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In laser materials processing, the CSIR
National Laser Centre has developed a comprehensive technology
base consisting of state-of-the-art equipment, complemented
by a team of metallurgical engineers and physicists. Activities
include research and development projects focusing on the
processing of various materials. Current research focus
is on the processing (welding, laser assisted metals deposition
or cladding, and surface treatment) of nickel based alloys,
as well as light metals such as aluminium alloys and titanium.
The laser materials processing group regularly conduct feasibility
studies for industrial clients aimed at finding laser-based
solutions to manufacturing problems. The portfolio of laser
machining processes researched, developed and offered by
the CSIR includes laser cutting, 3D cutting of sheet metal
pressings, laser deep penetration welding, laser cladding/surfacing,
laser hardening and laser assisted ablation / engraving
/ milling.
Facilities:
The main facility of the laser materials processing group
is based on two high-power laser systems.
1. Trumpf Lasercell TLC1005
The first laser system installed at the High Power Laser
Facility was a Trumpf TLC1005 Lasercell fitted with a 5000HQ
CO2 laser resonator. This 5 kW laser system is configured
as a five axis gantry based system, with a sixth rotational
axis for cylindrical components. This system is suitable
for the processing of ferrous metals, and is used in all
the CSIR National Laser Centre research and development
activities in thick section cutting, deep penetration welding,
and 3D processing of sheet metal. The CO2 laser provides
laser radiation at 10,6 µm, which is in the infrared
spectrum. |
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| Trumpf Lasercell TLC1005 |
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2. The Rofin DY044 Nd:YAG laser and KUKA robot
The CO2 laser system is complemented by a Rofin DY044 Nd:YAG
laser, which is integrated with a KUKA KR 60 L30 HA robot.
This 4 kW diode pumped laser is coupled into two 400 micron
core fibre optic cables to allow the robotic delivery of
the laser beam to the work piece. This laser produces laser
radiation at 1,06 µm, which has a better coupling
efficiency into metals compared to the longer wavelengths
produced by the CO2 lasers. This laser system is used for
processing of light metals, as well as laser cladding and
laser hardening research and development tasks. |
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| The Rofin DY044 Nd:Yag laser facility, showing the beam
`delivery system integrated with a KUKA robotic arm |
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Ancillary equipment:
Laser welding accessories:
Both systems are comprehensively equipped with a range of
laser welding heads, which include laser/MIG hybrid welding,
variable twin-spot laser welding heads and scanner based
beam delivery systems for laser hardening and surface modification
tasks.
Laser cladding:
The CSIR National Laser Centre has access to a range of
metal powder delivery nozzles that is used for laser cladding
or metals deposition. In this process, metal powder is injected
into a melt pool created on a workpiece that allow the formation
of new metal layers, or new alloys. Co-axial nozzles as
well as various off-axis nozzles allow researchers to optimise
process parameters. A GTV powder feeder supports this competency.
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| Deckel Maho Gildemeister Lasertec DML40s laser ablation system |
3. Laser ablation facility
The CSIR National Laser Centre also has a laser ablation
system that is used for deep engraving or laser milling
tasks. Laser ablation is a process where very thin layers
of material are removed from a surface in a controlled way
by laser pulses emitted by laser source. This 40 micron
diameter focused laser spot is guided over a surface at
a fast rate, employing a series of guiding mirrors.
The process is controlled by computer assisted machining
software. This enables the creation of very fine profiles
and structures in most metals as well as ceramics by evaporating
the unwanted material.
The result is then a small tool or prototype that is within
specification. This process relates mostly to tooling in
the coining, plastic injection moulding and printing industries.
Miniature prototypes and aerospace components are developed
with this advanced technology. |
4. Metallurgical laboratory
The metallographic laboratory contains sample preparation
equipment such as automatic polishing machines and etching
equipment. The laboratory also houses analytical equipment
such as optical microscopes and a micro-hardness tester.
The metallurgical microscope and hardness tester are coupled
with an analysis computer program, which aids in capturing
and analyses of micrographs. |
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Sample preparation and
microscopic equipment in the metallurgy laboratory |
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