Industrial Applications of

LASERS

Dr. BC ChoudharyProfessor

NITTTR, Sector-26, Chandigarh-160019

CONTENT OUTLINES

Lasers in Mechanical Industry

Lasers in Electronic Industry

Lasers in Chemical Processes

Lasers in Nuclear Technology

LASER PROCESSING OF MATERIALS

Laser Finishing

Laser Marking

Laser Milling

Laser Striping

Laser Cutting

Laser Drilling

Laser Welding

Laser Etching

Laser Engraving

Laser Machining

Laser Sweeping

Laser Cleaning

Laser Carving

Laser Cooling

Laser Heating

Laser Sealing

Most Important and Fundamental job in Industry.

FUNDAMENTAL REQUIREMENTS

Mechanical Processing on both Metals and Non metals.

Processes require transfer of energy from the laser beam

to the work piece.

• Happens only if the material has high absorption at the wavelength

corresponding to the laser beam.

• Once the surface of the materials absorbs energy, the material starts

to melt and then vapourize.

• At high intensity of radiation, the vapour will be ionized to produce

plasma.

• Plasma layer formed between the laser and the work piece prevents

the laser beam from reaching the work piece.

Essential that plasma should be removed to increase energy

coupling.

Material working requires

large amounts of energy to

be localized at specific areas

in order to cause heating

there Focused beam

Energy Absorption during Mechanical Processing

• Laser should deliver large amount of

power

• Intensity of laser beam can be enhanced

with a suitable optical system that can

focus the beam into a spot of about 10 to

100 m diameter.

Lasers widely used in material processing are CO2 laser

and Nd:YAG laser.

CO2 lasers operate at 10.6 m and metals have high reflectivity

at this wavelength.

Instead of cw CO2 laser, a pulsed mode CO2 laser produces

high peak powers and makes possible to work on metals.

CO2 lasers are cheaper compared to Nd:YAG lasers

CO2 lasers are more generally preferred.

Nd:YAG lasers operate at 1.06 m where metals are less reflective

and are better candidates for working on metals.

Nd:YAG lasers offer the advantage of compactness.

Different materials and working processes require laser

power outputs of different magnitudes.

• For example, relatively low peak power pulses of 10-3 to 10-2 s

width are suitable for welding while more intense and short

pulses of 10-4 to 10-3 s are required for drilling.

LASER CUTTINGLASER WELDING LASER DRILLING

Laser Cutting

A wide range of materials can be cut by CO2 lasers.

Paper, wood, cloth, glass, quartz, ceramics, composites, steel etc.

Cutting process essentially consists of removing material.

Laser cutting is done with the

assistance of air, oxygen or dry

nitrogen gas jet.

The role of the jet is to cool the

surface of the material and blow

away the debris from the cutting

zone.An arrangement for a

gas-laser cutter.

Advantages

Laser cutting is fine and precise.

Introduces a minimum mechanical distortion and thermal shocks

in the material being cut.

The process does not introduce any contamination.

Easily automatised and high production rates can be achieved.

Power Requirements

Power required for cutting depends on the material

Plywood can be cut with a 8 kW CO2 laser while metals can be cut

with 100 to 500W output power of CO2 laser.

Glass-1cm thick requires 20kW output power

Brittle materials such as ceramics and glasses are cut using Pulsed

lasers in order to minimize micro cracking.

In metal cutting, the laser beam heats the metal to a high

temperature where it burns as oxygen passes over it.

• It is therefore actually the oxygen that does the job.

CO2 lasers are used for selective removal of insulation

from electrical wires and cables.

While insulation is stripped off,

the electrical wire inside is not

affected because of its high

reflectivity.

LASER CUTTING SYSTEMS

LASER CUTTING ( 5 m)

LASER CUTTING IN PROCESS

LASER CUTTING OF COMPONENTS

LASER SHEET CUTTING

LASER CUTTING (CORONARY STENT)

LASER CLOTH CUTTING

LASER Drilling

Drilling holes by a laser beam is based on the intense

evaporation of material heated by a series of

powerful light pulses of short duration 10-4 to 10-6 s.

Energy supplied for drilling should be such that

rapid evaporation of material takes place before

radial distribution of heat into the work piece occurs.

Use of a series of short pulses minimizes the energy

diffused laterally into the work piece and assists in

controlling the size and shape of the hole.

