Sometimes we cover things specific to home improvement, and other times it’s more focused on commercial construction.
The topic of conductive materials is one we get asked about and know our readers want.
In this article, we’ll cover some of the materials that we didn’t get to cover the first time around. It includes things such as thermal paste, plastic, and tungsten.
We previously covered some of the bigger ones, like aluminum and gold. Now it’s time to cover the more obscure materials.
Why do some materials conduct electricity and others don’t?
To understand conductivity, you need to understand electrons. It essentially comes down to their free electrons. Materials such as rubber and wood aren’t great conductors, and these insulators oppose the transfer of current.
It’s a reason why you’ll have better protection by wearing rubber gloves than you will if you’re wearing wooden gloves. Rubber is a better insulator than wood is.
Metals always conduct electricity, but some are significantly better than others. Copper and aluminum are both widely available without costing too much and are good at transferring energy.
On the other hand, silver is even better than copper. However, it’s not available in nearly the same quantities and isn’t as extensively used as copper is.
At the same time, gold lands somewhere in the middle between aluminum and copper in terms of transporting electricity. However, there isn’t a lot of it, and it is rarely used for that reason.
We’ll reintroduce a standard that we talked about in the previous article.
Material IACS (International Annealed Copper Standard)
With the IACS rating, it’s possible to get an understanding of how conductive material is. With copper being 100%, other materials are measured compared to it. Another material is only ⅕ as conductive if it has a score of 20%.
It makes it easier to compare but also understand the topic.
Let’s get on and look at some of the materials you guys have requested more information on, including duct tape and titanium.
Factors that affect the electrical conductivity
How well a material conducts electricity is determined by various factors. Here’s a brief summary of them so you can better understand them.
- Frequency: The number of oscillation cycles will affect it. Alternating current will complete a set amount of these per second. When the number is too high, the skin effect can occur. It causes current to flow around a conductor. It’s not a thing that will happen with the direct current because it has no frequency caused by the oscillation.
- Electromagnetic fields: Electromagnetic fields are generated around conductors when current is transferred through them. The magnetic field is perpendicular to the electric field. External electromagnetic fields can slow the flow of current. It happens because they produce magnetoresistance that interferes with the flow of the current.
- Phases and crystal structures: Different structures and materials will have different conductivity. Different phases of material will have the same effect. As a consequence, the current is slowed at the interface.
- Impurities: Impurities generally decrease the conductivity of the material. It’s not the case with water, where the conductivity depends on the impurities. For silver, pure silver is a better conductor than sterling silver. Electron flow is affected when impurities are added to metals.
- Temperature: Metals usually transfer current worse under warm conditions than they do under somewhat colder conditions. It’s the case with silver and copper. When you’re finding the right copper wire, you will need to know the ambient temperature rating of the setting. It will influence the gauge of the wire you’re able to use. When the temperature increases, thermal excitation happens to the atoms. Resistivity goes up, and the material becomes less able to transfer current. The relationship will not work at a certain point for low temperatures.
Thermal paste can help remove heat from a processor chip, but it’s electrically insulating. Processor chips will often only work in a specific temperature range, so this paste will help ensure their longevity and proper functioning.
It is put so that air gaps are removed, and heat is transferred away from the microchip.
Plastic is like rubber and other non-metal materials. They share the feature that they act as insulators and are not conductive, plastic included.
It’s not to say that it can’t transfer electricity at all, but the conditions required for it to do so are generally not there. With a sufficiently high voltage, most materials are capable of transferring electricity. It can just be a matter of the right circumstances.
It is also not to say that it cannot be made to be conductive. The situation is a bit more complicated because there are metals with very low IACS ratings and others with higher ones. By making mixed products, you can also mix their properties.
In turn, if you mix something very conductive with plastic, you can get new material out of it with different properties.
Tungsten is a rare metal found naturally and was first discovered in 1781. We’re happy it was discovered because it now serves as field emitters, electrodes, and a range of other purposes. It is even mixed to form a wear-resistant coating because of its various properties. These are called superalloys.
It is very hard to melt and very dense, creating certain challenges when working with it. Its density makes it durable and strong, with an extremely high melting point.
We owe a lot of the development in modern integrated circuitry to the discovery of tungsten. Microelectronic devices rely on the ability to remove heat for proper functioning, and that’s where tungsten comes into the picture.
The IACS rating for tungsten is 31.40%, making it a lot more conductive than many other metals. Its high plasticity and evaporation rate present opportunities unmatched by most other metals.
Yes, silicone is conductive and gets better at it as the temperature rises. On the other hand, higher temperatures will have the opposite effect on metals. However, pure silicon is closer to being an insulator.
