You have lots of choices when you want a strong magnet. Think about making a guitar pickup or a cool speaker. Choosing the right material is very important. Alnico Magnets have special features that make them different. Knowing these differences helps you do your project well.
Table of Contents
Key Takeaways
Neodymium magnets are very strong permanent magnets. They work well in small devices that need lots of power.
Alnico magnets can work in high heat up to 525°C. This makes them good for use in hot places.
Alnico magnets do not rust. Neodymium magnets need a special coating to stop rust in wet areas.
When picking a magnet, think about heat, strength, and where you will use it. This helps you choose the right magnet for your project.
Alnico magnets usually cost less than neodymium magnets. This makes them a good choice if you want to save money.
Key Differences
Magnet Materials Comparison
When you pick a magnet, you want to know how it works. This magnet materials comparison shows the main ways alnico and neodymium magnets are different. You can look at the table below to see their most important features:
Feature | Alnico Magnets | Neodymium Magnets |
|---|---|---|
Magnetic Strength | Lower (Max BHmax: 5–9 MGOe, Surface: 0.1–0.2 T) | Much higher (Max BHmax: 35–52 MGOe, Surface: 0.4–0.6 T) |
Temperature Stability | Up to 525°C | Up to 150°C |
Resistance to Demagnetization | Very high | High, but varies by grade |
Corrosion Resistance | Excellent, no coating needed | Poor, needs protective coating |
Typical Applications | Motors, electronics, medical devices, speakers |
Tip: Neodymium magnets pull the strongest. Alnico magnets work better if it gets really hot or rough.
Magnetic Strength
You can see how strong each magnet is by checking the numbers. Neodymium magnets are much stronger than alnico magnets. The table below shows their maximum energy product and surface field:
Magnet Type | Max Energy Product (BHmax) | Surface Field (Tesla) |
|---|---|---|
Alnico 2 | ~5 MGOe | ~0.1 T |
Alnico 3 | ~7 MGOe | ~0.15 T |
Alnico 4 | ~8 MGOe | ~0.18 T |
Alnico 5 | ~9 MGOe | ~0.2 T |
Neo N35 | ~35 MGOe | ~0.4 T |
Neo N42 | ~42 MGOe | ~0.5 T |
Neo N52 | ~52 MGOe | ~0.6 T |
Neodymium magnets are the strongest.
Alnico magnets are not as strong as neodymium magnets.
Temperature Stability
Sometimes you need a magnet that can handle heat. Alnico magnets can work in heat up to 525°C. Neodymium magnets only work up to about 150°C. If your project gets very hot, alnico is a better pick.
Resistance to Demagnetization
Alnico magnets are very good at keeping their magnetism. They do not lose their power even with strong magnetic fields. Neodymium magnets also resist losing their magnetism, but it depends on the grade. Some grades lose strength faster than alnico.
Magnet Type | Coercivity Characteristics | Resistance to Demagnetization |
|---|---|---|
Alnico | High coercivity, can withstand extreme demagnetization forces | Superior to other permanent magnets |
Neodymium | Varies by grade, generally high coercivity | Less powerful than alnico in terms of coercivity but varies by grade |
Corrosion Resistance
You want your magnet to last a long time. Alnico magnets do not rust or corrode, so you do not need to cover them. Neodymium magnets can rust easily, especially if they get wet. Makers often add nickel, zinc, or epoxy coatings to keep them safe.
Magnet Type | Corrosion Resistance | Protective Coatings |
|---|---|---|
Alnico | No additional coatings required | |
Neodymium | Susceptible to corrosion in moist environments | Coated with nickel, zinc, or epoxy to prevent rusting |
Typical Applications
You can find alnico and neodymium magnets in many things. Here are some common uses:
Alnico Magnets:
Guitar pick-ups
Electrical motors
Sensors and meters
Aerospace parts
Equipment that gets very hot
Neodymium Magnets:
Motors and generators
Electronics and speakers
Medical devices like MRI machines
Car sensors
Science tools
Note: Pick alnico if you need a magnet for heat or tough places. Pick neodymium if you want the strongest magnet for a small space.