CO2 laser and Nd:YAG laser are used widely

• Nd:YAG laser wavelength is used for drilling holes in

metals only

• CO2 laser is equally suitable for drilling in metallic and

non-metallic materials.

Laser drilling is a non-contact process and does not require

a physical drill bit.

Problems of wear and broken drill do not arise.

Process becomes faster and also highly reproducible.

Drilling operation can be done with extremely high

precision and in any desired direction.

Lasers have advantage where high speeds and small

holes in deformable materials are required:

• Perforation in plastics, nozzles and nylon buttons

• Three holes: one at the top for the liquid and the

other two for air inlets.

• The rubber used for nipples is very soft and flexible.

• Earlier holes were made in nipples mechanically with

fine wire pins but the rubber bends and pins can be

caught and broken by the rubber

An Interesting Example: Piercing of holes in a baby bottle nipple

With laser beams, tiny holes are burnt through the

rubber. Using beam splitters laser output is split into

three beams and the job is done in a fast and efficient

manner.

Drilling holes in Diamond Dies:

For making thin metal wires, usually the metal is pulled through tiny

holes in diamond “dies”.

However, diamond is very hard material and it is difficult to drill

holes in it. Normally, diamond drill bits are used to drill and these

drill bits get dull as they drill

Holes can be made very easily through diamond by a laser beam

focused to a tiny spot.

Drilling in Ceramic Materials: Lasers are routinely used for

drilling in ceramic materials

• Ceramic materials become brittle after they are burnt and therefore

conventional drilling has to be performed prior to firing. The size and

position of the hole may change after firing.

• Laser drilling is carried out after firing and therefore, size variation

does not take place.

LASER DRILLIED SPICIMEN

LASER DRILLED HOLES LASER DRILLED MICRO HOLES

DEPTH CONTROL BY UV LASER

LASER TAPER (+ve/-ve) DRILLING (125

MICRON DIAMETER, ALUMINA)

Laser Welding

Welding is the joining of two or more pieces

into a single unit.

Metal pieces are held in contact

at their edges and a laser beam

is made to move along the line

of contact of the plates.

The laser beam heats the edges

of the two plates to their

melting points and cause them

to fuse together where they are

in contact.

MECHANISM OF LASER WELDING

Inert gas laser welding for inaccessible

locations.

Laser welding can be done

even at difficult to reach

places.

Heat affected zone is relatively small because of rapid cooling.

The process is easily automated.

Laser welding is a contact less process No possibility of

introduction of impurities into the joint.

Unlike electron beam welding, it can be done in atmosphere.

The work pieces do not get distorted total amount of power

input is very small compared to conventional welding processes.

Main Advantages

Most common laser used in Welding is the CO2 laser

(Both CW and Pulsed form).

Gases such as He, Ar and N2 are often used with laser

welding for protection against oxidation of metal surfaces.

In pulsed laser welding Nd:YAG and Nd:glass lasers of

low repetition rates are generally used.

A CO2 laser can also weld sheets or films of plastic

materials.

Laser welding shot.wmv

Typical example of laser welding is the welding of urved contours

under body of automobiles. The automobile is made to move

while computer-controlled beam deflectors control the laser beam

which performs the welding.

Automobile Welding -Robotics

LASER Welding of an Interface

LASER Welding of Delivery Tubes

LASER Weld Inner Door Panel Made Up

of Different Steels

LASER Plastic Welding

LASER Welding of Dissimilar

metals (Cu-Ni)

LASER Welding of Porous

Magnesium

LASER WELD ASSEMBLIES

Heat Treatment

A process which consists of heating metals and certain

other materials for sometime to harden them.

Heat treatment converts the surface layer to a crystalline

state that is harder and more resistant to wear.

In general CO2 lasers of about 1kW output power

operating in CW mode are used for heat treatment.

Metals are more reflecting at 10.6 m, an absorptive

coating such as graphite or Zinc phosphate is

applied on the surface of the work piece to help it

absorb the laser energy more efficiently.

Laser heat treatment requires a low amount of energy

input to the work piece.

Laser processing is advantageous as it can provide

selective treatment of the desirable areas.

Heat treatment is used to strengthen cylinder blocks,

gears, camshafts etc. in the automobile industry.

LASER HARDENING LASER ANNEALING

LASER CLADING: Microstructure

from Ni laser surface alloyed with Al.

