heated to very high temperatures from 11000 °C to 28000°C. As the arc comes into contact with the gas, there is a collision between the electron of the arc and the molecules of the gas and the molecules of thegas will dissociate into separateatoms. Due to the high high temperature generated from the arc, electrons from some atoms will be displaced and atoms are ionized ( electrically charged) and the gas turns into plasma. As the gas is ionized, a large amount of thermal energy is liberated.
- 11. Working of PAM After the gas is ionized, this high temperature ionized gas is directed towards the workpiece with high velocity. The electric arc has some other benefits like it increases the temperature of ionized gas, makes the beam almost parallel, and increases the velocity of the gas. As the plasma jet reaches the workpiece, the plasma melts the workpiece and the high-velocity gas blows away the moltenmetal. In this way, plasm arc machining is used to remove material fromthe workpiece.
- 12. Mechanism of Metal Removal Is a basically due to the high temperture produced in the workpiece material. The heating phenomenon that takes place at the workpiece is a combination of anode heating, due to direct electrons bombardment, and convection heating from the high temperture plasma that accompaines the arc. The resulting heat is sufficent to raise the temperture of the workpiece material above the melting point, and the flowing high velocity gas stream effictively blows the molten metal away resulting in metal removal to take place.
- 13. Modes of Operations of Plasma Torch There are two types of modes of operations of plasma torch 1. Transferred arcmode 2. Non-Transferred arcmode A benefit of transferred DC torches is that the plasma arc is formed outside the water-cooled body, preventing heat loss—as is the case with non-transferred torches, where their electrical-to-thermal efficiency can be as low as 50%, but the hot water can itself be utilized.[6] Furthermore, transferred DC torches can be used in a twin-torch setup, where one torch is cathodic and the other anodic, Which has the earlier benefit of a regular transferred single-torch system, but allows their use with non-conductive materials, as there is no need for it to form the other electrode.[5] However, these types of setups are rare as most common non- conductive materials do not require the precise cutting ability of A plasma torch. In addition, the discharge generated by this particular plasma source configuration is characterized by a complex shape and fluid dynamics that requires a 3D description in order to be predicted, making performance unsteady. The electrodes of non-transferred torches are larger, because they suffer more wear by the plasma arc.
- 14. Applications of PAM It is used in mill applications. It is also used in the nuclear submarine pipe system. Used in welding rocket motor case. Used in welding of stainless steel tubes. It is used for profile cutting.
- 15. Advantages of PAM Hard as well as brittle metals can be easily machined with this process. Plasma Arc Machining gives a faster production rate. Small cavities can be machined using this process with good dimensional accuracy. It can be used for rough turning of very hard materials. It can be used for rough turning of very hard materials. It is also used in machines that are used to repair jet engine blades.
- 16. Disadvantages of PAM The equipment used in Plasma Arc Machining are very costly. Metallurgical changes take place on the surface of the workpiece. The consumption of inert gas is high. As oxidation and scale formation takes place, shielding is required.