Laser cutting technology is widely used in industry due to its advantages of high precision, fast speed and low impact on the material body. In the aerospace field, laser cutting is mainly used for blanking and hole-cutting operations of thin-walled parts and sheet metal parts to prepare for the next step of sheet metal forming and welding.

In the aviation manufacturing industry, the surfaces to be welded of parts are cut by laser. What are the requirements for laser cutting technology? How to evaluate and control the laser cutting process? This question will be answered below.

Cutting process requirements

When the laser cutting surface is also a welding surface, the laser cutting process should be marked as an important process in the parts manufacturing flow card and needs to be verified during the product materialization process.

Under the preset cutting process conditions, metallographic analysis is performed on the cut samples to measure the size of the remelted layer, whether there are micro-cracks, etc., to ensure that the results meet the requirements of physical verification.

When performing laser cutting, the most important point is to use inert auxiliary gas to protect the cutting area and the molten metal on the cutting surface and prevent the introduction of air to cause pollution. Reactive gases such as oxygen and carbon dioxide are absolutely not allowed to be used as auxiliary gases for aerospace materials. Whether nitrogen can be used depends on the material to be cut.

Is the molten layer retained?

The remelted layer may be difficult to meet all the requirements for physical verification due to limitations in size and structure. The remelted layer cannot be completely removed, or can only be partially removed, partially retained, or even completely retained.

At this time, it is necessary to see whether the remelted layer can be completely melted during welding, and conclusions must be drawn through welding experiments and metallographic tests.

Whether the remelted layer is allowed to remain fully or partially on the part must be submitted to the customer for special approval.