The dendrites are of inter-metallic Ni3Al

phase that contribute to the high

hardness of the surface layer

LASER STRIPPING

LASER Marking, Engraving, and Etching

Laser marking is used to induce a permanent alteration

to the surface of a material that is capable of resisting

solvents and abrasion.

Laser marking has numerous advantages over alternative

technologies including:

• High degree of permanence

• Clean & Fast

• Programmable (computer controlled)

• Low consumable costs

LASER MARKING, Engraving, and Etching

LASER Micro-Machining (MEMS)

Micro-machining is to ablate or machine small amounts

of material from the surface of a sample.

Short, intense pulses of UV light from UV lasers are

used for such purposes.

The technique is used for

machining of fine, micron-sized

features in polymer materials,

for micro-hole drilling, selective

thin-film removal, surface

engineering and milling for 3-D

micro-structuring.Holes drilled in a plastic part with

an Excimer laser

LASER Micromachining Workstation

LASER MICRO MACHINING

(Ceramics, Metallic

and Organic Materials)

30 micron diameter holes drilled in

medical device polymer tubing using

a DPSS laser.

LASER Materials Processing in

Nanotechnology

Nanoparticles, Nanomaterials and Nanostructures - Building

blocks of Nanotechnology

Advanced laser-based techniques developed to fabricate

nanostructures on polymer surfaces; succeeded in producing periodic

features < 200 nm in width.

A Top-down formalism

Cellular response is modified in the

presence of the nanostructures.

Ability to fabricate these structures could

also have an important impact on a wide

range of electronic and photonic devices.

Particularly true in the case of materials

that are not easily processed through

photolithographyPeriodic

nanostructures on

polymer surface

Laser induced “Nanojets”

• Nanojets: Self-organised structures of the order of 200 nm

in diameter that are generated through the interaction of

ultrafast (femtosecond) laser pulses with thin metallic

materials coatings.

Computer simulation of laser-generated

nanojet in 20 nm Ni film on silica. The

coloured areas represent regions of

different crystalline phase.

• Structures are important in the

creation of raised nanoscale

features for biotech applications.

• Also, important in the formation of

novel low dimensional structures in

ICT and in the fabrication and rapid

prototyping of plasmonic devices.

Methods for producing “sub-nanolitre droplets” of

liquid drug formulations are being investigated.

Laser techniques are being used to drill specially shaped micro-

holes in a thin membrane, which will be used to generate a

monodisperse cloud of the droplets for pulmonary drug delivery

applications.

In parallel with the fabrication activities, expertise and

instrumentation is being developed for analysing

materials on the nanoscale.

• Research is underway to build an instrument capable of highly

resolved, near-field optical studies of samples

• Techniques are also being developed to resolve the chemical

nature of the surface.

Future technology intentions are to develop techniques

for machining of features < 50 nm.

“Cold” Laser-Ablative Nanoparticle Generation: An

important technique going forward.

Mentioned are some of the immediate interests in

development of nanotechnology. However, it is not

an exhaustive list of ways in which lasers can and

will make an impact in the field.

• In this technique the ability to control the temporal characteristics of

the output on the femtosecond scale – a property unique to lasers –

will facilitate completely non-thermal ablation of materials with

subsequent agglomeration into nanoparticles from the vapour phase.

• Of great importance to the generation of nanoparticles of thermally

sensitive compounds such as drugs.

