what is Laser cutting?

March 17, 2009 | tags | views
Comments 0

Laser cutting is a technology that uses a laser to cut materials, which is used in the production line and is typically used for industrial manufacturing applications. Laser cutting works by directing the output of a high power laser, by computer, at the material to be cut. The material then either melts, burns, vaporizes away, or is blown away by a jet of gas,[1] leaving an edge with a high quality surface finish. Industrial laser cutters are used to cut flat-sheet material as well as structural and piping materials.

Advantages of laser cutting machine over mechanical cutting vary according to the situation, but two important factors are the lack of physical contact (since there is no cutting edge which can become contaminated by the material or contaminate the material), and to some extent precision (since there is no wear on the laser). There is also a reduced chance of warping the material that is being cut, as laser systems have a small heat-affected zone. Some materials are also very difficult or impossible to cut by more traditional means. One of the disadvantages of laser cutting includes the high energy required.

There are three types of lasers. The CO2 laser is suited for cutting, boring, and engraving. The neodymium (Nd) and neodymium yttrium-aluminum-garnet (Nd-YAG) lasers are identical in style and differ only in application. Nd is used for boring and where high energy but low repetition are required. the Nd-YAG laser is used where very high power is needed and for boring and engraving. Both CO2 and Nd/ Nd-YAG lasers can be used for welding.[2]

Common variants of CO2 lasers include fast axial flow, slow axial flow, transverse flow, and slab.

CO2 lasers are commonly "pumped" by passing a current through the gas mix (DC Excited) or using radio frequency energy (RF excited). The RF method is newer and has become more popular. Since DC designs require electrodes inside the cavity, they can encounter electrode erosion and plating of electrode material on glassware and optics. Since RF resonators have external electrodes they are not prone to those problems.

In addition to the power source, the type of gas flow can affect performance as well. In a fast axial flow resonator, the mixture of carbon dioxide, helium and nitrogen is circulated at high velocity by a turbine or blower. Transverse flow lasers circulate the gas mix at a lower velocity, requiring a simpler blower. Slab or diffusion cooled resonators have a static gas field that requires no pressurization or glassware, leading to savings on replacement turbines and glassware.
 


    Other article:



:

nothing