One of the frequently asked questions from our readers is: can a plasma cutter cut aluminum? Well, plasma cutting machines have come a long way since the late 1990s, which is the period many people think of when referencing plasma cutters.
Plasma cutters now have the latest technology that easily allows them to cut through any type of conductive metal.
Can a plasma cutter cut aluminum? Aluminum falls into the category of being a conductive metal and, therefore, is easily cut by a plasma cutter if it’s less than six inches thick. Plasma cutters can cut through most conductive metals, but it becomes harder the thicker the metal is.
Many people fail to realize how far plasma cutting technology has progressed in the past decade alone. This plasma cutting guide of sorts will give you knowledge of how plasma cutters work and their potential applications, which can save you lots of money and time when conducting projects.
How Plasma Cutter Cuts Aluminum
Plasma cutters cut aluminum, along with other conductive metals, by using a concentrated stream of ionized gasses. Common types of metals plasma cutters can cut through include:
- Mild Steel
- Stainless Steel
- Cast Iron
- Other types of metal alloys
Plasma cutting works by using ionized gasses. The ionized gas has more protons or positive ions than it usually would in nature, making it super-heated. It changes into another state of matter called plasma.
It is the interaction between the plasma protons and the metal that allows plasma to cut through conductive metals.
The protons are attracted to the conductive metal, which has a slightly positive charge, much like the opposing poles of a magnet. When the plasma gas comes into contact with the metal, the electrons from the plasma are transferred to the metal.
Being in an ionized state means that the electrons can freely move between the atoms of the gas and to the metal. The transfer of these electrons creates heat energy and essentially melts the metal that it comes in contact with. The melting of the metal creates a clean, uniform cut through the metal.
Plasma Cutting Basics
The basics of plasma cutting are essential to know if you want to experience the money and time-saving process that is plasma cutting. Other than the exact plasma cutting science previously mentioned, you must also understand a few more things about the plasma cutting process.
The two gases which are used in Plasma Cutting are oxygen and Nitrogen. Both of which have to be almost 100% pure, or at minimum 99.5% pure for oxygen and 99.995% pure for Nitrogen. The consequences of using any less purity gas than recommended are:
- that the arc losses its ability to cut through metal at any current level.
- that the arc develops variation in the cut quality.
- that the electrode that ionizes the particles is considerably shortened.
- that when cutting with Nitrogen, a black film appears on the electrode and in the nozzle.
A process called gas swirling is utilized in many plasma cutting machines because of the benefits that it provides in the process. The process works by using the fact that only 30% of the gas is ionized, leaving 70% of the gas non-ionized.
The non-ionized gas is significantly cooler in temperature compared to the ionized particles. The machine swirls the gas to allow the mixture of the ionized and non-ionized particles.
The non-ionized particles act as a temperature barrier to protect the copper alloy nozzle from melting.
Learn More About Plasma Arc Machining – PAM – Here, you can find an article from our website about: The Advantages and Limitations of Plasma Arc Machining?
The non-ionized particles also serve another purpose that is necessary for the clean, precise cut of the plasma cutter. The non-ionized particles blow away all the molten metal from the cutting area.
This allows the plasma arc to keep in constant, even contact with the metal surface without anything getting in the way.
The swirling of the gas evenly spreads the ionized particles all the way through the arc. The benefit of which allows for a tremendously even cut all the way through your cutting piece.
Overall, the breakthrough of utilizing the concept of swirling the gas gives numerous benefits that were not previously seen in the early ages of plasma cutting.
The nozzle of the plasma cutter is a vital part of the plasma cutting system. It concentrates the plasma arc cutting stream, much like the nozzle on a water cutting system. The nozzle is responsible for the size, power, and angle of the cut you make.
The nozzles are typically made of a copper alloy because of its heat retention properties and electrical conductivity properties. The copper nozzles are protected from the majority of the heat created by the plasma arc by a process called gas swirling.
The gas used for plasma cutting is not fully ionized. In optimal conditions, roughly 30% of the gas is ionized, leaving 70% of the gas in a non-plasma state, as mentioned before.
There are many types of nozzles you can use on your plasma cutter that have a range of orifices. The size of the hole is vitally important because it is what determines the size and the voltage of your arc. The smaller the hole, the larger the arc and voltage are.
You would want a smaller orifice when you are cutting:
- tougher metals
- thicker metals
- Less conductive metals
The higher the voltage, the higher the temperature the nozzle is subjected to by the ionized gas particles. Each nozzle has a maximum temperature it can withstand on the packaging of the nozzle.
If you exceed the maximum temperature, your nozzle can melt, or it significantly reduces the lifespan of your nozzle.
Benefits of Plasma Cutting
There are many benefits of plasma cutting over any other form of cutting, especially in today’s time.
When people rule out plasma cutting for projects, they are commonly stuck in the mindset of the 1980s to the 1990’s age of plasma cutting, which was barbaric when compared to the technology of today.
Plasma cutting technologies have been able to increase the ability from plasma to be able to cut through an inch of metal to now being able to cut up to six inches of metal relatively quickly.
The development of swirling the gas and others has led to being able to increase the current levels and arc size of the plasma cutter significantly.
Another form of cutting metal is oxy-cutting, which has a minimal amount of metals it can cut. Oxy-cutting can only cut through metals that oxidize, which severely limits the metals it can cut.
The technological breakthroughs that have been occurring with plasma cutting have made the ability to use the cutting platform cheaper, more cost-effective, and faster.
The Future of Plasma Cutting
The future of plasma cutting will, undoubtedly, be bright. The recent technological advancements have widely been focused on the accessibility of plasma cutting platforms.
Recent innovations in the ability to control the power and size of the arc have led to plasma cutting being used for more complex cutting projects.
The technology advancements also have led to better accuracy when cutting and a more uniform cut through the metal not seen in the early days of plasma cutting.
The next step, which is already taken hold in the plasma cutting industry, is automation and bringing that automation out of purely industrial areas to the average person who uses plasma cutting systems.
This process involves making the parts of the machines last for more extended periods and the reduction of the price of these parts.
The process of using plasma cutting has undeniable benefits compared to other ways of cutting through metal and is no longer tainted by the early, barbaric, plasma cutting platforms.
Plasma Cutter Cutting Aluminum >> Tutorial video