LASER Processing of

Electronic Material

Processing Electronic Materials

Laser Soldering

Laser Drilling

Laser Scribing

Laser CD Cutting

Laser PCB Cutting

Laser Bar Coding

Laser Marking- Data Matrix

Laser Marking IC Chips

Photolithography

• CO2 lasers for metallic

material processing : Scribing

• ND:YAG for non-metallic

materials : Soldering,

Trimming

• Pulsed Excimer lasers

for finer features:Photolithography

Bar Coding by LASER

CD Cutting by LASER

LASER Marking- Data Matrix

LASER Marking- IC Chips

PCB CUTTING BY CO2 LASER

PCB Marking by LASER

SEMICONDUCTOR DIODE LASER

Multi - Stripe Diode LASER

Visible LASER Diodes

Diode LASER Mounting

LASERS Designs : High-density Printed Board

Sequential layer

construction

Sequential build-up layers

Double layer connection

Multiple layer connection

Four layer connection

Triple layer connection

HDI PWBs and Semiconductor packages used

in Cellular phones and Computers

LASERS Processing of

Chemical Materials

LASER CHEMICAL CHARACTERIZATION

LASER SPECTROSCOPIC CHEMISTRY

LASER CHEMICAL PROCESSING

LASER MICRO-MANIPULATION

LASER CHEMICAL REACTION

CHEMICAL PROCESSING USING LASERS

CHEMICAL CHARACTERIZATION

Determination of Contact Angle

Determination of Concentration

Determination of Surface Tension

Determination of Specific Gravity

Determination of Flash/ Fire Points

Determination of Molecular Weight

Determination of Viscosity/ Fluidity

Molecular (Species) Identification

Super Continuum Generation

Using LASER

DETERMINATION OF CONTACT ANGLE

BY EXCIMER LASER

(HYDROPHILIC SURFACE) (HYDROPHOBIC SURFACE)

Lasers have the ability to selectively alter the bio-response

of a surface

A feature very important for future medical devices and

applications in Nanotechnology

Tubulence Interaction Using

LASER Imaging Technique

Tubulent Reaction Flow Imaging

Using LASER

Decontamination Number~radioactivity

LASER Decontamination

CHEMICAL REACTIONS USING LASER

LASER FLASH PHOTOLYSIS

LASER CHEMICAL AMPLIFICATION

LASER FLASH CHEMICAL REACTION

LASER INDUCED CHEMICAL REACTION

LASER STUDY OF CHEMICAL REACTION

LASER CONTROL OF CHEMICAL REACTION

LASER DRIVEN CHEMICAL REACTION

LASER EXCITED CHEMICAL REACTION

LASER SIMULATION OF SUPERCONTINUUM GENERATION

LASER WAVE ELECTRONIC STEERING (CHEMICAL BOND)

CHEMICAL PROCESSING

CATALYTIC ACTION

CHEMICAL COATING

ISOTOPE SEPARATION

CHEMICAL DEPOSITION

INTERMEDIATE REFINING

CHEMICAL PROCESSING LASER

LASER SPECTROSCOPIC CHEMISTRY

LASER DESORPTION/ IONIZATION MASS SPECTROMETRY

MOLECULAR IDENTIFICATION BY LASER SPECTROSCOPY

LASER SCANNING CONFOCAL MICROSCOPY IMAGING

* * * * *

Processing Materials for

Nuclear Energy

Fusion and Fission Reactions

• Efficient sources of energy

• Form the basis for generation of electricity from

nuclear based technology.

Electricity from Nuclear Fission

Nuclear power plants account ~17 percent

of the worlds power.

Isotope Separation

Natural uranium contains only 0.7% of U235.

To be useful for nuclear power generation or for production of

nuclear weapons Essential is about 3% of U235 be present.

In Nuclear Power Plants, Natural Uranium is used to fuel the

fission reactor.

• Natural uranium ore mainly contain two principal isotopes

U238 and U235

• U238 is the more abundant isotope but it cannot sustain the

fission chain reaction needed to drive the nuclear reactor.

• It is U235 isotope that sustains a fission reaction.

Isotope enrichment of Uranium is a very important problem

and in general this enrichment is performed using gaseous

diffusion Processes.

Very expensive and time consuming.

Isotopes are chemically almost identical

• Differences in the nuclear mass shift the electronic energy

levels slightly and therefore each isotope absorbs light at

different characteristic wavelength.

• Absorption bands are fairly narrow and lie close to each

other.

• If the mixture of isotopes is irradiated by a source of narrow

bandwidth, it is possible to excite one isotope without

disturbing the other.

Selectively excited U235 atoms can be

ionized by applying another short

wavelength light to the mixture.

Ionized U235 atoms can be separated

from the neutral U238 atoms using

electrostatic fields.

Schematic of Uranium isotope

separation facility

Lasers have very narrow bandwidth and can be helpful in

this process.

Desired energy can be obtained by tuning a Dye laser to a precise

wavelength with a very narrow linewidth.

Atomic vapor laser isotope

separation (AVLIS) process

for Uranium enrichment,

(Livermore, USA)

Green light is converted to

red–orange light of three

different wavelengths that

are absorbed only by

Uranium-235.

Laser Isotope Separation

NUCLEAR FUSION

The Phenomenon of Fission is a good source of

nuclear energy. A considerable larger amount of

energy can, however, be obtained by fusion of light

elements in heavier ones.

