What is Laser Cutting?
Published: 2021-12-21 09:41:18

Laser cutting uses lasers to cut material. Laser cutting is a popular hobby tool that is widely used in industry. This blog will explain what laser cutting is and the different types.

**Laser cutting**: The rapid growth in technology and computers has led to many innovations in the manufacturing sector.

The CNC Machining process is one of these remarkable achievements.

It has enabled industries to create high-precision parts from metal for engineering development.

We will be discussing the basics of Laser Cutting, which is another type of CNC machining.

Laser cutting is not just used to cut metal sheets, but can also be used for other materials such as rubber and clothes.

The LASER beam is a great tool for cutting metal. These benefits will be discussed later in the article.

It is a popular manufacturing process. Understanding it will be a great help.

Before we discuss how a laser beam cuts the metals, let's first understand " What is LASER?"

## **What's LASER?**
Laser is for Light Amplification using Stimulated Emission Of Radiation.

This LASER technology can create a narrow beam that can be used to lighten various objects.

You should not consider LASER to be a common light source, as generic light sources can produce light with different wavelengths.

Let me explain,

Light is a wave.

Each wave has its wavelength. Different colours also have different wavelengths.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/50qimp6o0nibpes6dlml.png)

## **Generic Light Sources**

Different colours can be found in light from generic (bulb and flashlight) sources.

This means that a light source can be made up of waves.

These waves cause the light from a flashlight or bulb to appear to scatter in various directions due to their different wavelengths.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/jvrf3y4bte9ua0d1beq1.png)

**LASER is a light source**

A LASER is unique in that it contains a single colour.

This light is a single-colour, and consists only of one wave (the wavelength).

The LASER beam can be made more intense and narrower by packing multiple waves of one colour in one direction.

In the next section, you will see how the intense source of light [LASER] can be used to cut the materials.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/4da658i5v45hyv0dvygb.PNG)

## **What is LASER cutting?**

Laser cutting refers to the focus of electrical energy of a certain spot with a few kilowatts.

The high-energy heat can melt, partially vaporize and heat the material it hits.

CNS is used in laser cutting to direct a high power LASER beam to cut metals (or other materials).

Let's begin with the basics.

A resonator is generally used to produce a powerful laser beam.

There are many types of laser generators.

1. CO2 Laser
2. Neodymium Yttrium-Aluminum-Garnet (Nd:YAG) Laser
3. Fibre Lasers

## **Step 1 - Generating the Laser Beam**

Because of their affordability and accuracy, CO2 lasers are extremely popular.

It can also cut non-metallic materials and thin sheets of aluminum or non-ferrous metals.

The tube contains a mixture carbon dioxide, nitrogen, hydrogen and helium. It then produces laser light by passing electricity through it. One mirror is located at each end of the tube; one is fully reflective, the other partial.

The wavelength of the CO2 laser generated light [laser] is in the infrared, so it cannot be seen with the naked eye.


## **Step 2 - Narrowing the Laser Beam**

The laser is then passed through two specially designed mirrors before hitting the material.

This mirror serves the purpose of intensifying and narrowing the laser beam.

E.g., a laser resonator emits coherent light with a diameter between 1.5 and 2 mm. The mirror allows the laser beam to be intensified to a diameter of 0.025mm.

The laser beam doesn't focus directly on the material. However, the beam is narrowed before it passes through a nozzle and hits the material.

These mirrors function in the same way as a magnifying lens that focuses sunlight rays on paper.

Depending on the metal to be cut, we can adjust laser beam intensity, length, heat output, and so forth.


## **Step 3 - Cutting the Material**
This high-intensity laser beam is used to create a kerf at the material's edge before you begin cutting.

Sidenote Kerf refers to the material that the laser removes while cutting, or the width of the cut.

To maintain distance between the material and the nozzle, a capacitive height control system can be used.

After the kerf has been formed, the laser beam follows the G-code to trace and identify the material.

G-code refers to the digital instructions that are given by computers to the CNC machine (Laser Cutting Machine).

Today's software is capable of converting 3D models into G-code, unlike the days when engineers had to manually write G-Codes.


## **Alternatives to Laser Cutting**

Laser cutting is very popular and offers many benefits. However, there are also limitations.

Elevator consumption is high
You can't cut thick material
The type of material determines the time needed to cut material.
More
People look for alternatives to laser cutting because of the above disadvantages.