This magnet materials comparison helps you see which magnet is best for you. Now you can choose the right type for your project.
Alnico Magnets
Composition and Properties
Alnico magnets are special because of their mix of metals. The name alnico comes from aluminum, nickel, and cobalt. These metals work together to make alnico magnets strong. They also give alnico its unique magnetic abilities. Here is a table that shows what is inside alnico magnets:
Element | Percentage Range |
|---|---|
Aluminum (Al) | 8–12% |
Nickel (Ni) | 15–26% |
Cobalt (Co) | 5–24% |
Copper (Cu) | up to 6% |
Titanium (Ti) | up to 1% |
Iron (Fe) | remainder |
Alnico magnets keep their magnetism for a long time. They do not lose power easily, even with strong magnetic fields. Alnico can handle heat better than most other magnets. Some types work in heat up to 525°C. The table below shows how different alnico grades perform:
Material & Grade | Max. Energy Product (MGOe) | Remanence (kG) | Coercive Force (Oe) | Curie Temp. (°C) | Working Temp. (°C) | Density (g/cm³) |
|---|---|---|---|---|---|---|
Alnico 2 | 1.6 | 12.8 | 7.0 | 810 | 450 | 7.0 |
Alnico 3 | 1.2 | 10.0 | 6.0 | 810 | 450 | 6.9 |
Alnico 5 | 5.0 | 40.0 | 12.5 | 860 | 525 | 7.3 |
Alnico 5DG | 6.5 | 52.0 | 13.0 | 860 | 525 | 7.3 |
Alnico 5-7 | 7.5 | 60.0 | 13.5 | 860 | 525 | 7.3 |
Alnico 6 | 3.5 | 28.0 | 10.0 | 860 | 525 | 7.3 |
Alnico 8 | 5.0 | 40.0 | 8.0 | 860 | 550 | 7.3 |
Alnico 8HC | 4.5 | 36.0 | 7.0 | 860 | 550 | 7.3 |
Alnico 9 | 9.0 | 72.0 | 10.5 | 860 | 550 | 7.3 |
Tip: Alnico magnets stay strong, even when it gets hot or tough.
Typical Uses
Alnico magnets are used in many places because they are strong and stable. Here are some common ways people use them:
Sensors and reed switches in security alarms
Microphones and guitar pickups for classic sound
Loudspeakers that give warm audio
Lifting, holding, and separating heavy metal sheets
Heat treatment jigs in metalworking shops
Traveling wave tubes for radio signal amplifiers
Aerospace and military gear, like sensors and radar
Science kits for learning about magnets
Alnico magnets are great when you need a magnet that does not lose power. They work well in hot or rough places. You can trust alnico magnets for music, industry, and science.
Neodymium
Composition and Properties
Neodymium magnets are found in lots of modern things. They use a special mix of elements to make them strong. The main parts are:
Neodymium (Nd)
Iron (Fe)
Boron (B)
The chemical formula is Nd2Fe14B. This formula gives the magnet a special crystal shape. The shape helps the magnet focus its force in one direction. That makes neodymium magnets very strong.
Neodymium magnets keep their strength for a long time. Remanence means the magnet stays strong after you take away another magnet. Coercivity means it does not lose power easily. Neodymium magnets can reach up to 1.6 Tesla in magnetic flux density. This is much higher than most other magnets.
Here is a table that shows the properties of common neodymium magnet grades:
Material Type | Residual Flux Density (Br) | Coercive Force (Hc) | Max Energy Product (BH)max |
|---|---|---|---|
N35 | 11.7-12.1 KGs | >11.0 KOe | 33-35 MGOe |
N38 | 12.2-12.6 KGs | >11.0 KOe | 36-38 MGOe |
N40 | 12.6-12.9 KGs | >11.0 KOe | 38-40 MGOe |
N42 | 13.0-13.2 KGs | >11.0 KOe | 40-42 MGOe |
N45 | 13.3-13.7 KGs | >11.0 KOe | 43-45 MGOe |
N48 | 13.8-14.2 KGs | >11.0 KOe | 45-48 MGOe |
N50 | 14.1-14.5 KGs | >11.0 KOe | 48-50 MGOe |
N52 | 14.5-14.8 KGs | >11.2 KOe | 49.5-52 MGOe |
Tip: Neodymium magnets are the strongest for their size.
