The application of air as auxiliary gas in fiber laser cutting system

How to reduce the cost of laser cutting equipment is very urgent.
This paper will focus on the use of air as an auxiliary gas in fiber laser cutting process to reduce the cutting cost.

The influence of different auxiliary gas on cutting quality.

(1) oxygen as aided gas, while blowing away from the molten metal liquid oxidizing reaction.

will also promote the endothermic melting metal.

so as to realize the fusion of thicker material.

a process that can significantly improve the processing ability of the laser.
But it is also due to the presence of oxygen, can make the cut surface of materials have obvious oxidation

and quenching effect on cut surface materials around, can improve the hardness of this part of the material

a certain influence on the subsequent processing.

When the nitrogen is used as the auxiliary gas, the protective atmosphere will be formed around the molten metal liquid to prevent the material from being oxidized,

thus ensuring the cutting surface quality.

But at the same time, because nitrogen has no oxidation capacity to increase heat transfer.

it does not help to improve cutting ability like oxygen.
In addition, as nitrogen is used as an auxiliary gas, nitrogen consumption is very large.

resulting in higher cutting costs than other gases.

(3) the composition of the gas in the air

nitrogen accounted for about 78%, oxygen accounted for about 21%, when using air as auxiliary gas cutting,

due to the presence of oxygen oxidizing reaction makes the cutting section is necessarily,

but at the same time as a result of the existence of a large number of nitrogen, oxygen oxidation reaction of low enough to enhance heat transfer

cutting ability won’t raise, so air cutting effect can  understood as somewhere between nitrogen and oxygen cutting

cutting and benefits is air cutting cost is very low

all cost is caused by the air compressor to provide air power consumption.

and the consumption of the air line filter.

The effect of air as an auxiliary gas on cutting.

In the case of carbon steel plate, when the air is used as auxiliary gas cutting.

the part section will produce a smaller burr.

but the burr is not sharp and can be applied to the parts that are not high enough for the burr.

Diction for stainless steel plate, due to the air as auxiliary gas, material cutting surface after machining is oxidation.

resulting in the cutting section when making welding oxide will produce slag inclusion and porosity in the weld defects such as

affect the weld quality, which led to the decrease of the strength of welding parts.
Therefore, it is necessary to polish the oxide layer of the section of the welding section to improve the welding quality after the use of air as the auxiliary gas to complete the cutting of the parts.
In addition, after cutting, the section will oxidize, producing a yellow oxide layer. If the part is the appearance, it will have an effect.
The oxide layer also has an effect on the welding process.auxiliary gas in laser cutting

It is necessary to polish the oxide layer before the welding operation  done.

For aluminum and aluminum plates, the use of air as an auxiliary gas can reduce the cutting burr.

If nitrogen is use，the cutting burr will be larger.