Laser Beam Welding Welding Technology/4.4 Laser Beam Welding

Laser Beam Welding The laser beam is focused onto the workpiece by a set of mirrors. When the laser beam is moved relative to the workpiece, the energy of the focused laser beam melts the metal so that a joint is formed. Welding Technology/4.4 Laser Beam Welding

Laser Beam Welding The word laser stands for Light amplification by Stimulated Emission of Radiation. When an electron of atom absorbed energy form an external source, the electron which are in its original energy level, jump to a higher energy level. This is not a stable condition of atom so this electron emits the absorbed energy in form of photons and come back to its original state. If an atom which is already at higher energy level absorbs energy, it will emit double energy to return at its original state. Welding Technology/4.4 Laser Beam Welding

Laser Beam Welding The energy emitted by the atom has same frequency and wavelength as the stimulating energy. This is fundamental of laser. When the laser material placed in presence of some other energy source, it absorb energy at some extant and release it when reaches its absorbing limit. This high amplified light beam is called laser. Welding Technology/4.4 Laser Beam Welding

Laser Beam Welding Welding Technology/4.4 Laser Beam Welding

Working First laser material CO2 or other gases filled into laser discharge tube. Now switch on the power supplied which is connected by flash lamp. This lamps produce light energy which used to excite electrons of atom. The atoms of laser material absorb energy from the light energy produced by flash lamp. It leads jump of orbital electron of atom form low energy level to high energy level. This is unstable condition of atom. This energy initially blind up in laser material. When the atoms absorb sufficient energy it start emit energy continuously. This is high amplified same frequency and same wavelength coherent light. This laser light collected by the focus lens and directed toward the work piece. Now the laser impinging on work piece start machining process by melting or vaporize material from contact surface. Welding Technology/4.4 Laser Beam Welding

Application Used to drill small hole of diameter about 0.005 mm in refectory and ceramic materials. It is used in drilling and cutting for both metals and non-metals. It is extensively used in electronic and automotive industries. It is mostly used in aerospace industries. Used to machine complex profile where machining by tool is not possible. Welding Technology/4.4 Laser Beam Welding

Advantages It can cut all material. No tooling cost because no physical tool is required. It produces finish part or high surface finish. No tool wear because no physical tool is used. Micro holes can be drilled accurately. Complex shape can be machined easily because laser can be move in any path. Very hard material can be cut through laser beam machining. High accuracy can be achieved. It can be easily automated and flexible.  Welding Technology/4.4 Laser Beam Welding

Disadvantages It is uneconomical when high volume of same shape to be cut compare to stamping. High capital and maintenance cost. It cannot use to produce blind hole. Laser can leads to safety hazards. Welding Technology/4.4 Laser Beam Welding