The most common laser application in the mechanical engineering industry is laser cutting using a high power laser. Laser is best suited for cutting thin pieces that must have precise dimensions.
Laser cuts materials so cleanly that the pieces can be used as is, or sent to further processing without the need for post-cut finishing. Laser cutting is used extensively especially in mechanical engineering companies that serve the automotive industry, and also in the manufacture of household equipment, such as dishwashers, washing machines, etc.
The focused laser beam is so powerful that it directly vaporizes the material to be cut. Laser can also cut many other materials besides metals, such as plastic, wood, and so on. When cutting metals, the cutting gas is usually oxygen or nitrogen. The laser beam is focused through a lens on the material to be cut, which melts. The cutting gas is fed through a concentric nozzle to blow away the molten material.
The application determines which of the gases, oxygen or nitrogen, is better suited for the task. Oxygen reacts exothermically (generates heat) with the material. The extra heat generated by oxygen enables a much faster cutting speed than with nitrogen. As a result, oxygen is the most important cutting gas for cutting non-alloy and low-alloy steels. The purity of gas directly affects the cutting speed.
However, using oxygen creates an oxide layer on the cut surface, which might create a problem. Oxygen is not well suited for cutting stainless steel, because the steel will lose its corrosion resistance. Aluminum surfaces cut with oxygen are uneven and burred. To get a clean, oxide-free cut surface, nitrogen must be used when cutting these materials. However, the purity of nitrogen is crucial, since even a trace amount of oxygen in the cutting gas can destroy the corrosion resistance of stainless steel.
Sensitive materials, such as titanium and zirconium must be protected against oxygen and nitrogen, i.e. the air. These materials are cut with super-pure argon, preferably in an argon-filled chamber.
AGA LASERLINE® gases and gas supply systems help to ensure that your cutting activities continue to be high-tech and economical from start to finish.
To avoid the risks in hot work, always adhere to safety precautions.