The growing popularity of laser cutting

Lasers offer a form of energy that has uniquely lent itself to manufacturing, medicine, and communication. Lasers have the ability to heat and melt multiple types of materials. It can even be used to vaporize material as required. It is an optimum way to utilize intense but controllable energy. As of date, one of the most used applications of lasers is in cutting. There are four different types of cutting.

Fusion cutting

In this technique, the material melted to some extent, and then this molten material is expelled by using an airflow. This process is called a fusion laser cutting process due to the transfer of material happening when it is in a liquid state,

How it works: The laser beam directed at the material is accompanied by an inert cutting gas. This makes the now molten material leave the slot that was created. The inert gas has no role in the cutting, however. Fusion cutting is far more efficient and faster than conventional gasification.

In this process, the laser beam is partially absorbed. An increase in laser power also increases the cutting speed. The speed, however, gets lowered as the plate thickness increases. It is also dependent on the melting temperature of the material getting cut. When the laser power is below a certain level, the limiting constraint is the air pressure at the slot and the thermal conductivity of the material.

While laser fusion cutting can be used for most materials, it does not get the oxidation incision needed for steel and titanium. There is a little bit of melting but the laser power density that is needed for gasification is not adequate.

Vaporization cutting

During laser gasification, the surface temperature of the targeted material reaches boiling point very rapidly, and even heat conduction to does not cause melting.

How it works: A partial amount of material gets vaporized into steam while some get blown away due to auxiliary gas flow from the bottom of the slit. Such a process calls for very high laser power.

It is important to note that to halt any vapor from condensing into the slit wall, the thickness of the material getting cut cannot be greater than the laser beam diameter. This process is viable in processes where there is a need to avoid the removal of any molten material. It is widely used in ferrous alloy applications. This technique cannot be used for wood and certain ceramics that don’t have a molten state. In laser gasification cutting, the optimal beam focusing is a function of material thickness and quality of the beam. For plates below a certain thickness, maximum cutting speed is restricted by the velocity of the gas jet.

Fracture-controlled cutting

High-speed and controllable cutting using laser beam heating is the usual norm while working on brittle materials. These materials are usually prone to heat damage. This process is called fracture-controlled cutting.

How it works: A laser beam is used to heat the small area of the brittle material, causing a large thermal gradient and serious mechanical deformation in the region, and leading to the crack of the material.

As long as the balanced heating gradient is maintained, the laser beam can guide the cracks in any desired direction.

Oxidation melting cutting

This is also called a flame cutting process and uses an inert gas. Oxygen or any other reactive gas, can also be used as a source of heat.  

The cutting speed for the same thickness of structural steel might be quicker than the fusion cutting process but the cutting incisions may not be as good. Hence this process is not used for machining precision models or even sharp corners. In the case of certain laser power, the constraint is the oxygen supply and the thermal conductivity of the material.

 

Hunt and Hunt is a leading precision machining organization based in Houston, Texas. Hunt and Hunthas delivered precision machining services for a variety of clients. Its capabilities in regard to tubular laser manufacturing allow it to effectively serve clients from a wide spectrum of industries.