Welding Turbine Components
Turbine engines require high quality joining methods to withstand their high operational temperatures. Common methods involve vacuum brazing using expensive braze alloys, many hours of manual deposition of the braze paste and long cycles at high temperature in a braze furnace. Compared to these techniques, Laser welding offers many benefits:
- Parts do not need to be designed with a gap for braze alloy to flow
- No fixtures are required to hold the parts in position, waiting for the end of the braze cycle to fix them in place
- Laser welding is faster with no braze furnace cycle
- The process requires minimal tooling
- Lower rework costs
- The temperature cycle of the whole parts is less
- Final components do not have any low melting point alloys to soften during operation.
Laser welding of all different joint designs are possible such as butt, lap, and fillet joints to suit the application, access and mechanical requirements. Lasers with incorporated time-share units to send the output from one Laser to multiple workstations are often used to maximise capability and to handle the longer assembly time of components. In all cases, the use of fiber optic beam delivery is best because of its constant focus spot size, working distance and ease of integration into Cartesian and robotic motion systems.
redENERGY Pulsed Fiber Lasers offer excellent control and low heat input characteristics. The ability to shape the Laser pulses and produce a wide, shallow weld make them good candidates for some of the smaller components.
For deeper penetration and higher speed welding of larger parts such as combustor cans and liners redPOWER CW Lasers are the best choice. They eliminate cracking when welding some superalloys.
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