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Laser surface and interface engineering: thick coatings and applications

The surface condition of a component is usually the most important engineering factor. Almost inevitably the outer surface of a work-piece is subjected to wear and corrosion while it is in use. To an increasing degree, therefore, the search is for surface modification techniques, which can increase the wear resistance of materials. In our work two high-power laser techniques are used for the surface engineering of metallic alloys: Laser cladding, which allows the deposition of thick resistant metallic by a melting process fusing a special alloy onto a weaker substrate and Laser hardening, which produces wear resistant tracks by microstructural transformations, i.e. a laser beam scans across a component without melting.

lasers_1New trends in laser surface treatment techniques in our research program lie in developments of novel micro, nano and amorphous structures at the surfaces as well as in microcladding processes and metal foaming. To fulfill these requirements a new 3 kW IPG Fiber laser was installed in December 2008 and January 2009 in the group and supported by FOM/M2i. It represent the very first Fiber laser of this type in the Netherlands. The fiber laser, a special type of the solid-state laser, represents a new generation of high-power lasers for materials processing.

INTERNATIONAL JOURNAL OF MATERIALS RESEARCH Volume: 100 Issue: 10 Pages: 1343-1360 Published: OCT 2009

SURFACE & COATINGS TECHNOLOGY Volume: 203 Issue: 20-21 Pages: 3189-3196 Published: JUL 15 2009

laser optics and cnc tableThe modern experimental technique – so called Digital Image Correlation – is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and tested to measure in-situ the strain during treatment with a high power 2 kW CW Nd:YAG laser, i.e. laser hardening, surface remelting, and laser cladding with Nanosteel, Eutroloy 16012 and MicroMelt 23 powders, on C45 steel and 301 stainless steel plates using the commercial 3D digital image correlation system. The in-situ strain was measured at the bottom surface of the 5 mm thick plate using a mirror located under the plate. Experimental measurements allow discrimination between thermal and residual strains. The strain build-up in the direction parallel and perpendicular to the laser cladding direction were measured for different laser surface treatment setups and for laser cladding of all three powders. The observation provides very useful information concerning laser surface treatment (surface hardening and surface remelting) and laser cladding. Analysis of these measurements could help to optimize the laser cladding parameters with an aim to suppress the formation of high level internal strains.







movie1 (Coaxial Laser Cladding - Adobe Flash movie)

movie1 (Laser Hardening - Adobe Flash movie)

movie1 (Laser Melt Injection - Adobe Flash movie)

SURFACE & COATINGS TECHNOLOGY Volume: 203 Issue: 20-21 Pages: 3189-3196 Published: JUL 15 2009
SURFACE & COATINGS TECHNOLOGY Volume: 201 Issue: 12 Pages: 5875-5883 Published: MAR 5 2007
SURFACE & COATINGS TECHNOLOGY Volume: 197 Issue: 2-3 Pages: 127-136 Published: JUL 22 2005