Typical Uses
Neodymium magnets are used in many things you see every day. Their strong pull makes them great for small gadgets and big machines. Here are some common uses:
Hybrid cars
Audio speakers
Electric guitar pickups
High-performance AC servo motors
Starter-generators in hybrid and electric cars
MRI machines
Permanent magnet motors in cordless tools
Vacuum cleaners and other motorized home appliances
Wind turbine generators
Mobile phones
Headphones
Speakers
Neodymium magnets help headphones and speakers sound clear. They make electric cars work better and help wind turbines make clean energy. You also find neodymium magnets in MRI machines. When you use a phone or computer, neodymium magnets help keep your data safe.
Note: If you want a small magnet with lots of power, neodymium is the best pick.
Comparison Between Magnetic Materials
Magnetic Strength and Cost
It is important to know how strong a magnet is. Neodymium magnets are the strongest permanent magnets you can get. Even a small neodymium magnet gives a lot of force. Alnico magnets are not as strong, but they still work in many places.
When you look at price, there is a big difference. Alnico magnets usually cost less than neodymium magnets. This is true if you compare magnets that are the same size and strength. If you want to save money on your project, alnico is a good choice. Neodymium magnets cost more because they use rare earth metals and need special steps to make.
Magnet Type | Magnetic Strength | Cost per Unit Strength | Typical Cost per Kilogram |
|---|---|---|---|
Alnico | Lower | Lower | Lower |
Neodymium | Highest | Higher | Higher |
Tip: Pick neodymium if you need the strongest magnet in a small space. Pick alnico if you want to save money and still get good strength.
Temperature and Environment
Magnets can change when the temperature changes. You should think about where you will use your magnet. Alnico magnets keep their power even when it gets very hot. They can work in places up to 900 °C. Neodymium magnets lose power when they get hot. Most neodymium magnets work up to 80 °C, but some special ones can go up to 200 °C.
Here is a table that shows how each magnet works at different temperatures:
Magnet Type | Maximum Operating Temperature | Low Temperature Performance |
|---|---|---|
Alnico | 450-900 °C | Down to -70 °C |
Neodymium | Up to 200 °C | Down to -138 °C |
Alnico magnets are very stable when it is hot. They do not lose power from heat as much as neodymium magnets. Neodymium magnets stay strong in very cold places, so you can use them in the cold.
Other things in the environment matter too. You should think about water, bumps, and strong magnetic fields. Neodymium magnets can rust if they get wet, so they need a special coating. Alnico magnets do not rust and do not need extra protection.
Temperature: Neodymium magnets lose power if they get too hot.
Corrosion: Water can make neodymium magnets rust. Alnico magnets do not rust.
Mechanical Stress: Both types are easy to chip or crack if dropped.
External Magnetic Fields: Strong fields can make magnets lose power.
Aging: Over time, magnets can get weaker from the environment.
Note: The outside of the magnet is important for how long it lasts. Neodymium magnets need coatings like nickel or epoxy to stop rust. Coatings help magnets work better in tough places.
Durability
You want your magnet to last a long time. How long it lasts depends on how strong it is, how easy it is to break, and how well it resists damage. Both alnico and neodymium magnets can break if you drop them.
Magnet Type | Brittleness | Mechanical Strength |
|---|---|---|
Alnico | Brittle | Good |
Neodymium | Brittle | Strongest |
Alnico magnets are strong, but they can still chip. Neodymium magnets are the strongest, but they are also easy to break. You should be careful with both types.
Magnets can fail in different ways, like rust, heat, breaking, getting weaker over time, or problems from how they are made. Neodymium magnets can rust in wet places, which makes them lose power. High heat can make both types weaker, but alnico does better with heat.