Let's have a quick discussion.

## **1 Milling**

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/33ofgwz1oo5ht1fznqc6.PNG)

The oldest and most widely used machining process in manufacturing is milling.

To remove undesirable materials, this process employs multi-sharp instruments, also known to be called milling cutters.

Multiple cutting points are used to trim excess material from a milling cutter.

To rotate a rotary milling cutter, it is mounted on a spindle.

A fixture, which is a part of the milling machine, is used to secure the workpiece. The milling cutter moves towards the workpiece using CNC.

The process of milling can be used to create holes, slots, pockets, and contours in symmetric shapes.


Milling Process: Disadvantages

To operate correctly, it takes skilled workers
Radial cuts cannot be cut
Temperature and thermal stress risk

## **2 Wire EDM**


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/nkk7ko8kwxtu5l7pmz8e.PNG)

Wire EDM stands to wire electric discharge machining.

Wire EDM uses a thin, single-stranded metal wire to cut the workpiece using heat from an electric spark.

This process is also known by the name spark machining.

The wire strand is not allowed to touch the workpiece during this process. The desired voltage is maintained on the metal wire. The wire is enclosed by de-ionized, or dielectric water.

Once the voltage is at the desired level, a spark will be generated between the wire and the respective workpiece area. This causes the workpiece to melt down.

Wire EDM is used to create small pieces and complex shapes that need a high-quality surface finish.


**The Disadvantages Of Wire EDM**

Cutting takes a long time.
Non-conductive materials cannot be cut
Temperature and thermal stress risk

## **3 Punch Press**

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/kj90c3cif821xi8amdyu.PNG)
The Punch Press is used to cut sheets of metals using pressure.

It generally consists of a punch or a die. Between these two pieces is the workpiece.

The punch is applied to the workpiece. It then undergoes the forming, bending and drawing.

Punch Press is controlled by electric motors. The rotational energy of the motors is converted to a reciprocating ram. The machine's reciprocating ram drives the punch and puts very high pressure on the workpiece.


## **Advantages of Punch Press**

Produces a very loud sound
Experts are required to install and maintain.
Small-scale production is not possible
Temperature and thermal stress risk

## **4 Water Jet**


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/9awmdd6vexh474ofmynl.PNG)

Another great invention in the manufacturing sector is Water Jet.

It produces a high-pressure jet that can cut almost all materials by using water or abrasive.

The pressure created by the jet of water is extremely high at 6000 bar. This is equal to 1000 m/s.

To convert water from a high pressure pump to a high speed, high density and ultra high pressure water jet, a costly (sintered Boride or tungsten Caride) nozzle will be used.

It is used extensively in the aerospace and mining industries for many years.

The water jet drew the final design and it has a very smooth finish.

## **The Disadvantages Of Water Jet**

1. It is very expensive to run.
2. It uses a lot of abrasive, which can be costly.

## **The Advantages of Laser Cutting**
LASER Cutting has many advantages over other processes in the industry.

Here's the complete list.

1. High precision
2. The speed of cutting is comparatively fast
3. No cleaning (smoothing), of the final product required
4. Low running cost
5. No thermal stress or temperature risk
6. This is a non-contact type of cutting (there's no contact between the laser cutter and the workpiece).
7. The Heat Affected Zone is very small
8. No damage to the workpiece
9. More safe than similar cutting processes
10. Works with many materials, including metal sheets, wood, paper and plastic.
11. Laser cutting can also be found in the medical, food and beverage industries

## **Material for Laser Cutting**
Let's talk about what materials can be cut with a laser cutter.

Laser cutters can be used to cut a variety of materials, including metals and nonmetals.

#**#1 – Metals**

1. Mild Steel
2. Aluminium
3. Stainless Steel
4. Non-ferrous metals

#**#2 - Non-Metals**

1. Wood
2. Paper
3. Glass
4. Acrylic
5. Diamonds
6. PMMA (Poly Methyl Methacrylate).
7. POM (Polyoxymethylene).

## **Materials are not suitable for laser cutting**
Here's a list of materials we can't cut with LASER Cutting.

1. PVC (Polyvinyl Chloride).
2. Fibre Glass
3. ABS (Acrylonitrile Butadiene Styrene)
4. Polycarbonate
5. Polypropylene Foam
6. Polystyrene Foam
7. HDPE (High Density Polyethylene).
8. Coated Carbon Fibre