The science behind metal spraying involves extreme amounts of thermal and kinetic energy. With the versatility of metal spraying, the science may be altered from one application to the next. Read on to find out more about the process of metal spraying and the different techniques used.
What Is Metal Spraying?
Metal Spraying is an engineering technology used to improve the surface properties of components. This technology is applied to a range of industries, as it has proved to be invaluable when extending component lifespan.
The most common applications of metal spraying occur in architecture, machine engineering, aerospace, and motor vehicles. This is because in these applications, substrates are exposed to extreme environmental pressures.
However, in all instances, components must be highly durable. Metal spraying is the only way to ensure components are robust and resilient.
Multiple products fall under the main categories of metal spraying- finishing coatings and surface coatings. Examples of finishing coatings are decorative or anti-corrosion, while surface coatings may be wear-resistant or thermal barrier.
The Science Behind Metal Spraying: The Process
Metal spraying requires a source of immense heat, to melt the spraying material and a projection method- usually spraying apparatus.
The spray material must be suitable for the environment and the task a component will be used in. It must also withstand the heat needed in the spraying process. Though it is called metal spraying, plastics, ceramics, and polymers can be used too.
The metal spraying process involves the projection of small, molten particles onto a clean, prepared surface. Upon reaching the surface, the particles freeze upon contact, flatten, and mechanically bond together.
Particles adhere to the surface and form a continuous coating. This then alters the surface properties of the component.
The Science Behind Metal Spraying Equipment
The science behind metal spraying in most applications requires an abundance of thermal and kinetic energy. Read on to find out different techniques to achieve these results-
Flame Spraying
The process uses an oxy-fuel flame to melt the spraying material, whether that be metal wires, powders, or ceramic rods. The now molten material is then atomised with compressed air. This creates spray steam, which can then be projected onto a substrate.
Flame spraying offers a superior finish and involves little hassle. This method can either be semi or fully autonomous.
Arc Spraying
Arc spraying uses an electric arc to melt wires, as opposed to a flame. Once the material is molten, it is again atomised with compressed air to form a spray steam, which can then be applied.
The benefits of this application include simple controls, minimal wastage, and reliable performance.
Plasma Spraying
Plasma in engineering terms is when a gas has been raised to a high enough temperature, where it then ionises and becomes electrically conductive.
In terms of plasma spray systems, the plasma is made by connecting an electrical arc between the nozzle and the electrode inside the plasma gun. When initiated, the plasma jet projects from the nozzle, along with powder particles to form a highly adherent coating.
HVOF Spraying
High Velocity Oxygen Fuel (HVOF) is a process where a fuel is mixed with oxygen and then ignited in a combustion chamber. The gases are then projected through a nozzle, where powder is introduced to the gas stream.
Like plasma spraying, powder works to soften the stream, while also striking the surface material at a high velocity. This results in an extremely dense, hard-wear coating.
The Benefits Of Metal Spraying
You should consider metal spraying for your next project, purely because of the number of benefits it provides.
- Enhanced Durability– By improving the surface quality of a component and offering a protective layer, they become more wear-resistant in high-friction environments. Metal coatings also can dissipate impact energy, making components impact-resistant in forceful applications.
- Corrosion Protection– Metal coatings can be used to form a barrier between a component and its environment, stopping corrosion and oxidation. It can also be used as a sacrificial coating, that protects surface materials through the process of galvanic corrosion.
- Improved Thermal And Electrical Properties– Metal spraying can improve the thermal insulation performance of materials, as well as the conductivity of heat and electricity. This depends on the spraying material and application.
- Repair And Refurbishment– As opposed to replacing components, which can be a costly, timely, and disruptive process, metal spraying can restore damaged surfaces and the continuing of operations.
- Versatility And Flexibility– With the wide range of materials that can be used and types of applications, metal spraying can be used across many different industries. It is highly customisable based on project requirements.
- Environmentally Sustainable– As metal spraying is an additive process, there is significantly less material wastage, making is a much more sustainable process than subtractive methods in repair and refurbishment.
The Science Behind Metal Spraying Solutions From Alphatek
We hope you now feel more familiar with the science behind metal spraying.
At Alphatek, our metal spray coatings are proprietary. With a combined experience of 100+ years, when it comes to coating solutions, you can rely on our expertise to get your desired results.
We deliver our metal spraying solutions to a range of industries, such as oil & gas, rail, paper & print, automotive, aerospace, defence, utilities & clean energy, and so much more. Our coatings are designed to meet our clients’ specific needs, so whatever your industry, we are here to help.
Contact us today to enquire about our services or find out more information on why you should consider metal spraying for your next project.
