The American University in Cairo Laser Applications in Manufacturing

1
The American University in Cairo Laser
Applications in Manufacturing

• MENG 439 Advanced Manufacturing Processes
• Dr. L. Gaafar
• Presented By
• Ahmed Waguih
• Amira Hussein
• Lobna Abdel Azim

Spring 2002
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Outline

• Laser Technology
• Processes
• Cutting
• Drilling
• Welding
• Rapid Prototyping
• Other Precise Measurement, Heat Treatment,
  Scribing
• General Advantages and Disadvantages
• Economics
• Safety measures
• Useful Links and References

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Laser Technology

• Thermal nontraditional machining process
• High energy laser beam melts and vaporizes
  material
• Beam
• Continuous
• Pulse
• Examples of lasing materials
• Co2
• YAG

Outline
see comment
4
Laser Technology

• Beam generation

Schematic diagram of a laser beam machine1
Outline
see comment
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Laser Technology

• Important physical parameters of workpiece
  materials
• Reflectivity
• Thermal conductivity
• Specific heat
• Latent heat
• Features of laser beam
• High power
• Monochromatic
• Coherent
• Non-contact

Outline
see comment
6
Laser Technology

• Beam Delivery Systems
• Hard optic Delivery
• Moving workpiece
• relatively inexpensive
• can accommodate large heavy lasers
• operate quick (20 m/min)
• but heavy large piece limited

Hard optic Delivery3
Outline
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Laser Technology

• Moving laser
• Relatively inexpensive
• Can accommodate large and heavy piece
• But compact laser system required (solution
  optical fiber), but the load of laser is a
  constant, easy to design

Hard optic Delivery3
Outline
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Laser Technology

• Fiber optic Delivery
• quick move (more than 100 m/min)
• 3D structure
• but expensive

Fiber optic delivery3
Outline
see comment
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Processes
Applications of Laser in manufacturing3
Outline
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Processes Cutting

• Cutting starts by drilling a hole then moving the
  beam in a programmed path.
• A stream of assist gas is used to
• blow the molten metal
• Cool workpiece
• Minimize heat affected zone

Laser Processing System3
Outline
see comment
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Processes Cutting

• Cutting Speed depends on
• Material
• Thickness
• Range of thickness
• Metals up to 0.5in
• Nonmetal up to 1in

Outline
see comment
12
Processes Cutting

• Applications

Height following Laser nozzle3
Examples of laser cutting using pulsed CO2 Laser3
Outline
13
Processes Cutting

• Advantages
• Narrow kerf and heat affected zone
• No post-cut finishing is required
• Economic alternative for materials that are
  difficult to cut by conventional methods
• Narrow slots
• Closely spaced patterns
• Does not require smooth surface

Outline
see comment
14
Processes Drilling

• Repeated pulsed laser beams
• Hole diameter depends on the material thickness
• Drill micro-holes in metals as thick as 0.1in
• LD ratio 101
• Cutting Speed decreases? depth increases but
• Generates irregular holes
• Recast layer increases
• Heat affected zone increases

Outline
see comment
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Process Drilling

• Applications
• Bleeder holes for fuel pump covers
• Drilling holes in delicate medical materials
• Drilling holes in small polymer tubes
• Drills tiny holes in turbine blades of jet engine

Outline
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Processes Drilling

• Advantages
• Burr free holes
• Eliminates drill breakage and wear
• Drills in difficult to access areas, curved
  surfaces and parts incased in glass
• Drills holes of almost any shape
• High quality and precision holes
• Close tolerances
• Limitations
• Holes up to 1 deep in plastics and ferrous
  metals, and 0.125 in reflective materials.

