Welding p

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Welding p

  1. 1. MANUFACTURING PROCESSES IPRESENTATION NAMEDIFFERENT TYPES OF WELDING
  2. 2. WELDINGWelding is a process in which two or moreparts of same or different material arejoined together with the help of heat orpressure is known as welding. The jointformed is known as welded joint.
  3. 3. TYPES OF WELDING
  4. 4. THERMITE WELDINGThermite welding is an exothermic welding processthat uses thermite to melt metal, which is pouredbetween two workpieces to form a welded joint.
  5. 5. REACTION The aluminium reduces the oxide of another metal, mostcommonly iron oxide, because aluminium is highly reactive.The maximum reachable temperature is 3090 0C. Theproducts are aluminium oxide, free elemental iron, and alarge amount of heat. The reaction is used for thermitewelding, often used to join rail tracks. Fe2O3 + 2Al → 2Fe + Al2O3
  6. 6. TEMPERATURE VARIATIONThe reaction of the Thermite-welding is started at about 1200 0Cusing a special ignition powder. Themaximum reachable temperature is3090 0C that has to be reducedquickly to about 2480 0C by theaddition of non reacting pellets offerroalloy.
  7. 7. SLAGAt 2500 0C the aluminumwould vaporize. The aluminumslag (Al2O3), that has to remainliquid to float and separatefrom the metal, would solidifyat 2040 0C (3700 0F) and less.
  8. 8. LABLED DIAGRAM
  9. 9. APPLICATION•Thermite welding is mainly used in repair andwelding of large forgings and castings, pipes, millhousings and heavy rail sections.•Applications are used to repair heavy sections•Often used to join rail tracks•Field welding of track
  10. 10. ELECTRON BEAM WELDING Electron Beam Welding (EBW) is a fusion joining process that produces a weld by impinging a beam of high energy electrons to heat the weld joint. (EBW) is done in vacuum.
  11. 11. PROCESSAn EBW gun functions similarly to a TV picturetube. The major difference is that a TV picturetube continuously scans the surface of aluminescent screen using a low intensityelectron beam to produce a picture. An EBWgun uses a high intensity electron beam totarget a weld joint. The weld joint converts theelectron beam to the heat input required tomake a fusion weld.
  12. 12. EQUIPMENTS• Electron gun, generating the electron beam• Working chamber, mostly evacuated to "low" or "high" vacuum• Work-piece manipulator (positioning mechanism)• Supply and control/monitoring electronics
  13. 13. FUNCTIONThe electron beam is alwaysgenerated in a high Although, highvacuum welding will provide maximumpurity and high depth to width ratiowelds.
  14. 14. LABLED DIAGRAM
  15. 15. SOLID STATE WELDINGSolid State Welding is a welding process, inwhich two work pieces are joined under apressure providing an intimate contactbetween them and at a temperatureessentially below the melting point of theparent material.
  16. 16. TYPES OF SOLID STATE WELDING COLD PRESSURE WELDING ULTRA SONIC WELDING
  17. 17. COLD WELDINGCold or contact welding isa solid state welding process inwhich joining takes placewithout fusion/heating at theinterface of the two parts to bewelded. Unlike in the fusion-welding processes, no liquid ormolten phase is present in thejoint.
  18. 18. PRINCIPLECold welding is a method for joining non-ferrousmetals and their alloys without using heat, fillers orfluxes. Round wire sections, dissimilar materials andmaterials of different sizes can all be welded withBWEs proven cold welding technology. A cold weld isgenerally stronger than the parent material and hasthe same electrical characteristics.
  19. 19. DIES IN COLD WELDINGThe dies play an important role inthe cold weld process. Firstly, theymust grip the material firmlyand, therefore, the inside of thecavity is either etched with anelectric pencil or, when the die is tobe used for welding large pieces ofaluminium, grip marks are put in thecavity before the die is heat treated.
  20. 20. CHARACTERISTICS OF COLD WELDING • At least one of the metals must be ductile without excessive work-hardening • Total absence of applied heating • Dissimilar metals can be joined • Surface preparation is important
  21. 21. COLD WELDING PROCESS DESCRIPTION• The parts to be welded are first cleaned.• A short section of the part is sheared• The parts are clamped in a die with some initial extension• A forging force is applied to complete welding.
  22. 22. STAGES OF COLD WELDING
  23. 23. COLD WELDING EQUIPMENTMANUALLY OPERATEDCOLD WELDING MACHINE
  24. 24. COLD WELDED PART DIAGRAM
  25. 25. APPLICATION• Cold welded butt joints are used in themanufacturingof aluminum, copper, gold, silver, and platinumwire• Most commonly, successive reels of wireare joined for continuous drawing to a smallerdiameter• Aluminum alloys used in cold welding
  26. 26. ULTRASONIC WELDINGUltrasonic welding is an industrial technique wherebyhigh-frequency ultrasonic acoustic vibrations arelocally applied to work pieces being held togetherunder pressure to create a solid-state weld.
  27. 27. Why to use US welding?• First - Ultrasonic assembly uses ultrasonic vibratory energy which is transmitted through the parts to melt and bond thermoplastic materials And joining thin sheet gauge metals and other lightweight materials Second - This technique is fast, efficient, non- contaminating and requires no consumables. Third - In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together.
  28. 28. PRINCIPLE In ultrasonic welding, frictional heat producedby the ultrasonic waves and force is used for thejoining process. Ultrasonic waves (15 to 60 kHz)are transferred to the material under pressurewith a sonometer. Welding times are lower than3 s. The welding can proceed with or withoutthe application of external heat.
  29. 29. ADVANTAGES• Heat affected zone is minimized• Very thin materials can be welded• Surface deformation is minimum• Welding of glass is also possible• No defects due to gases, arc and filler metal• Equipment is simple and moderate skill is enough• Dissimilar materials can be joined
  30. 30. DISADVANTAGES• Restricted to join thin materials• Competitively not economical• Materials being welded may tend to weld to the tip and anvil
  31. 31. Application• Manufacturing of toys• Joining of electrical and electronic components• Welding aluminium wire and sheet• Mobiles, sports shoes , laminations, cars etc• Packing , medical industries, computers.
  32. 32. MANUFACTURING PROCESSES IPRESENTATION NAMEDIFFERENT TYPES OF WELDING
  33. 33. PRESENTATION NAME

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