Notes on the laser

The cost of the CO2 lasers has mitigated against their general acceptance by industry, except for heavier work. They can perform welding, cutting, drilling, spot welding and marking operations quickly and efficiently, with very little distortion, due to the narrow HAZ, but it is still only the larger firms that use them where there is much repetition work. We will discuss the following types of laser here: solid state, such as the Nd–YAG, and gas, such as the CO2 axial flow and the CO2 transverse or cross flow.

The Nd-YAG laser

The Nd-YAG laser is of neodymium and yttrium-aluminium garnet (the last word indicating that its crystals are cubic). This laser is relatively light and portable, and its use is greatly increased by the fact that the laser beam can be conducted along a fibre-optic cable to a gun head, and can thus reach awkward places. It is used for marking hardened parts and no matter how thin, these are clearly marked using a low-power laser (Fig. A14.1). The drilling of thin sheet and stainless steel is performed with a very small focussed beam; the width of the beam determines the hole diameter.