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Principle set-up of deposit welding
with
powder.
A.Gasser, Fraunhofer-Institut
f. Lasertechnik, Aachen |
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Cladding of turbine blades
ALSTOM Power |
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Cladding of shafts
Tampere University of Technology, Tampere |
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Advantages
of laser cladding with powder |
• local heat
input
• low thermal load
• little distortion
• contact-free
• precise layer deposition
• high efficiency of powder use |
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Laser Cladding with Powder
Wear protection and repair layers can be generated by
laser deposition from metallic powder locally and by
minimizing the heat load to the work piece. The powder
is fed into the melting zone on the surface of the work
piece by using a carrier gas. Even with moderate power
densities of only several 103 W/cm2 layers with a thickness
of 0.5 to 1 mm and paths with a width of up to a
few millimeters can be deposited at a speed of several
100 mm/min. Thicker layers and wider paths can be generated
by scanning several layers one upon the other and in
parallel ways.
Applications
- turbine blades
- valves and/or valve seats
- punching tools
- deep drawing tools
- die casting tools
- rapid prototyping
Due to the better absorption of laser radiation on metal
surfaces and in powder particles at shorter wavelengths,
solid-state lasers are usually more efficient and more
cost-effective for powder cladding than CO2 lasers. Especially
high-power diode lasers are ideal for these requirements,
as they are providing an optimal wavelength (800 – 1000 µm)
and a high efficiency but a small size. |
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High-Power
Diode Laser ROFIN DL 031 Q
The 2nd generation of high-power diode lasers provides
high reliability due to sophisticated controlling sensors
and stack management. High efficiency and moderate
operating costs make it the ideal tool for powder laser
deposition, in particular also in the fiber-coupled
version. This applies to deposition geometries in the
millimeter range, for more tiny deposits with geometries
in the sub-mm-range, cw-YAG lasers are more suitable.
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