Failure Mode | Description |
|---|---|
Corrosion and oxidation failure | Neodymium magnets can rust in wet places and lose power. |
Thermal degradation | High heat can make magnets lose power and not work as well. |
Mechanical failure | Both types can break or crack if hit or dropped. |
Aging and long-term degradation | Magnets can get weaker over time from heat and the environment. |
Manufacturing defects | Problems in how magnets are made can make them fail early. |
The outside of the magnet also matters for how long it lasts. The texture affects how well the magnet keeps its power and direction. A strong texture helps the magnet stay strong even with other magnets nearby. Coatings and treatments help magnets last longer in tough places.
Tip: Always check the outside and coating of a magnet before using it in a hard place.
You can use this comparison to help you pick the right magnet. Think about how strong it is, how much it costs, how it handles heat, and how long it will last. Each magnet is best for different jobs.
Choosing a Magnet
Picking the right magnet for your project is important. It can change how well your project works and how much it costs. You should think about where you will use the magnet and what it needs to do. Each magnet type has good and bad points. These points affect how you use the magnet and how long it lasts.
First, ask yourself what you need most. Do you want a magnet with very strong pull? Or do you need one that works in high heat? Here are some things to think about:
Factor | Description |
|---|---|
Maximum Operating Temperature | Magnets act differently in heat. Alnico magnets work in hot places. Neodymium magnets lose power if they get too hot. |
Demagnetizing Resistance | Alnico magnets keep their power, even with strong fields. Neodymium magnets can lose strength faster, especially when hot. |
Corrosion Resistance | Alnico magnets do not rust, so you can use them in wet places. Neodymium magnets need coatings to stop rust. |
Cost | Alnico magnets cost less for many jobs. Neodymium magnets cost more but are stronger in small sizes. |
Tip: Pick alnico magnets if you need them for hot places. Neodymium magnets are best for small spaces with strong pull.
People make mistakes when they forget about heat limits. Neodymium magnets are strong, but they cannot handle high heat. Alnico magnets are better for hot places. If you go past the heat limit, the magnet can lose its power forever.
Think about your budget and the shape you want. Alnico magnets are cheaper and easy to find. Neodymium magnets cost more, but they are stronger and can be made in special shapes.
Use alnico magnets for sensors, guitar pickups, and things that get hot.
Pick neodymium magnets for electronics, motors, and things that need strong pull.
Always check the place and temperature before you choose your magnet.
Your choice changes how well your project works, how long it lasts, and how much it costs. Pick the magnet that fits your needs for the best results.
You can remember the main differences like this:
Neodymium magnets are much stronger and work well in small spaces.
Alnico magnets can take high heat and do not rust, so they are good for tough places.
Neodymium is best for things like electronics, motors, and speakers. Alnico works well for sensors, things used in water, and places with heat or wetness.
Before picking a magnet, think about what your project needs. Check the temperature it will face. Think about where you will use it. Make sure it fits the space you have. Think about how you will put it together. Decide if you need a coating to protect it.
FAQ
What makes alnico magnets better for high-temperature application?
Alnico magnets work well in hot places. They keep their strength up to 525°C. This helps when your project gets hot, like in motors or sensors.
Why do neodymium magnets need a coating for some application?
Neodymium magnets need a coating if there is moisture. The coating stops rust from forming. In wet or humid places, the coating helps the magnet last longer.
Can you use neodymium magnets for medical application?
Neodymium magnets are used in medical devices. They work in MRI machines and sensors. Their strong pull is good for small devices. Always check safety rules before using them in medical equipment.
Which magnet is best for audio application?
Neodymium magnets are great for small speakers with strong sound. Alnico magnets are good for classic guitar pickups and microphones. Pick the magnet based on the sound and size you want.
How do you choose the right magnet for your application?
Look at the temperature, strength, and where you will use it. Alnico magnets are good for hot or rough places. Neodymium magnets fit small spaces and pull strongly. Think about cost and protection before you choose.