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ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

OPTICAL MEASUREMENTS OF SURFACE TEMPERATURE IN LASER MACHINING

Get access (open in a dialog) DOI: 10.1615/IHTC10.3090
pages 255-260

Abstract

The thermal state of material in the zone of laser action is one of the main integrated parameters to determine the evolution of physicochemical processes and structural phase transformations. The conditions of temperature measurements in laser machining are among the most severe even for noncontact techniques of optical pyrometry. From a general point of view, the absence of on-line control and monitoring is one of the main limitations of laser technology integration into modern industry. Data on surface temperature dynamics obtained by pyrometry could be widely used to: (a) understand and optimize the laser processes (i.e. define of the links between surface temperature history and the properties of treated materials; (b) create process control including feedback from a pyrometer. The main technical parameters of the developed pyrometer are the following: brightness temperature range 1150K (1550K)-3500K (threshold sensitivity vity depends on selected wavelength); error of measurement 1%, response time 190 µs; 200 µm spatial resolution at 350 mm distance of pyrometer from the zone of temperature measurements; variation of wavelength 2 colour chanels from 0.5 to 1.1 µm µm. The opportunities of actual temperature measurements by high speed high spatial resolution pyrometer system in a wide range of laser applications are illustrated by: heat treatment, welding, cladding and alloying.