The technique of measuring the velocity of melt removal in gas-laser cutting technology using multi-channel pyrometer

Multichannel pyrometer was used to measure fluctuations of temperature on the front of action of laser radiation on steel in technology of laser cutting with an assisted gas. Time-resolved measurements were made of local temperature in the five areas with spot size of about 100 mkm each, spaced approximately 0.6 mm apart in the upper part of the front cut. The technique of measuring the velocity of melt removal using the cross-correlation of data of multichannel pyrometer is described. It is shown that the reject filtering allows emphasizing the speed of so-called “fast” and “slow” waves, as the interface velocity. in which they take into account the generation of surface waves in thin film blowing a jet of gas. Obtained experimental data of the velocity of the melt and film thickness are consistent with the results of the model, Chen (1999), which takes into account the gas- jet generation of surface waves on the film.