The energy yield per gram in fusion 8 times that in the

fission.

To effect the fusion of two or more nuclei, they must be

brought so close together against the force of electrostatic

repulsion that they face within the range of nuclear forces.

This will occur only if the interacting nuclei have K.E. of

about 0.1 MeV or more.

• To produce fusion of large mass of material, K.E. must be

due to the thermal motion of the nuclei, could in principle

result from a sufficient increase in temperature.

• To impart the particles energies as high as 0.1 MeV, its

temperature shall be raised to 107 K.

Nuclear fusion at very high temperature

Thermonuclear Reactions

An alternate and Practically

inexhaustible source of energy

if put in Use.

Fusion in Laboratory

• To overcome Coulombic repulsion, must have very energetic D, T

(~70 keV Temp. 8×108 oC)

• At this temperature, D,T nuclei are ionized, form a charged

plasma

• No material can withstand this temperature

• The easiest fusion reaction to attain is

Deuterium + Tritium:

3H + 2H 4He + 1n

D + T +n

Three Confinement Methods

High-power laser confinement

Nuclear Fusion and Plasma Confinement

FUSION REACTOR TECHNOLOGY

Proposed Types of Reactors

• Magnetic Confinement Fusion (Tokamak)

• Inertial Confinement Fusion (ICF) : Laser Ignition

MCF is about 20

years ahead of ICF

Magnetic Confinement

• Charged plasma can be confined by large magnetic fields,

requiring superconducting electromagnets.

• Fusion reaction occur,

and the energy released

makes the He byproduct

more energetic, thus

keeping the temperature

of the plasma hot enough

to „burn‟ D,T

TOKAMAK

ICF- Schematic

Inertial Confinement Conditions for controlled fusion reactions;

Extremely high temperatures (108 K) and pressures

very hard to produce

Possible through use of high energy Laser pulses from

many directions simultaneously Inertial Confinement

Argus Laser System, USA,

Shiva System – 20 lasers

directed from 20 directions

Delphin System in USSR-256 beams launched through 256

amplifiers.

Laser Fusion Projects

Based on Nd:glass lasers

An inertial confinement fusion implosion on the NOVA laser creates

"microsun" conditions of tremendously high density and temperature

rivaling even those found at the core of our Sun.

Inside the main chamber of Nova

( National Ignition Facility)

National Ignition Facility (NIF)

America Fires the Most Powerful Laser in History (2010): United

States' National Ignition Facility at Lawrence Livermore National Lab in

California has fired the most powerful laser in history, a record-breaking 2MJ

shot. The laser was originally designed to reach 1.875 MJ, but beat everyone's

expectations set a new world record in the process.

192 laser beams (UV) combined to form the

single shot, initially reaching 1.875 MJs.

Better yet, the blast caused less damage to

the laser optics than predicted, which

allowed the facility to fire another shot just

36 hours after the 2.03 MJs one.

“It's a remarkable demonstration of the laser from the standpoint of its energy, its precision, its power, and its availability.”

- Ed Moses, Director, NIF

Fusion Schematic in NIF

• 192 Laser beams in single shot

Target assembly for NIF's first integrated ignition

experiment mounted in the cryogenic target positioning

system (cryoTARPOS). The two triangle-shaped arms

form a shroud around the cold target to protect it until

they open five seconds before a shot.

NIF and ICF

Future Fusion Research

ITER : International Thermonuclear Experimental Reactor

• A Joint Project Conducted by: European Union , Russian Federation, United States , Canada, Japan and India.

Large scale Tokamak being built in France, to be operational 2016

2nd largest international scientific collaboration in history

• The Purposes of ITER are:

– Demo that electrical power from fusion is scientifically and technically

feasible

• Results of Practical Electric Power from ITER are Probably

10-20 years away

Laboratory experiments have given positive results,

however, nuclear fusion reactors remains an unproven

technology after seven decades of expensive research

ICF research continues, but magnetic confinement

seems closer to the goal of a working fusion reactor.

FUSION REACTOS The Energy

Source of Future ?

Conclusions

Laser is an Intelligent Light Wave Technology.

Laser can perform All Technological Tasks.

Laser can perform in All Areas of Studies.

Laser can perform Low to High Extreme End.

Laser can perform well with High Accuracy.

Laser Should be used in A Creative Way.

We are on the web at

http://www.nitttrchd.ac.in

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The End

See you Next Time !