The steel structure is cleaned and prepared by grit blasting, achieving the necessarry surface roughness of the substrate desired by the procedure.
The desired layer thickness of the choosen metal alloy is built up on the prepared surface. The alloy is choosen for the type of application.
The metallised surface is coated with a high-performance paint system for further protection. This step is optional but usually recommended.
Removing all the oxidized and contaminated layers of the metal
The first step in our process is the removal of all contaminated layers of the steel object. Contamination can be remains of grease, oil or oxidized layers of metal, in other words, rust.
We achieve this by the application of grit blasting. During the process a stream of abrasive material is propelled forcibly against the metal surface. This operation leaves a completely contamination-free surface behind and on the other hand prepares the metal for the next step by increasing the surface roughness to achieve optimal bonding characterestics.
Zink (Zn), Aluminium (Al) and their alloys (Zn/Al 85/15 %) or so called Pseudo-alloys are utilized to form an anti-corrosive coat on the base metal surface. This way we prevent further corrosion by permanently blocking the way of various corrosive agents to the base metal.
We carry out the metal coating with a Flame Spray ( operated with the help of gases ) or with an Arc Spray ( electric arc operated) equipment depending on the nature of application. Both tools are designed to melt and deliver the choosen metal alloys to the target surface.
The metals are "atomised" on 3-6000 Celsius then blasted with the help of high pressure air at the previously cleaned and prepared steel surface. The surface cools down in a very short time and can be handled with bare hands. The extremely high bonding strength(8-31 MPa), anti-corrosive metal coating is formed without a heat shock, often an issue with conventional galvanization techniques.
The typical layer thickness of 100-300 micron of the metal coat grants 20-40 years of anti-corrosive lifespan for the treated steel surfaces even in the harshest corrosive environments.
Typically with the industrial paint system from Tikkurila
The anti-corrosive coating formed by metallisation has a microporous surface. We use an epoxy based filler to prime the surface and fill up the pores. The resulting metal/paint composite layer has extremely good anti-corrosive characteristics.
For the second, final layer we mostly use UV resistant, PU, polyurethane coatings in any desired RAL color. The role of the final layer is to maximise the anti-corrosive lifespan and aesthetic experience.
There is no need for additional layers as opposed to other conventional anti-corrosive technologies.
Could the Thermal Spray Technology be the appropriate choice for my specific anti-corrosive needs and requirements?
Depending on the choice of metals and alloys used, the metallisation process(Thermal Metal Spray) can be successfully applied in any anti-corrosive effort. The respective technological processes are controlled by the following standards: EN ISO 14713: Galvanization; EN ISO 2063: Thermal spraying; EN ISO 8503: Preparation of steel substrates.
Is there a size limit?
As opposed to other, conventional galvanization technologies, when using the Thermal Metal Spray process, you don't have to worry about the size and dimensions of the target object. We can treat any steel object regardless of its weight or geometry given that the necessary conditions are avaliable for the proper application of the technological process. It is important to note that the metallisation process cannot treat the inside surfaces of steel tubings: it is encouraged to always weld them closed.
Which one is better? Metallisation or conventional hot-dip galvanization?
Both of them can be valid choiches. The most appropriate technology should be applied to the given situation or task. We can help you find out which tasks and requirements are suited the best by the Thermal Metal Spray process. A basic principle can be followed: if the given corrosive environment is aggressive chemical, offshore or chloric, ammonic, acidic, submerged or high temperature then only the Thermal Spray Metallisation process can provide appropriate level of anti-corrosive protection.
In which cases should one use Thermal Spray Metallisation instead of conventional hot-dip galvanization?
In the case the target object cannot be fit into the galvanizing bath or if the target object cannot withstand the high, 450 Celsius temperature of the galvanizing bath. The Thermal Spray Metallisation does not inflict heat shock in the target object, there is no chance of deformation. If you require both metallisation and paint coating, our process can be more efficient and economical as both technological steps are carried out in the same place. In the case only partial surfaces have to be treated. When the traditional, galvanized layer cannot withstand the corrosive demands of the given environment. Certain cast irons or specific steel alloys cannot be galvanized in that case metallisation is the right choice too. The metallised surface can withstand temperatures up to 5-700 Celsius. We also think that the metallised surface yields high aesthetic quality. Galvanization is better than rust but metallisation is nicer than a galvanized surface.
What is the maximum achievable layer thickness?
There is no maximum thickness. We work following the specific needs of the client. Typically applied layers: min 100 μm metal coat, 20-50 μm primer, 50-70 μm final coat. The metallised layer can reach 4-800 μm significantly increasing the anti-corrosive life-span.
Previously galvanized steel structure has been modified, welded, cut. Do I have to start all over or it is possible to metallise the previously galvanized elements?
It is possible to treat previously galvanized elements. The respective standards define metallisation as the go-to, appropriate technology for repairing previously galvanized structures. Faulty products that are mended or manipulated after galvanization don't have to be thrown away, we can repair the damaged parts. We can treat partial surfaces.