(15/3/2023)

Copper processing conditions and cutting problems and their countermeasures【Phenomena】

When cutting various materials with auxiliary nitrogen and cutting copper with auxiliary oxygen effect comparison. At the same cutting speed, the required output power when cutting copper is about 3 times that when cutting stainless steel.

In the thin plate cutting of copper, the amount of thermal deformation generated during processing is larger than that of other materials.
Especially when the margin is very narrow, the amount of thermal deformation in the upper and lower directions will be large, which will hinder the profiling action of the nozzle and even affect continuous processing. Parts or fragments that fall into the scrap bin after being cut will also reflect the laser light.

Falling materials have random reflection angles of reflected light, so sufficient care is required

Since copper has a high reflectivity to laser light and a high thermal conductivity, the heat energy generated by laser melting is easily lost to the mother metal.
in the material. Copper cutting requires a greater output power than other materials. In addition, the copper material will produce a large
Thermal deformation, resulting in deviation of the focus position and thus processing defects.

It shows the schematic diagram and precautions after decomposing each process in the processing.

(1) The basic method of copper cutting is to apply a beam absorber on the surface of the workpiece to reduce the reflectivity. with other materials
More energy will be required to cut copper than copper.

(2) Considering that the workpiece will be deformed rapidly when the laser is irradiated during the perforation process, it is necessary to obtain a good
For processing, it is necessary to set the processing conditions to high energy conditions that are sufficient for melting even if the focus position deviates. set to
Under the conditions of high peak output power, rectangular pulse waveform, and low frequency, the energy used for processing in each pulse can be increased.

(3). If the cutting quality gradually deteriorates from good to good, it can be considered that the focus position occurs during laser irradiation
changed. The change of the focus position is mainly due to the thermal lens effect caused by the dirty optical components or the heat generated by the workpiece.
resulting from deformation.
The way to solve the thermal lens effect is to clean the optical components. If it still cannot be restored, it should be replaced;
The way to shape is to set up micro-joints or use workholding to suppress thermal deformation.

(4) Apply laser absorber on both sides of the material, which can effectively prevent the reflection of the laser from the material dropped in the waste bin.