For anyone working with metallic tools, magnetism is undoubtedly one of the most important characteristics. Whether you need it in your product or not, understanding how your metallic component reacts with others is a major stipulation.
Today, brass has become one of the most popular metals in the world – including and especially for manufacturing purposes. So, it is understandable that you might want to ask, “Is brass magnetic?”
In this article, we’ll look into the brass magnetic link and explain all you need to know about its possible magnetic properties.
Is Brass a Ferromagnetic Material?
Ferromagnetic metals are among the most popular metal types as far as magnetism is concerned. These metals are known for the strength of their magnetism, which is especially prominent when they are exposed to an external magnetic field. Even after you take this magnetic field out, a ferromagnetic metal maintains its magnetization property regardless.
Essentially, these metals have their permanent magnetic moments that allow them to align with the applied magnetic field and maintain that alignment even after the field is taken out.
Ferromagnetic metals are known for their spontaneous magnetization, which occurs thanks to the parallel alignment of their magnetic moments. They also exhibit hysteresis – a phenomenon where a metal responds quite slowly when the applied magnetic field is changed. For operations like brass bending or coating, hysteresis can easily affect the outcome of your process.
Sadly, it is worth noting that brass is not a ferromagnetic metal. The most popular options in this metal class include Nickel (Ni), Iron (Fe), and Cobalt (Co).
Paramagnetic and Diamagnetic Aspects of Brass
Besides ferromagnetism, paramagnetism and diamagnetism are two other forms of magnetism that should be studied.
Generally, paramagnetic materials are those with unpaired electrons in their atoms. These electrons develop magnetic moments, thus making them pretty magnetic. When a paramagnetic material is placed within an external magnetic field, its magnetic moments – which come from the unpaired electrons – align with the entirety of the field, causing a weak attraction.
You should also keep in mind that paramagnetism is relatively weak. As such, it tends to depend on temperature interactions too. As temperatures increase, you have a weaker alignment in magnetic moments generally.
As for diamagnetic materials, you have materials where all of their electrons are paired. This essentially means that you have a net magnetic moment of exactly zero. When placed within an external magnetic field, a diamagnetic metal generates a field that moves in the opposite direction to the external field itself.
So, how does all of this relate to brass? Well, if you remember correctly, brass is composed of zinc and copper – two materials that are considered to be diamagnetic. This means that when a magnetic field is applied to brass, it will most likely generate a magnetic field that is in the opposite direction. The brass magnet force is thus pretty weak across the board.
In the case of brass, these diamagnetic properties tend to be more pronounced than the paramagnetic ones. You might notice some weak paramagnetic properties in brass thanks to the presence of impurities and trace elements, but they’re not significant enough for brass to be considered a paramagnetic material.
As such, brass is mostly considered to be diamagnetic.
Important Factors That Affect The Magnetism Of Brass
If you’re still asking, “Does brass stick to a magnet?” you pretty much have your answer. Primarily, the brass magnetic lates have a pretty weak action. So, the magnetism of brass isn’t so strong.
The major reason for this weak brass magnetic force is the material’s constituents. Brass comes with non-magnetic elements like zinc and copper, and this means that the material doesn’t do so well with magnets.
That said, there are a few other factors that could influence this brass magnetism to a small extent. Some of them include:
One of the major factors that can determine the magnetism of brass is the material’s composition itself. Manufacturers can have different material constituents for brass, and these constituents will generally dictate the properties of magnetism that you get from it.
So, is brass magnetic or not? You first need to understand how the properties of its constituent materials work. By increasing the proportion of magnetic elements like iron in a brass alloy, you will be able to considerably improve its magnetic susceptibility.
Presence of Impurities
Also related to the first point, you need to keep a close eye on foreign elements and trace impurities in your brass alloy too. All of these will influence the material’s magnetic properties, and they play a major role.
In general, even a small amount of a non-magnetic element can significantly degrade the magnetic properties of brass – which, as we pointed out, aren’t so considerable in the first place.
Processing and Heat Treatment
Another critical factor that can determine the magnetic properties of brass will have to be the processing and heat treatment techniques applied to it. For instance, heat treatment processes such as annealing can easily change the arrangement of magnetic domains and atoms within the material and affect its magnetism.
You also need to be careful with manufacturing processes such as sintering.
Like many materials, the magnetic properties of brass tend to be significantly dependent on the ambient temperature. Switches in temperature tend to affect the strength of magnetism, and in the case of materials such as brass, temperature rises tend to reduce magnetic susceptibility.
So, the answer to the question “Does brass stick to a magnet?” can depend on the temperature surrounding the material itself.
Internal Crystal Structure
Next up, we have the crystal structure of the brass material. This factor considers the arrangement of atoms in the material’s crystal lattice, as well as the alignment of magnetic moments within the material itself.
Magnetic Field Strength
Finally, keep an eye on the strength of the external magnetic field that is applied to brass. Whenever it is exposed to a considerable magnetic field, brass can show a temporary magnetic response.
As we pointed out earlier, brass isn’t particularly a strong magnetic material – mostly due to its composition. However, you can have several factors that will help to optimize or impede this magnetic factor even more. For most practical applications, however, you’d find that the magnetic functions of brass aren’t seen to be considerable.