Outline
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Processes Welding

• Could be used with or without filler
• Solidifies quickly
• Filler material is used if gap is large
• Can be used to produce deep penetration welds
• Effective with thin workpiece

Outline
see comment
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Processes Welding

• Applications
• Razor blades
• Electronic circuits

Razor blades are spot welded using laser3
Outline
see comment
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Processes Welding

• Advantages
• Does not require vacuum
• Better quality of weld
• Beam easily shaped, directed, and focused
• No direct contact is necessary to produce a weld
• Encapsulated and inaccessible areas can be
  welded
• Can be made with access to only one side of joint
• Increase speed and strength of welding
• Produces maximum penetration and minimum
  distortion in the material

Outline
see comment
20
Processes Rapid Prototyping

• Powder metal is used
• Metal is melt and fused using laser beams
• A physical prototype is built layer by layer
• 3D CAD files are used

Schematic diagram of a rapid prototyping machine6
Outline
see comment
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Processes Rapid Prototyping

• Applications

Models created by rapid prototyping 7
Outline
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Processes Rapid Prototyping

• Advantages
• Speeds up the design and manufacturing process
• Reduces product development cost
• Allows for instant feedback to design engineers
• Allows for design corrections at an early stage
• The model is used in pre-production planning and
  tool design

Outline
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Processes Rapid Prototyping

• Disadvantages
• The generated model has shrinkage cracks
• The model has high hardness, which makes it
  brittle
• Thick walled structures cant be built up very
  well

Outline
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Processes Measurements

• Uses Helium-Neon laser beam
• To align and calibrate machine tools
• Useful in Large assembly jigs
• Non-contact used to inspect hot rolled material

Outline
see comment
25
Processes Heat Treatment

• Produces hardened surfaces
• For wide variety of geometries
• Can work on limited area
• Produces little distortion

Cam Part 14
Outline
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Processes Scribing

• Composed of series of closely placed holes
• To produce lines and characters with different
  fonts on materials
• As wide as laser beam
• Set to a specific tolerance depth

Application of scribing 15
Cut, Scribe and Weld operations 3
Outline
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General Advantages

• Operates in fully automated environment
• Minimum heat affected zone compared to other
  thermal processes
• Clean
• Small clamping force is applied
• Can be used with metals, nonmetals, and
  composites
• Excellent surface quality
• Minimum thermal stresses on the material
• No tooling required

Outline
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General Disadvantages

• Requires specially trained operators
• Not for mass metal removal processes
• Requires greater control of joint tolerances
• Expensive equipment
• Consumes much energy

Outline
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Economics

• Expensive equipment
• Requires skilled operators
• Compensated by
• Fast material removal rate (0.5-7.5m/min) ? high
  production rates
• Finishing costs are eliminated
• Can be automated ? reducing operational costs

Outline
see comment
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Economics

• Comparison between automated and non-automated
  production in good and lean times

Outline
Before and after automation 13
see comment
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Economics

• Cost of Laser Cutting Machine
• New 200,000
• Used starting 30,000
• CNC 750,000

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Safety Measures

• Lasers can burn and blind
• Eyes and skin should be protected from scattered
  beams
• Even low powers can cause damage to retina
• Operator should wear gas masks to protect against
  generated fumes

Outline
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Useful Links

• www. Electro-optics.Org
• Http//www.rpc.msoe.edu/machines_sls.php

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References

• Degarmo,E.P., Black, kohser. Materials and
  Processes in Manufacturing. Printice Hall, UK.
  Eighth ed.,1997.
• Kalpakjian,Serope. Manufacturing Processes for
  Engineering Materials. Addison Wesley. Third ed.,
  1997.
• www. Electro-optics.org
• http//www.laserprototype.com/rapidprototyping.htm
  
• http//www.wa.wb.utwente.nl/Research/lasergen/lgre
  s2.htm
• http//www.rpc.msoe.edu/machines_sls.php
• http//www.denouden.demon.nl/capsel/rapprod2.htm
• http//www.iesl.forth.gr/lic/Drilling.html
• http//www.californialasers.com/laserdrilling/lase
  rdrilling.html
• http//www.laserage.com/drilling.htm
• http//www.precisionlasermfg.com/Laser/laser.php3
• http//www.repairfaq.org/sam/laserfaq.htmfaqilp1
  
• http//www.mazaklaser.com/economics.html
• http//www.alotec.de/laserhardening_left.html
• http//www.lasermachining.com/applications/process
  es/scribing.htm
• http//www.franeklaser.com/usedlasers.htm

Outline