Laser Cladding
Pore-free and crack-free layers with a long lifetime, high surface quality and exceptional durability.
To the examples
Pore-free and crack-free layers with a long lifetime, high surface quality and exceptional durability.
To the examplesLaser cladding is a process that utilizes either wire or powder coating material, heated by laser beams, to create a molten pool on the surface of the workpiece. The material quickly cools down, creating layers that are metallurgically connected and more resilient coatings created by thermal spraying, while being harmless to health such as hard chromium plating.
Laser cladding with powder
The top-hat beam profile of a diode laser, part of the laser cladding equipment, creates a particularly even molten pool, which provides fine-grained, pore-free and crack-free coatings of the workpieces. Post-processing is thus reduced to a minimum. Integrated into systems for extreme high-speed laser cladding (EHLA) developed by the Fraunhofer ILT, our diode lasers are also suitable for producing very thin coatings that could previously only be achieved by hard chrome plating.
Diode lasers for cladding are used for corrosion and wear protection in a wide variety of areas: in agriculture and forestry, in mines, offshore, in power plants and wherever coatings corrode quickly in the local atmosphere or are subject to increased wear. Laser-coated brake discs, for example, lead to a significant reduction in fine dust emissions and provide better protection against corrosion.
The friction between the brake disc and brake pad generates fine dust, which makes up a relevant proportion of the total fine dust pollution. New coating technologies enable the production of low-wear brake discs with significantly reduced particulate emissions. An additional layer on the base material - made of tungsten carbide, for example - achieves high abrasion resistance and enables the particularly economical production of a new generation of brake discs.
The development of oil and gas fields requires high-performing drilling tools. These are subjected to huge stress and would not reach long lifetimes without wear protection. That is why special coatings, that are more and more frequently realized with the laser coating technology, have become the standard for some time now. Here, Laserline’s LDM and LDF diode lasers have achieved outstanding results: excellent adhesion, high precision, almost no porosity, limited crack formation, a high degree of hardness, and low deformation. In most cases, the created surface does not require any further mechanical processing. In comparison, conventional hard plating methods such as plasma powder cladding do not attain sufficiently long lifetimes.
For customers engaged in oil extraction, mining, metal and paper industries, Technolgenia coats with the help of Laserline's diode laser components with a special tungsten carbide powder.
The typical carbide layers that protect saw-blades, disc harrows or counter blades from wear and corrosion can be optimally realized with the help of diode lasers. Distortion and mixing are kept particularly low by a quiet molten pool and minimal heat input. Coating thicknesses as well as track widths can be variably and specifically built up. Oversizes during coating are kept to a minimum, so that the economic efficiency combined with the technical advantages make a strong team for agricultural components.
A growing market is laser coating of hydraulic cylinders in technical mining facilities for example coal extraction. The coating of the cylinder corrodes very quickly under the local atmosphere which leads to leaking hence a replacement or new coating will be necessary. Until now chrome plating was the primary method which will be replaced more and more by laser coatings due to their superior durability. The specific increase of durability can’t be quantified yet however current results show an increase in the lifetime of more than 100%.
The main motivation is the protection against highly corrosive gases or liquids which come into contact with the metal heat exchanger affect negatively its life cycle. Therefore nickel alloys with low hardness properties are mostly used which avoids cracking and can be applied up to 1 mm thickness. Even at high temperatures they lead to a better wear protection against corrosive media. Deposition rates of 8 kg/h are possible.
Chlorine attacks metal, a fact that is known all too well by operators of biomass facilities and incineration plants. But why? The boiler walls of such plants consist of water-bearing steel pipe systems that absorb the thermal energy of the firing and then transfer it to the water-steam circuits. But the chlorine in the flue gas of the firing breaks down the pipes. Untreated, they are often no longer usable after one year. It seems reasonable then to assume that this cannot be economical.
Meanwhile, many plant operators therefore count on anti-corrosion coatings. This is already worth the effort as soon as the duration of the operation is doubled — and even more can be achieved: compared to uncoated pipes, and depending on the applied material and physico-chemical load, a tripling or quadrupling of the lifespan is possible.
Which laser systems are particularly suitable for laser cladding? Here you will find a selection.
