Renishaw InfiniAM Spectral, User Manual

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Description
7 .1 .1 MeltVIEW
Renishaw has developed a module which monitors the optical emissions from the AM process across
a wide spectral range.
The MeltVIEW module is an in-line opto-mechanical system which integrates seamlessly into
Renishaw AM systems. The device is passive and does not interfere with the laser beam line nor
interrupt or corrupt the signals to/from the motion control system. The co-axial optical configuration
gives a view of the bed which is determined by the laser scanning system ensuring the melt-pool
remains in focus of the sensors throughout the build.
Optical coatings within the system have been tailored to enable the light emitted from plasma and the
melt-pool to propagate to the sensors whilst rejecting the blinding back-reflected laser light. Emissions
from both plasma and the melt-pool are in the near-infrared spectrum.
High optical magnification in a compact form factor ensures the field-of-view of the system is
sufficiently small. A magnified image of the melt-pool is projected onto the sensors and fills the active
region – the surrounding regions have negligible contribution to the signal.
7 .1 .2 LaserVIEW
The laser monitoring module measures the output of the laser in a Renishaw AM system. At the core
of the system is a photodiode which delivers high-speed performance at the laser wavelength. An
infrared sensitive photodiode located behind the first turning mirror in the Renishaw optical module is
used to capture leakage laser light. In doing so, a measurement is made without disrupting the laser
beam characteristics.
The system captures the energy contained in every laser pulse during a build, and short-term
deviations or long-term drift in laser output can be easily identified on a layer-by-layer basis.