Thermal spray aluminium coating processes in the protection

Thermal spray aluminium coating is a material surface treatment technology that is widely used in many industries. The coating process has also improved a lot over the years.

Thermal spray aluminium coating - Concept and application in industry

Thermal spray aluminium coating is a method used to restore and resurface metallic or non-metallic materials. The mechanism of action of this method is to use high-energy matter to heat some or all of a solid material in the form of powder, wire, rod or drug core. The material will be dispersed into small mist-like particles and using a specialized device to coat the surface of the part that needs to be restored.

Thermal spray aluminium coating produces a coating that is approximately 20 micrometers to several millimeters thick and can be applied in a variety of thicknesses, depending on the process and material. This method can be applied to a variety of materials such as steel, alloys, ceramics, plastics or composites.

This process is mainly applied to the surface coating of various materials, in order to restore, protect and enhance resistance to abrasion and corrosion. At the same time, coatings are also used to provide conductivity or electrical insulation, lubrication, high or low friction, sacrificial wear, chemical resistance and many other desirable surface properties. Thermal coatings also have many other useful applications such as protecting aircraft, buildings and other structures from extreme temperatures, chemicals or environmental conditions such as high humidity and rain.

Read more: Thermal Spray Aluminum and Industrial applications of Thermal Spraying Technology

Classification of thermal spray aluminium coating processes in modern industry

Thermal spray coating is used in many different industries with useful applications. Here are the 4 most common processes today to create thermal spray coatings:

Thermal spray aluminium coating - Flame Spray method

Flame Spray is the most common method and has been used widely for more than 100 years. In this process is also divided into 2 other types: wire spraying and powder spraying.

The process of thermal spraying with a gas flame uses an oxy-acetylene flame. The heat from the flame melts the coating material and the compressed air pushes it onto the surface of the material to be coated.

Read more: Thermal spray aluminium coating: Technology to protect, prevent corrosion of materials

Thermal spray aluminium coating - Arc Spray method

Thermal spray aluminium coating, Electric arc thermal spraying is popularly used because of its high efficiency and cost and time savings. During the coating process, an arc is formed by the contact of two opposite metal wires (usually with the same composition), resulting in melting at the tip of the wire material. The air atomizes the spray material and accelerates to the surface, the spray speed is adjusted by adjusting the wire feed.

The arc spray process provides high strength and bonding. The low surface temperature and high coverage rate make this method quite suitable for large areas of coating material. Thermal arc coating is used to prevent wear, corrosion, wear and tear, and repair defective components during use.

Thermal spray aluminium coating, Thermal coating with high velocity fuel (HVOF)

This method, fully known as High velocity oxygen fuel (HVOF), is a Thermal spray aluminium coating process that is applied to material surfaces that need a thick, high adhesion coating. Because this method works with the mechanism of pushing the powder of the material in a semi-molten form at supersonic speed to the surface of the part to be coated. The fuel used is hydrogen or kerosene which will be ignited in the combustion chamber, the combustion gas is accelerated in the injection chamber through the nozzle. The goal is to create a large acceleration that accelerates the particles in the mixture. The result is a thin, uniformly distributed, highly durable coating that adheres well to the surface of the part.

Thermal spray aluminium coating, Plasma spray method

The coating material of the plasma thermal spray coating method is in powder form. The coating process consists of spraying a molten or semi-molten coating onto the surface of the material to be coated. Plasma spray coatings can range from a few micrometers to several millimeters thick. This method uses higher temperatures and lower velocities than the HVOF method, so it can be used to cover a wide variety of surfaces, including porcelain.

Thermal spray aluminium coating is a technology to protect and restore the surface of buildings that is always appreciated and widely applied. Depending on the needs and purposes of use, you choose different coating methods.