Laser Metal Deposition (LMD) is a process which uses a laser beam to form a melt pool on a metallic substrate, into which powder is fed. The powder melts to form a deposit that is fusion bonded to the substrate. The required geometry is built up layer by layer. Both the laser and nozzle from which the powder is delivered are manipulated using a gantry system or robotic arm.
LMD is used for a wide range of applications, including the generation of 3D free form structures and for cladding and repair applications.
LMD technology aims to address the following industrial needs:
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Reduction of manufacturing waste material
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Reduction of tooling costs
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Repair of parts that are costly to replace or difficult to repair effectively
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Reduction of component lead times
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Customisation of parts on the fly
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Deposition of novel materials
TWI has specific experience of LMD projects across a diverse range of industries including:
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Repair of mould tool surfaces
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Repair of high value parts such as aero engine components and military vehicles
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Tipping of turbine blades with protective coatings
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Surfacing of oil and gas drilling components
TWI has been at the forefront of LMD development for nearly a decade. As part of this development work TWI has gained valuable knowledge and experience of LMD capability in the following areas:
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Component repair, original part build, hybrid manufacture or material surfacing
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Closed loop feedback control for regulating deposit height
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5-axis motion control to facilitate deposition in three dimensions
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Deposition of reactive metals with and without the use of a protective atmosphere
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Depositions of a wide range of materials, including Nickel superalloys, titanium Ti-6Al-V4, hard-facing materials and high strength steels
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Deposition of metallic glasses and amorphous materials
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Powder recycling methods for better process efficiency
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Micro-focus X-ray facility for inspection of porosity and surface roughness
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Bespoke DMD CAM software for complex 3D tool-path generation
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Experience with functionally graded materials
TWI LMD facilities include:
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Trumpf 5-axis gantry CO2 laser deposition system
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7kW IPG Yb-fibre laser
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Kuka robot based high deposition rate cell
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Kawasaki robot based deposition cell
One of the advantages of LMD is the ability to add material to an existing structure for repair applications. An example of this was when Rolls Royce in partnership with TWI and initially the University of Birmingham developed a LMD repair procedure for Single Crystal (SX) turbine seal segments. This procedure was so successful that Rolls Royce arranged the installation of a LMD production facility to repair their Trent 500 segments allowing them to save significant costs over the lifecycle of their Trent turbines.
LMD also allows for near net shape manufacturing which dramatically reduces waste material and tooling costs.
For further information or if you have any questions please do not hesitate to contact us.
