Heat treatment technology is used in a great variety of industries, including the pharmaceutical industry, food and beverage industry, automotive industry, and the chemical industry. It is also a common practice in manufacturing to coat or treat heat-sensitive materials to prevent them from becoming overheated during processing. Heat treatment involves magnetic heat, also spraying, dipping, or coating heat-sensitive materials with an alloy that has properties that make it less likely to become pyrophoric (a burnable material). This process limits the amount of energy that can be released when the material undergoes greater amounts of heating. The resulting product does not oxidize as quickly as uncoated counterparts, which makes it more resistant to oxidation. In most cases, heat-treated products are more durable than their counterparts that do not undergo heat treatment. However, this does not mean that all heat-treated materials have equal benefits. In order to effectively choose the right product for your project, you should understand how these chemicals work and what kind of applications they are suited for.
What is a Magnetic Nanoparticle?
A magnetic nanoparticle is a tiny magnetic metal oxide (i.e. magnetite, Fe2O3) or metal sulfide (i.e. ferrimetalum, FeS) that is coated on one or both sides with superparamagnetic iron oxide or superparamagnetic iron sulfide. Basically, a magnetic nanoparticle is an iron oxide or iron sulfide that is coated with a magnetic material. Typically, the coating is made of iron oxide (FeO) or iron sulfide (FeS). However, other magnetic materials can also be used, depending on the application. The combination of superparamagnetic iron oxide or iron sulfide and a low surface-area magnetic metal makes a nanoparticle that is highly attractive for sensors, actuators, and other applications.
How Magnetic Nanoparticles Work?
When a magnetic field is applied to a surface covered with a magnetic material (such as a bar or wire), it causes the grains to align in a specific orientation. This force is then mediated by a superparamagnetic material that is contained in the nanoparticle. When a material is situated between two perpendicular magnetic fields, it becomes paramagnetic — a property that makes it highly attractive as a Near-Field Magnetron Trap (NFMT) material. An NFMT material can be used to sense the presence of magnetic fields or to generate magnetic fields by resonant emission of electromagnetic waves. The properties of the superparamagnetic material enhance the effect of the magnetic fields to produce very high specific heats and high rates of corrosion. As a result, superparamagnetic materials are used in a variety of applications to reduce the risk of Maintaining Leaks and Spills. A superparamagnetic material is very dense, meaning that there is very little energy released when the material is heated.
Heat Treatment with Magnetic Nanoparticles
When a material is exposed to a high-intensity heat source, it is possible to damage or destroy the material by causing it to become pyrophoric. When the heat source is a heat treatment technique, however, the damage caused by the heat can be limited. By heating the material to a high temperature, then rapidly cooling it to room temperature, the pyroism that causes damage can be prevented. This process is called thermal processing and is used to make certain materials more durable. One common thermal processing method is to heat a material to a high temperature and then quickly cool it to room temperature. Another thermal processing method is to heat a material to very high temperatures and then to slowly cool it to a lower temperature. The drawback of these two processes is that they produce a much more intense heat than is needed to make the material resistant to oxidation. In contrast, the advanced heat treatment technology called Melting Point Control (MPC) can be used to precisely control the amount of heat generated during heating and cooling to make the material resistant to oxidation. The temperature of the material is controlled to a range of 80–300°C to prevent the material from becoming pyrophoric.
Examples of Magnetic Nanoparticles in Use
Magnetic nanoparticles are gaining popularity as an additive to improve the durability of metals, composites, and other materials. Traditionally, this was done by spraying the coating into a pattern, but now it is done by printing or dipping the material in the coating. Some of the most popular uses for magnetic nanoparticles include bulletproof materials, beer bottles, and medical devices.
Benefits of Heat Treating with Magnetic nanoparticles
Why treat materials with magnetic nanoparticles? Why not just use them as inert materials? The main reason is that the superparamagnetic iron oxide (i.e. magnetite) and iron sulfide (i.e. ferrimetalum) that are the components of the nanoparticles are significantly more attractive than the base metal. As a result, the amount of heat generated by melting or burning the material is significantly reduced. Besides, the corrosion properties of the iron oxide (i.e. rusting) and iron sulfide (i.e. souring) are also significantly reduced compared to uncoated counterparts. Nowadays, most materials that need to be treated with high-intensity magnetic fields do not reach a high enough temperature to become superparamagnetic. In these cases, the high-intensity magnetism generated by MPC is enough to treat the material.
In order to effectively choose the right product for your project, you should understand how these chemicals work and what kind of applications they are suited for. Some of the most popular uses of magnetic nanoparticles are in bulletproof materials, beer bottles, and medical devices.