Testing the Magnetism Of Brass
For most manufacturers, understanding how brass exhibits magnetic properties is more than a necessity. However, considering that there are so many factors that can affect the general magnetic properties of the material, you want to find ways to test if it is ideal for your functionality.
Testing Methods For Brass & Its Magnetism
So, let’s look into some of the most popular options for how to test brass and its magnetic functions.
A visual inspection is the easiest method for how to test if brass is real. You can simply tae a strong magnet and observe the attraction of the brass material to it.
In most cases, you will find a weak magnetic attraction at best. As such, keep a close eye to observe any possible action.
Magnetic Susceptibility Measurement:
You can also take instruments such as a magnetic susceptibility balance to measure brass’ magnetic susceptibility. The benefit of this instrument is that it can detect even the weakest magnetism effects – such as you’re more likely to find with brass.
Hall Effect Sensor:
A Hall effect sensor is an instrument that’s capable of detecting the presence of any magnetic field – as well as its overall strength. You can pass a sample of a brass material through the sensor with a magnetic field applied to it, and you can use that to determine any possible induced magnetism.
Vibrating Sample Magnetometer (VSM):
Like the Hall effect sensor, the Vibrating Sample Magnetometer is another sensitive tool that can easily measure magnetic properties. Even in materials where magnetism is pretty low, it does pretty well to detect the feature.
Superconducting Quantum Interference Devices (SQUIDs) are incredibly sensitive magnetometers that operate primarily for measuring magnetism in weak materials. Even the faintest levels of magnetism can be detected, and these devices work rather well across the board.
Eddy Current Testing:
The Eddy current test is a non-destructive testing method that makes use of electromagnetic induction to notice small changes in a material’s magnetic permeability and electrical conductivity. Although its use is mostly in detecting defects, an indirect benefit of the test is that it also reveals electrical properties.
Magnetic Hysteresis Measurement:
It’s one thing to ask, “Do magnets stick to brass?” Just as well, you want to examine the response of the materials to changes in magnetic fields. To do that, you can perform a hysteresis measurement. Specialized tools will be needed here, and you need to follow a thorough process. However, success with this process will help you to gain some valuable insights about the magnetic material overall.
X-ray Magnetic Circular Dichroism (XMCD):
Generally, the XMCD process is more specialized and advanced. It can help you to investigate a material’s magnetic properties, taking things at an atomic level to give you precise readings.
As you test, you want to remember that brass is a pretty weak magnetic material. So, any magnetic response you get as a result of any of these tests will be pretty subtle.
When choosing a method, consider the sensitivity required for your application as well as the availability of equipment. You can also consult us at KDM Fabrication to learn more about the right testing procedures for you.
Conducting A Simple Magnetism Test For Brass
As we explained earlier, a visual inspection is the simplest way for you to test the magnetic properties of brass in general. To that end, here’s a simple strategy to help you conduct the right test.
To run this simple test, you can easily get a few materials to make do. They include:
- A sample of brass – it could be just a small piece
- A small magnet with strong properties
- A clean, non-metallic surface – a piece of paper, a wooden table, etc.
Prepare the Brass Sample:
See to it that your brass sample is clean and doesn’t have any magnetic contaminants. The piece should also be small and easy to manage overall.
Prepare the Magnet:
Your magnet should be compact and very strong. You can use a refrigerator magnet if you can find one. As usual, ensure that it is free of any debris and completely clean.
Test for Attraction:
To test for attraction, follow these steps
- Hold the magnet above the brass sample, but be sure not to touch it.
- The magnet should be at a distance from the brass surface, then begin moving them together.
- Closely observe the behavior of the brass as they get closer to each other.
- If there is a magnetic attraction there, the brass piece will move slightly – in some cases, it could even stick to the magnet directly.
- If you don’t notice any attraction, then you might want to check if there are signs of repulsion instead.
Interpret the Results:
All in all, you can tell signs of diamagnetic impurities or elements if the brass sample gets attracted to the magnet.
Will a magnet stick to brass? Most likely. Still, you should generally expect a weak level of magnetic attraction. So, you shouldn’t expect to see much in terms of strong attraction or connection.
If there is repulsion or no attraction, then you most likely have a diamagnetic brass sample instead. You can repeat the test if you want to, just to make sure the material is set and to confirm the results of the first test you conducted.
Can Brass Be Magnetized?
Will a magnet pick up brass? We already confirmed that this happens, although the level of magnetism you get is generally low. Brass does not contain a strong intrinsic magnetic property like most ferromagnetic materials, and it also doesn’t retail a permanent magnetic field when you take out the external magnetic field.
However, you can temporarily magnetize the material with an external magnetic field if the need arises.
You see, when a brass sample is exposed to a strong magnetic field, its atomic magnetic moments will be able to easily align with the field. This causes a temporary magnetization of the brass sample – a phenomenon known to experts as induced magnetism.
It is worth noting that the level of magnetization you achieve in brass will depend on the strength of the applied magnetic field and the constituent elements in the brass alloy itself. Once you take out the external magnetic field, the brass will lose its induced magnetism and return to the original level of weak diamagnetism.
So, while brass isn’t magnetic in its natural state, you can temporarily magnetize it by using a strong external magnetic field. This will last as long as the field is present, with the material eventually losing its properties when the field is taken out.
Brass is a generally weak magnetic material. However, as we explained, there are methods to optimize that feature. To learn more, feel free to reach out to us at KDM Fabrication