Laser and laser cladding
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This document provides a summary of how lasers are used in various manufacturing applications. It discusses laser welding, cleaning, surface treatments, direct laser fabrication, and selective laser sintering. Laser welding is now commonly used in production and can provide benefits like high speeds, narrow welds with less distortion, and accuracy. Laser cleaning is an emerging process being used for applications like tool restoration and electronics. Surface treatments like hardening, melting, and alloying can improve properties using lasers. Direct laser fabrication and selective laser sintering allow building parts layer-by-layer from powders. Emerging applications also include laser forming of sheet metal and nanostructure generation.
Laser and laser cladding
- 1. Lasers in Manufacturing Present: Erfan Zaker Esfahani Email: aref_z_e@yahoo.com Number: 09131299216 Lecturer: Dr. saebnoori University: najaf abad Number of student: 890914688 Course: Surface Engineering
- 2. Introduction Laser Welding Laser Cleaning Surface treatments Laser Cladding Direct Laser Fabrication Selective Laser Sintering Laser Forming - an emerging process
- 3. Laser Welding Established in the early 80’s Now used on many production lines Low volume applications and subcontract limited to niche areas such as mould tool repair, jewellery and dentistry
- 4. Welding Key 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. Welding A 10 kW fibre laser used in shipbuilding A hybrid laser welding system
- 6. Spot and MicroWelding Repairing mould tools Medical devices 400 m spot welds on a orthodontic bracket Sensors Read / Write heads Orthodontic Bracket
- 7. Other Laser Welding applications Plastics and Polymer Welding Possible to use laser to weld transparent plastic to opaque plastic (n.b. “transparent and “opaque” refer to laser wavelengths) Clear weld® Uses absorbing dye in joint interface to weld two nominally transparent polymers Can even be used for clothing!
- 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 this combination “Remote Welding” Use high beam quality “slab” and fibre lasers coupled to a scanning head to weld at multiple x- y-z positions
- 9. Cleaning Emerging process, particularly driven by art and monument restoration (I.e. National Museums and Galleries on Merseyside (NMGM) conservation centre. Engineering applications are being identified – dry cleaning of metal components prior to welding and PCB’s and component leads prior to soldering.
- 10. Cleaning Advantages 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 easily The operator protection is reduced to a simple eye protection
- 11. Engineering applications of laser cleaning are being developed. Applications include mould tool cleaning Stripping of paint from aircraft Cleaning
- 12. Surface treatments Three main processes – hardening, melting and alloying. Aim to improve surface properties such as wear and corrosion resistance, one can: Temper Laser Hardening Laser fusing / cladding (depositing a hardwearing corrosion resistant surface) Alloying surfaces Nitrate Treat many different materials Laser hardening Laser Alloying
- 13. Surface treatments Special hardening process for titanium Surface is laser heated. Nitrogen is blown over the surface forming titanium nitride under on the surface. The surface hardness is increased many times compared with the parent material.
- 14. Laser Cladding Deposition of wear and corrosion resistant materials. Reduced heat input gives lower distortion.
- 15. Direct Laser Fabrication DLF 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 is traced out layer by layer
- 16. Direct Laser Fabrication General set-up of Direct Metal Deposition
- 17. Direct Laser Fabrication Tool repair Mould repair Turbine blade repair Rapid Prototyping
- 18. Selective Laser Sintering Parts built up layer by layer A CO2 laser beam selectively melts powder into a designated shape The component sinks into the bed, a layer of powder is deposition above the component The process repeats until the component is finished
- 20. Laser Forming - an emerging process Bending metal with light Laser beam induces thermal stresses The plate expands, cools and contracts The flat plate deforms into a new shape Industrial sectors Aerospace Automotive Marine
- 21. Structuring and texturing Periodic Structures (with period <1um) machined into metals and ceramics, and also produced by material modification in polymers
- 22. Direct writing in Fused Silica Pulse duration 100fs, Wavelength 400nm, Pulse energy 0.8μJ Scan speed 200 μm/s 10 μm pitch, 0.5NA
- 23. CW Fibre laser generation of Nanoparticles High intensity laser beams vapourise materials that then condense as sub-micron powders. CW fibre laser combine high intensity with high intensity
- 24. 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 J DTI Funded project “Ultrafast” completed at LLEC – scored 56/60 in final assessment