Fusion cutting is another standard process
employed in processing metals. But it can also be used
in cutting other fusible materials such as ceramics.
Nitrogen or argon is used as the cutting gas here. The
gas is blown through the kerf at pressures ranging from 2 to
20 bar. Argon and nitrogen are inert gases. This means that
they do not react with the molten metal in the kerf, but only
blow it out toward the bottom. Simultaneously, they shield
the cut edge from the air.
Nitrogen is suitable for use with almost all metals. The
exception is titanium. Titanium reacts violently with both oxygen
and nitrogen; therefore, argon is used to cut it.
The great advantage of fusion cutting: cut edges are oxide
free and do not require further treatment. Nevertheless, the laser
beam must supply all of the energy needed for cutting. For
this reason, cutting speeds as high as those in flame cutting
can be achieved only in thin sheets. Piercing is also more difficult.
Some cutting systems allow you to use oxygen to pierce
the material and then switch over to nitrogen for cutting. | 