NON-CONVENTIONAL MACHINING

Materials

Conductive Non-Conductive

1) LASER BEAM MACHINING Content :1. History2. What is LBM 3. Laser4. Types of laser5. Laser application6. Parameters affecting LBM 7. Advantages 8. Disadvantages

1) LASER BEAM MACHINING

WHAT IS LBM ?

• It’s a non-traditional subtractive manufacturing process

• It uses thermal energy to remove material from metallic or nonmetallic surfaces.

• Its best suited for brittle materials with low conductivity, but can be used on most materials

Electrical Energy LASER

Thermal Energy

Heating of the surface

Melting of the surface

Vaporizing of the surface

Material Removal

WHAT IS LBM ?

2) ELEMENTS OF LASER :1. Optical Feedback element2. Lasing medium3. Pumping Process 4. LASER

HOW DOES IT WORK ? “‘SPONTANEOUS EMISSION’”

Types of Laser Gas Laser

Solid State Laser

Excimer Laser

2) ELEMENTS OF LASER :

GAS

LASER

•Helium•Neon•Argon•CO2 etc.•Operated in continuous mode

SOLID STATE

•Ruby -wavelength of 0.7 μm•Nd-glass - wavelength of 1.64 μm•Nd-YAG-wavelength of 1.06 μm•Operated in Pulse mode.

2) ELEMENTS OF LASER :

• Exciting the gas atoms or molecules by pumping it with flash lamps.

• Stimulated emission of photons could be in all directions.

HOW DOES IT WORK ? GAS LASER

HOW DOES IT WORK ? SOLID STATE LASER

5) APPLICATION :

Applications

Material Removal

CladdingWelding

5) APPLICATION : MATERIAL REMOVAL

CUTTING DEPTH :

In drilling, energy transferred (Nd:YAG laser) into the workpiece melts the material at the point of contact, which subsequently changes into a plasma and leaves the region.

A gas jet (typically, oxygen) can further facilitate this phase transformation and departure of material removed.

Laser drilling should be targeted for hard materials and hole geometries that are difficult to achieve with other methods.

LBM can make very accurate holes as small as 0.005 mm in refractory metals ceramics, and composite material without warping the workpieces.

• Used for welding ceramics and dissimilar material s like steel and aluminum

• Produces maximum penetration & minimum distortion in the material .

5) APPLICATION : WELDING

5) APPLICATION : WELDING

• Laser Cladding or Laser Deposition is a processing technique used for adding one material to the surface of another in a controlled manner.

• Laser beam is used to create a shallow melt pool.

5) APPLICATION : CLADDING

5) APPLICATIONS:

• Hair removal • Density Medical • Wire stripping Electronic • Drilling • Cutting • Welding• Cladding

Manufacturing

5) APPLICATIONS:

ADVANTAGES : • No machining force or wear of the tool takes place. • Large aspect ratio in laser drilling can be achieved along with acceptable accuracy or

dimension, form or location • Micro-holes can be drilled in difficult – to – machine materials • Though laser processing is a thermal processing but heat affected zone specially in pulse

laser processing is not very significant due to shorter pulse duration. • No limit to cutting path as the laser point can move any path. • The process is stress less allowing very fragile materials to be laser cut without any

support. • Very hard and abrasive material can be cut. • Sticky materials are also can be cut by this process. • It is a cost effective and flexible process. • High accuracy parts can be machined. • No cutting lubricants required

DISADVANTAGES :

• Uneconomic on high volumes compared to stamping • Limitations on thickness due to taper • High capital cost • High maintenance cost • Assist or cover gas required

COMPARISON :