Laser and laser cladding

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Laser and laser cladding

  1. 1. Lasers inManufacturingPresent: Erfan Zaker EsfahaniEmail: aref_z_e@yahoo.comNumber: 09131299216Lecturer: Dr. saebnooriUniversity: najaf abadNumber of student: 890914688Course: Surface Engineering
  2. 2. Introduction Laser Welding Laser Cleaning Surface treatments Laser Cladding Direct Laser Fabrication Selective Laser Sintering Laser Forming - an emerging process
  3. 3. Laser Welding Established in the early 80’s Now used on many production lines Low volume applications andsubcontract limited to niche areas suchas mould tool repair, jewellery anddentistry
  4. 4. WeldingKey features of deep penetration laser welding include: High energy density – Keyhole welding Less distortion High processing speeds High throughput Rapid start / stop Unlike arc processes Welds at atmospheric pressures Unlike EB welding No filler required But good fit up is essential Narrow welds Less distortion Very accurate welding possible Good fit up & fixturing needed Good weld bead profiles No beam wander in magnetic fields Unlike EB Little or no contamination Depending on gas shroud
  5. 5. WeldingA 10 kW fibre laser used inshipbuildingA hybrid laser welding system
  6. 6. Spot and MicroWelding Repairing mould tools Medical devices400 m spot welds on aorthodontic bracketSensors Read / Write headsOrthodontic Bracket
  7. 7. Other Laser Welding applicationsPlastics and Polymer WeldingPossible to use laser to weld transparent plastic toopaque plastic (n.b. “transparent and “opaque”refer to laser wavelengths)Clear weld®Uses absorbing dye in joint interface to weld twonominally transparent polymersCan even be used for clothing!
  8. 8. Laser Welding DevelopmentsHybrid WeldingUses combination of arc and laser processesMore tolerant to poor fit upFiller metals can positively modify weld metalOver performance better than expected for thiscombination“Remote Welding”Use high beam quality “slab” and fibre laserscoupled to a scanning head to weld at multiple x-y-z positions
  9. 9. CleaningEmerging process, particularly driven by art andmonument restoration (I.e. National Museums andGalleries on Merseyside (NMGM) conservation centre.Engineering applications are being identified – drycleaning of metal components prior to welding andPCB’s and component leads prior to soldering.
  10. 10. CleaningAdvantages of laser cleaning Laser Cleaning does not damage No abrasive effect (No abrasive) No mechanical contact No heat effect Laser cleaning does not pollute No solvents No polluted effluents Fumes extracted easilyThe operator protection is reduced to a simple eye protection
  11. 11.  Engineering applications of laser cleaningare being developed. Applications include mould tool cleaningStripping of paint from aircraftCleaning
  12. 12. Surface treatments Three main processes –hardening, melting and alloying.Aim to improve surface propertiessuch as wear and corrosionresistance, one can: Temper Laser Hardening Laser fusing / cladding(depositing a hardwearingcorrosion resistant surface) Alloying surfaces Nitrate Treat many different materialsLaser hardeningLaser Alloying
  13. 13. Surface treatmentsSpecial hardening process for titanium Surface is laser heated. Nitrogen is blown over the surface formingtitanium nitride under on the surface. The surface hardness is increased many timescompared with the parent material.
  14. 14. Laser CladdingDeposition of wear and corrosion resistantmaterials.Reduced heat input gives lower distortion.
  15. 15. Direct Laser FabricationDLF combines 4 common technologies CAD CAM Powder Metallurgy Laser Technology A high powered laser creates a melt pool Powder is deposited into the melt pool Moving the laser beam in a prescribed pattern a component istraced out layer by layer
  16. 16. Direct Laser FabricationGeneral set-up of Direct Metal Deposition
  17. 17. Direct Laser Fabrication Tool repair Mould repair Turbine blade repair Rapid Prototyping
  18. 18. Selective Laser Sintering Parts built up layer by layer A CO2 laser beam selectively melts powder into a designatedshape The component sinks into the bed, a layer of powder isdeposition above the component The process repeats until the component is finished
  19. 19. Laser Forming - an emergingprocess Bending metal with light Laser beam induces thermal stresses The plate expands, cools andcontracts The flat plate deforms into a newshapeIndustrial sectors Aerospace Automotive Marine
  20. 20. Structuring and texturing Periodic Structures (with period <1um) machined into metalsand ceramics, and also produced by material modification inpolymers
  21. 21. Direct writing in FusedSilicaPulse duration 100fs,Wavelength 400nm,Pulse energy 0.8μJScan speed 200 μm/s10 μm pitch, 0.5NA
  22. 22. CW Fibre laser generationof NanoparticlesHigh intensity laser beams vapourise materialsthat then condense as sub-micron powders.CW fibre laser combine high intensity with highintensity
  23. 23. pS fibre lasers Fianium laser system: Pulse Length 20ps. Wavelength 1064 nm. Rep Rate 200kHz or 500kHz Maximum Pulse Energy 6 J Laser Power 2.1W Experimental Spot Size 26 JDTI Funded project “Ultrafast” completed at LLEC – scored 56/60 in final assessment
  24. 24. Tanks for attention

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