LASER & PTA CLADDING/HARDFACING
1. Laser Cladding
The laser cladding process is essentially a welding process utilizing an infinitely controllable laser beam as its heat source. This technology allows for complete metallurgical bonding with minimal HAZ (heat affected zone) and dilution, along with a reduction in other undesirable side effects such as oxidation and decarburization. Unlike thermal spray processes, laser cladding can be used to recover, or even enhance, the mechanical properties of a component or substrate. The ability to clad/weld very thin sections, edges, and complex geometries with an overlay that is metallurgically superior to the substrate makes the previously impossible, possible.
Benefits of Laser Cladding
- Minimized HAZ
- Metallurgical bond
- Surface modification (heat treating)
- Broad range of materials/overlays
- Very low heat input
- Greatly reduced decarburization
- Guide vanes
- Wear rings
- Pilot nozzles
- Transition pieces
- Seal faces
- Oil tools
Laser Cladding Materials
- Stainless steel alloys – 304, 316L, 410, 420
- Corrosion resistant alloys – Hast-X®, 625, 718
- Hardfacing alloys – Stellite® 1, 6, 12, 20, 21 Colomonoy® 69, 88, Durum® 059, Triballoy®T-800
- Tungsten carbide composites – 50%, 60%, 70% WC
- Aluminum bronze
- 4kW disc laser, coaxial nozzle, six axis robot with two axis positioner, 680 kg (1500 lb) max capacity.
- 4kW disc laser, coaxial nozzle, six axis robot with two axis positioner, 2040kg (4500 lb) max capacity.
2. PTA Cladding/Hardfacing
Plasma transferred arc (PTA) Cladding/hardfacing is a versatile method of depositing high-quality metallurgically fused deposits on relatively low-cost surfaces. Soft alloys, medium and high hardness materials, and carbide composites can be deposited on a variety of substrates to achieve diverse properties including wear and corrosion resistance at ambient or elevated temperatures. PTA hardfacing has several significant advantages over traditional welding processes such as oxyfuel (OFW) and gas tungsten arc (GTAW) welding.
- PTA is easily automated, providing a high degree of reproducibility.
- It allows precise metering of metallic powder material, making it highly efficient and cost effective when compared to traditional welding processes.
- It permits precise control of important weld parameters i.e. powder feed rates, gas flow rates, amperage, voltage, and heat input, ensuring a high degree of consistency from lot to lot and component to component.
- It produces deposits of a given alloy that are tougher and more corrosion resistant then counterparts laid down by GTAW or OFW processes. Weld deposits are characterized by very low levels of inclusions, oxides, and discontinuities.
- It produces relatively smooth deposits that significantly reduce the amount of post weld machining required.
- It parameters can be adjusted to provide a variety of deposits in thicknesses from 1.2 to 2.5 mm (0.050 to 0.100 in.) or higher. These can be deposited by a single pass at a rate of 2lb/hr up to 10lb/hr depending upon the torch, powder and application.