The Plasma Transferred Arc (PTA) process recommends itself due to its ease of automation and thus a high degree of reproducibility of the welded overlays. In addition, because of the highly concentrated heat source, this process benefits from high powder utilisation and can achieve a very low level of iron dilution in the overlay. Because the hardfacing materials are in powder form, it is possible to produce overlays from many different materials and combinations of materials with a wide range of hardness and other properties. For this reason Wisdom offers the widest range of hardfacing materials for this process.
Advantages:
- Highly automated
- High powder utilisation
- Low dilution
- Very wide range of hardfacing materials
When overlaying with a laser an optical arrangement is used to focus the laser beam on the work piece and heat it. Simultaneously hardfacing material in the form of owder is introduced into the laser beam and melted. Due to the narrow heat affected zone and the fast cooling rate the heat input is low, thereby producing an almost stress free overlay.
Compared with other welding processes with higher heat inputs, for a given hardfacing alloy the fast cooling rate of the laser process produces an overlay with a significantly higher hardness and finer microstructure.
Advantages:
- Low Heat Input
- Fast Cooling
- Almost Stress Free Overlays
- High Hardness
- Fine Microstructure
