Surface treatments of materials using high power
CO2 lasers typically involve moving a substrate
under the laser beam and generating a melt zone;
concurrently, metal or ceramic or a combination of
metal + ceramic in the form of powder is introduced
into the melted zone by a feeding device, or by
preplacing the powder on the substrate surface
before laser melting. The melted zone is cooled
rapidly by heat conduction through the substrate.
The method can be used to enhance wear, corrosion,
and erosion resistance. For example, laser melting a
CP Ti substrate with continuous feeding of aluminium
has been used to generate surface layers of
titanium aluminide which are potentially useful for
improving the oxidation resistance [1, 2]. The layer
dimensions and compositions can be controlled by
appropriate selection of laser processing parameters
(such as laser power, powder feed rate, traverse
speed