Laser cutting machine is the largest industrial application of higher power lasers. It is used in industry in a range of applications from prototyping and smaller batch manufacturing up to continuous production line systems. The process lends itself to automation with offline CAD/CAM systems controlling either 3-axis flat bed systems or 6-axis robots for three dimensional laser cutting.
In recent years the increase in laser cutting has been dramatic, replacing more conventional mechanical processes due to increased flexibility. The improvements in accuracy, edge squareness and heat input control means that other profiling techniques such as plasma cutting and oxy-fuel cutting are being replaced by laser cutting.
Types of Laser Cutting Machine
There are three types of lasers. The CO2 laser is suited for cutting, boring, and engraving. The neodymium (Nd) and YAG is usually called 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.
Design Considerations
Lasers cut by melting the material in the beam path. Materials that are heat treatable will get case hardened at the cut edges. This may be beneficial if the hardened edges are functionally desirable in the finished parts. However, if further machining operations such as threading are required, then hardening is a problem.
A hole cut with a laser has an entry diameter larger than the exit diameter, creating a slightly tapered hole.
The minimum radius for slot corners is 0.75 mm (0.030 in). Unlike blanking, piercing, and forming, the normal design rules regarding minimum wall thicknesses, minimum hole size (as a percent of stock thickness) do not apply. The minimum hole sizes are related to stock thickness and can be as low as 20% of the stock thickness, with a minimum of 0.25 mm (0.010 in) for upto 1.9 mm (0.075 in). Contrast this with normal piercing operations with the recommended hole size 1.2 times the stock thickness.
Burrs are quite small compared to blanking and shearing. They can be almost eliminated when 3D lasers are used and further, eliminate the need for secondary deburring operations.
As in blanking and piercing, considerable economies can be obtained by nesting parts, and cutting along common lines. In addition, secondary deburring operations can be reduced or eliminated.
References:
http://www.sxwo.cn/industrial-supplies
http://www.consumer-manual.com/english
http://en.wikipedia.org/wiki/Laser_cutting