Laser cutting machine cutting quality assessment

Laser cutting machine processing quality is not qualified, how much trouble will bring?

Laser, a new birth, let the day attack turned upside down change. About this mysterious and ethereal thing, need to know too much, but today's theme as long as one: laser cutting machine processing quality. You'll see what it is.

Originally, the quality evaluation of laser cut, haven't a consistent international specification, but this is not to say that no specification completely, give priority to with EU about ISO9000 series quality to ensure supply of methods, from the cut quality grades to distinguish, standard set of samples and sample processing, optical system, offer the model of the sample and the beam characteristics, etc., Further study on the laser cutting specification and sample specification rules.

Specification and evaluation

1 cut lubrication, no stripes, no brittle fracture

When a high-speed laser cutter cuts through a thick plate, the molten metal does not appear at the bottom of the straight laser beam, but rather squirts out at the back of the beam. As a result, the zigzag texture is formed at the edge of the cut, and the texture closely follows the moving laser beam. To correct this problem, decreasing the feed rate at the end of the cut process can greatly eliminate the texture formation.

2 slit width is narrow, and the connection of laser beam spot diameter

Cutting width generally does not affect the quality of cutting, only in the internal components of a very precise summary, the width of cutting has a major impact, this is because the width of cutting resolution of the summary of the minimum internal, when the thickness of the plate is added, the width of cutting is also added. So to ensure equal precision, no matter how large the cutting width, the workpiece in the processing area of the laser cutting machine should be stable.

3. Good slit straightness, small heat affected zone

For the processing of data below 5mm, the straightness of section may not be the most important evaluation factor, but for high-power laser cutting, when the thickness of processing data exceeds 10mm, the straightness of cutting edge is very important. Away from the focus, the laser beam becomes divergent and, depending on where the focus is, the slice widens toward the top or bottom.The cutting edge deviates from the straight line of the pen by a few hundredths of a millimeter. The straighter the edge, the higher the cutting quality.

4 NO data incineration, NO melting layer composition, NO large slag

The hanging slag of laser cutting machine is mainly shown in the accumulation and section burr, accumulation is due to the laser cutting at the beginning of the melting perforation before the workpiece surface hit a layer of special liquid containing oil. Gasification of all kinds of data do not have to be blown off by the wind, but up or down discharged will also form a pile in the appearance; The composition of burr is a very important factor to determine the quality of laser cutting. Because the removal of burr requires extra work, the severity and quantity of burr can intuitively judge the quality of cutting.

Cut off the connection between the size of the surface roughness and the surface quality

For metal laser cutting machine, many people may not understand, originally cut section texture and roughness has a direct relationship, when the roughness of the section texture is relatively high, but because of the difference in the cause of the two effect, analysis of cutting machine processing quality, still choose separation analysis.

The depth of the straight texture of the cutting mechanism determines the roughness of the cutting surface. Shallow texture, cutting surface lubrication, deep texture, rough, conflict, cutting quality is very low.

6. Thermal influence of cutting data

Hot opening processing is a typical feature of laser cutting, that is to say, in the process of application, it will form a thermal effect on the metal data, mainly shown here: 1. Heat affected area; 2. Depression and corrosion; 3. Data distortion.

The heat affected zone refers to the area adjacent to the laser cutting that is heated and the structure of the metal changes. For example, some metals harden. It is generally the depth of the area where the internal structure changes; Depression and corrosion have an effect on the appearance of the cutting edge. If the cutting causes the parts to be heated rapidly, deformation is common. This is particularly important in precision machining, as the sheet and connector are generally only a few tenths of a millimeter wide. Controlling laser power and using short laser pulses can reduce component heating and avoid deformation. In addition to the above criteria, the condition of the melting layer and the final molding in the processing process directly affect the above processing quality evaluation objectives.

Factors affecting the roughness of laser cutting:

(1) The inherent parameters of the cutting system, such as spot form, focal length, etc.;

(2) technical parameters that can be adjusted during cutting, such as power size, cutting speed, auxiliary gas type and pressure, etc.;

(3) physical parameters of processing data, such as the absorption rate of laser, melting point, viscosity coefficient of molten metal oxide, metal oxide surface tension, etc.

Of course, here is not completely comprehensive, in addition, the thickness of the workpiece also has a great impact on the surface quality of laser cutting, the smaller the thickness of the workpiece, the higher the roughness of the surface.