Optical monitoring of temperature evolution and temperature distribution in laser machining provides important
information to optimise and to control technological process under study.
The multi-wavelength pyrometer is used to measure brightness temperature under the pulsed action of Nd:YAG laser on
stainless steel substrates. Specially developed "notch" filters (10-6 transparency at 1.06 μm wavelength) are applied to
avoid the influence of laser radiation on temperature measurements. The true temperature is restored based on the
method of multi-colour pyrometry.
Temperature monitoring of the thin-walled gilded kovar boxes is applied to detect deviation of the welding seam from its
The pyrometers are used to control CO2-laser welding of steel and Ti plates: misalignment of the welded plates, variation
of the welding geometry, internal defects, deviation of the laser beam trajectory from the junction, etc. The temperature
profiles along and across the welding axis are measured by the 2D pyrometer.
When using multi-component powder blends in laser cladding, for example metal matrix composite with ceramic
reinforcement, one needs to control temperature of the melt to avoid thermal decomposition of certain compounds (as
WC) and to assure melting of the base metal (as Co).
Infra-red camera FLIR Phoenix RDAS provides detailed information on distribution of brightness temperature in laser
cladding zone. CCD-camera based diagnostic system is used to measure particles-in-flight velocity and size distribution.