Did you know silicon’s natural state is a hard, solid grey matter?
As it’s a semiconductor, silicon has a lot of uses. Under some conditions, it transfers electricity. However, it becomes an insulator when those conditions aren’t there.
Solar panels and processor chips are examples of where you will find this material. Another great thing about silicon is how abundant it is.
You’ve probably seen that it is also used for a myriad of things outside the built world. For instance, you can get silicone utensils used in the kitchen. Imagine how much they would cost if they were made of gold instead.
Also, a semiconductor can act as both a conductor and an insulator. As the temperature decreases, the number of free electrons does the same. Without the free electrons, electricity is not able to pass.
Molecular vibrations start happening more as the temperature rises, and the free electrons turn it away from mainly being an insulator.
At high-enough voltage, duct tape is conductive. It also depends on how it’s made. The original duct tape was aluminum foil with adhesive on it.
If you read the other article, you will know that aluminum is very good at transferring electricity. It’s why it’s so commonly used inside wire and electrical cords.
However, newer duct tape is made a bit different. Some of it is made entirely of plastic, which makes it significantly less conductive. If duct tape is used as an insulator, it’s best to replace it with something better intended for the purpose.
Some people have used duct tape as an insulator, and that is not its intended use. When you’re working with electricity, it’s important to take precautions.
Only use the intended products for their intended uses.
Titanium is not a good conductor of electricity and has an IACS rating of 3.10%. It means copper is roughly 32 times as efficient at the purpose as titanium.
It’s very poor for heat and electrical transfer, so it may only be used in certain places. However, the aerospace and medical industry are places where titanium is being used. It can also be found in some electronic circuits.
Ice is not a good electrical conductor. It’s not even as good as water is.
In water, it’s the impurities that give it its conductive traits. Without the impurities, it would have none of them. However, the temperature differences between ice and water will slow the flow of charged particles. Dissolved salt has charge carriers, but those particles are treated differently in ice than in water. In ice, they’re shoved out of the ice crystal. They have very little possibility of moving.
Without enough energy for the ions to hop from place to place, the electricity has difficulty moving around. Mobile and charged particles are required for the process to happen. These ions can be either negative or positive.
Zinc is electrically conductive, with an IACS score of 27%. Compared to copper, it may not look so. When comparing it to a range of different metals, it’s moderately good when transferring energy.
However, chromates are often applied to zinc. These chromates are typically not conducive.
Zinc is now being used for various purposes when it comes to electronics. For instance, you will find it in some air rechargeable batteries and nano-lasers.
However, its most common use is in galvanizing other metals. It’s done so that the elements won’t get to them, and rusting is minimized on surfaces like safety barriers and cars.
It’s important to know that there are different types of solders, and none of them are as conductive as copper is. Soft solders have IACS scores that range between 9 to 13 percent of copper’s score. However, soft solders include silver components that give them an IACS score ranging between 20 to 40% of silver’s score.
Hot glue is usually made up of low-density polyethylene. As a non-metal, its electrical conductive properties are limited. However, it changes over time as it absorbs more moisture.
As with anything else, there are circumstances when the current will flow through it. An example could be if there’s a high voltage passing through. Therefore, it is not recommended for high-voltage applications as you’d be better off with a better insulator.
Oils are usually good insulators, meaning the oil isn’t very conductive. Additives, base oil, and polarity can change it. These can be added on top of engine parts such as transformers or switches to protect against corrosion.
Isopropyl alcohol is generally considered not to be conductive and is more so considered an insulator. Although all things can transfer current, isopropyl alcohol is not high on the list of things that do it very well.
Diamonds are known as electrical insulators because they do not conduct electricity well. However, when it comes to heat, it’s a different story.
Diamonds can be altered with CVD, whereby they can become capable of conducting electricity. However, it’s a significant process.
Pure silver is the most conductive metal, but it has some issues that make it unfit for typical electrical purposes. It can tarnish, and it’s expensive. Despite being better at transporting electricity than copper, the downsides do not make it a better medium for the purpose.
It’s so good that it beats copper by 5%, despite the IACS being based on copper. However, it would not be a practical material for large-scale electrical purposes.
Lead has an IACS score of 8.40%. It means it’s moderately good at moving current, but that copper is still almost 12 times as good. At the same time, aluminum is roughly 7 times as good. Lead’s relatively high IACS score means it’s a bad insulator for that reason.
Its IACS score allows it to be used as an anode material, but it doesn’t mean you’d want to use it for purposes requiring the move of big amounts of electricity.
Hopefully, this has helped shed some light on whether or not a material you were thinking about is a good insulator. It’s an important consideration depending on the situation you’re planning to use the material.