Laser Cladding: An Innovative Localized Hard-facing Technique
Laser cladding is a cutting-edge welding process that has the capability to modify the surface properties of a substrate with exotic and/or harder materials. In this process, the feedstock in the form of micron-sized alloy powder, is melted by a laser beam to deposit a durable overlay with a thickness of 0.5 to 2 mm.
IBC Coatings Technologies offers laser cladding as a localized treatment for extending the operational service life of components and systems by increasing resistance to wear, corrosion, and erosion in a wide variety of applications and environments.
Why Laser Cladding
Traditional cladding techniques often require excessive heat input, which may result in negative effects on performance of the whole component, such as distortion and reduced mechanical properties. In contrast, the heat input of the laser beam can be accurately adjusted. It has minimal side effects on the mechanical integrity of the component, and can either locally treat the damaged area or improve the surface properties for a specific part in the chain of manufacturing.
The unique advantages of laser cladding over arc-based and thermal spray coating techniques are:
- Highly concentrated heat input with very narrow heat affected zone
- Durable metallurgical bond with minimal dilution
- High deposition rate
- Capability of cladding a wide variety of materials, even those with poor weldability
- Cost-effective due to few required pre/post processing treatments
- Exceptional weld quality in terms of both mechanical and surface properties due to greatly lowered defects such as porosities and cracks
- Precisely controllable
- 4 kW IPG fiber laser
- Headstock/tailstock positioner with capacity of 4000 lbs coupled with maximum diameter of 12 in and maximum length of 11 ft
- Wide selection of cladding materials
- Research and development / feasibility studies
- Equipped with in process quality analysis
Commonly utilized materials
- Stainless steel (3XX, 4XX, 17-4PH)
- High strength steels (M2, H13)
- Rockit ™
Failure Modes that Laser Cladding Can Solve
- General wear
- Abrasive erosion
- Hot gas oxidation
- High temperature corrosion-erosion-wear
Target industries who can benefit
- Oil and gas
- Power generation
- Mining/heavy equipment
- Food processing
- Wear sleeves
- Seal/bearing journals
- Rotor shafts
- Pump shafts
- Compressor wheels
- Gearbox housing
- Propeller shafts
- Exhaust valves
- Crank shafts
- Engine components
Laser Cladding Case Studies
Tines utilized in automated agricultural equipment are exposed to continuous highly abrasive wear and erosion. This exposure can cause segments of the tines to fail, leading to considerable replacement costs. In order to improve the wear resistance of these tine segments, IBC Coatings Technologies applied laser cladding. The cladding material is an iron-based alloy reinforced with carbides. The tines’ performance in service condition showed that the cladding significantly improved wear resistance.
Bottom punch/magnet dies
When magnets are produced for motors, the magnet material is combined in a slurry and set into a die. Then, punches force the slurry into the magnet die and force all the water/contaminants out of the slurry. These punches must have non-magnetic tips, so they don’t interfere with the magnet’s polarity. In addition, the dies are subject to high metal to metal wear.
Traditionally, Stellite 6 was applied to the top surface via GTAW. However, the dilution line between the base material (W2 steel) and the substrate (Stellite 6) was choppy, and the manual process was time consuming (roughly 1 hour per punch).
IBC proposed an automated solution to improve productivity. The solution used a coaxial powder feed laser head, and custom programming was implemented to map the clad/layer paths.
IBC was able to produce a buildup of Stellite 6 that exhibited a very clean dilution line between the parent and clad material, and produced a cladding in 15-20 minutes as opposed to 1 hour. Hence, quality and productivity were improved drastically with this automated solution.
Laser Cladding for Restoration of Damaged Area
Wind Turbine Centrifuge Hubs/Shafts
Wind turbine hubs and shafts are subjected to wear due to load variation resulting from changes in wind speed/intensity. This wear can cause the gearboxes to fail prematurely, leading to high replacement costs.
IBC Coatings Technologies applied laser cladding to worn hubs, journals, and shafts, which were then machined to original design specifications. Base materials included a variety of stainless steels (410 SS, 420 SS, 440 SS). The prime cladding material was 420 stainless steel. Careful control of the preheat and process parameters ensured the clad material was free of defects and had similar/improved properties compared to the base material.
Steel Mill Rods
Steel mill rods are components which are subjected to frequent wear. Usually the wear is minor, but sufficient to make the rod no longer usable. IBC Coatings Technologies applied laser cladding to worn rods. Base material was a high strength steel (4140), and 431SS martensitic stainless steel was picked as the overlay in order to improve the wear resistance of the substrate.
Based on quality analysis after laser cladding, it was revealed that the hardness of the overlay experienced a smooth transition toward the substrate, confirming that laser cladding leads to metallurgical bonding. Additionally, there was no sign of a heat affected zone immediately at the overlay/substrate boundary.