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SEMINAR ONLASER
MICROMACHINING
Department of mechanical engineeringFaculty of Engineering and TechnologyM.J.P. Rohilkhand University, Bareilly
Nov,2015
Anil chaurasiya12ME08
BYSeminar Guide- Dr. T.U. SiddiquiCo-guide-Mr. Vineet Tripathi
IntroductionWorking principleClassificationApplicationAdvantage and disadvantageSafetyReferences
Contents:
Laser micromachining: cutting, drilling, welding, or other modification in order to achieve small features.
Micro machining implies that parts are made to the size of 1 to 999 µm. However Micro also means very small in the fields of machining, manufacture of small parts are not easy.
Introduction
Micro pattern machined on a steel plate inless than 0.5 secondsSource-https://engineering.purdue.edu/LAMPL/research_micro%20machining.html
Continued...Lasers have been in use in various industrial sectors such as the automotive and aerospace industries for many years performing cutting, welding and materials processing tasks.
Working Principle The laser beam is focused onto the work piece and can be moved relative to it.
The laser machining process is controlled by switching the laser on and off, changing the laser pulse energy and other laser parameters and by positioning either the work piece or the laser focus. A laser machine consists of the laser, mirrors for beam guidance, a focusing optic and a positioning system.
Setup of laser micromaching
Continued...
Components use in laser micromaching
Continued... Laser is emitted from the source is passed through the energy attenuator. After it is passed through the beam homogenizer to homogenize the beam.
The target illuminator and machine vision controls the beam to the focusing lens. The lens is moved by precision motion stages. The beam is then falls on the work piece and the machining takes place.
Types of Laser Micro Machining
1. Direct writing. 2. Mask Projection
Process Parameters Effect
Wavelength,Focal length of lens
Feature size
Beam shape Feature shape
Beam energy,Pulse width
Size of heat affected zone
Depth of focus Aspect ratio
Continued...
DIFFERENT TYPE OF LASER AND THEIR USES IN INDUSTRY
APPLICATION LASER TYPECutting
MetalsPlasticsCeramics
DrillingMetalsPlastics
MarkingMetalsPlasticsCeramics
Surface treatment (metals)Welding (metals)
PCO2; CWCO2; Nd:YAG; rubyCWCO2PCO2
PCO2; Nd:YAG; Nd:glass; rubyExcimer
PCO2; Nd:YAGExcimerExcimerCWCO2PCO2; CWCO2; Nd:YAG; Nd:glass; ruby
Note: P = pulsed, CW = continuous wave.
SCANNING ELECTRON MICROSCOPE IMAGES
SEM images of micro-trenches formed by laser micromachining at different focus offset plane.Source-www.intchopen.com
Fabrication of Micro Structures on Metals by Femtosecond Laser Micromachining(SEM)Source-www.mdpi.com
HEAT AFFECTED ZONE IN LONG-PLUSE LASER AND ULTRSHORT-PLUSE LASER
Source-www.cmxr.com
For drilling micro holes, laser beam drilling technique
is used.
Applications
High speed drilling of 20µm holes in 50µm thick foil
Cutting of 1mm tube
100µm wide v-grooves
Continued...
100 um holes drilled in 75mm high-density polyethylene with (a) a twist drill bit (b) a KrF laser.Source-://www.exitech.co.ukhttp
(a) (b)
Laser Micro machining technique finds application in the manufacture of micro channels and micro holes in integrated chips and microchips.
Micro holes on integrated chips Micro channels on integrated chips
Continued...
Surface micro machining is characterized by the fabrication of micro mechanical structures from thin deposited thin films.
Continued...
Used in machining threads in a single polyfibre and also used to give taper to the fiber.
Continued...
Easy capability of being automatedStraightforward process monitoringForceless and contactless machiningMinor heat-affected zoneMarginal modifications to the microstructureHigh flexibility regarding design of tiny structuresHigh machining speedHigh precisionConstant machining qualityNo additional tooling costs by wearNo solvent chemicals usedMaterial removal rate controllable down to the nanometer scale
Advantages
The equipment required for micro machining is very costly than other cutting processes.Need highly skilled persons to operate micro machining systems.Material limitations (including crystalline and reflective materials)Reflected laser light can present a safety hazard
Disadvantages
High intensity ultraviolet and infrared light hazardous to the eyes (cornea) and skinDuring normal operation of the equipment Interlocked protective housing is must.Required safety labels, inspections and record keeping.
Safety
Mechanical safety Large motion control systems may pose mechanical hazards to people Mechanical guards Machine must be checked regularly
Lethal high voltages in the laser headElectrical safety coversQualified service personnel only
Electrical safety
Toxic and corrosive fluorine and chlorine gasesCompressed gas cylinders need proper handling
Material safety
Micro machining technology not only provides a new manufacturing route for existing products, but also allows the creation of completely new products.
The surface micro machining technology predominates at the present state & this trend will continue in the future.
Nano is the buzz word of the moment. Thus the transition from Micro-Electro-Mechanical-Systems (MEMS) to Nano-Electro-Mechanical systems (NEMS) is taking place in present technology
Conclusion
Advancements in Laser Micro machining Techniques- By Nadeem Rizvi and Paul Apte.Laser Micromachining – By Udo Klotzbach, Andres Fabian Lasagni, Michael Panzner and Volker Franke.www.resonetics.comInternet(Wikipedia, Google etc)www.mdpi.comwww.extich.co.inwww.itechopen.comhttp://www.springer.com
References
Thanks for Listening!!