Learn about Plasma Cutting: How It Works And Benefits

What is plasma cutting? How does the process work? What gases are best used in this process? What materials are plasma cutters suitable for? Read on as we answer these questions in detail and provide you with other important information about plasma cutting.

What is plasma cutting?

Plasma cutting is a metal fabrication process that uses ionized gas 0C heated to more than 20,000 degrees Celsius to melt metal materials. This gas is sprayed at high pressure to melt the material and remove it from the cut.

It is important to note that this process is only applicable to conductive materials such as stainless steel, copper, aluminum, and other metals. In other words, plasma cutting cannot cut stone, paper, glass and other bad conductors of electricity.

The technology is unmatched in cost-effectiveness when cutting thick metals. In addition, it is versatile and the tool maintenance cost is low. It also has high cutting accuracy, making it ideal for cutting parts with complex geometrics.

How does the process work?

The plasma cutting process involves using heat to melt metal instead of cutting mechanically. Plasma cutters work by sending an arc through a gas. The gas then passes through a contracted opening (nozzle). The restricted opening causes the gas to squeeze through at high speed, forming a plasma. Cutting the workpiece requires the cutting tip of the plasma cutting machine to withstand the workpiece. Also note that due to the electrical conductivity of the plasma, the workpiece needs to be grounded through the cutting table.

Not all plasma cutting systems work in the same way. However, there are three types of cutting processes.

Three cutting processes

1, High frequency contact: This is a low budget format. In addition, due to the risk that its high frequencies will interfere with modern equipment, the process is not suitable for CNC plasma cutting machines. High frequency contact cutting involves the use of high frequency sparks and high pressure - the plasma torch forms a spark when it comes into contact with the cutting metal. The contact closes the circuit, triggers a spark, and produces plasma for cutting.

2, Arc initiation: During this cutting process, a spark is generated inside the cutting torch by a combination of a low current circuit and a high voltage. This spark helps create a guide arc, a small amount of plasma. Upon contact with the workpiece, the plasma cutter creates a cutting arc, enabling the mechanic or operator to begin the cutting process.

3, Spring-type plasma head: To create a short circuit, the operator presses the cutting torch to the workpiece. After the short circuit, the current begins to flow. To create an arc, the operator releases pressure.

What gases are best used in this process?

The type of gas used in this process depends on the cutting method, cutting material and thickness. In addition to ensuring the formation of the plasma jet, the gases used should also help to expel molten material and oxides from the incision. The most commonly used gases for plasma cutting include:

Argon, Nitrogen, Air (air is 78% nitrogen and 21% oxygen), Oxygen, Hydrogen

What materials are plasma cutters suitable for?

There are many materials available for plasma cutting. This is mainly because the process can cut any conductive material. The following are the most commonly used materials for this technology.

Aluminum material, Mild steel, Stainless steel, Brass, Copper, Cast iron,

What are the advantages of plasma cutting?

1, High cutting quality

Cutting with plasma cutters provides higher cutting quality for metal compared to other metal manufacturing processes such as flame cutting. This is due to the fact that there is no residual scum at the edge of the metal incision and the heat affected zone area is small.

2, Versatility and flexibility

This process can cut any metal that conducts electricity, which makes it so versatile. It can easily cut medium and high thickness aluminum, high alloy steel and other metals. It is ideal for groove cutting, planning or marking metal. In addition, the process can also cut metal in water with reduced noise levels.

3, High speed

Plasma cutting is 100 times faster than laser cutting and about 10 times faster than flame cutting. In other words, it increases productivity and reduces the time spent in metal manufacturing compared to other methods.

4, Higher accuracy and repeatability

Due to the heat involved in the process, the cut parts have higher precision and surface quality. In addition, the manufacturing speed increases repeatability while reducing the time spent machining the metal.