Spectroscopic characterization of plasma plume induced in TiC formation by pulsed Nd:YAG laser

Spectroscopic study of the plasma plume induced in TiC formation through the laser irradiation of pasted graphite layer on titanium substrate was performed. The experiments were carried out using a long pulsed Nd:YAG laser by variation of pulse duration and process speed. The alloyed layer properties were considered through plasma plume characterization. The plasma temperature and temperature standard deviation for various pulse durations and process speeds were obtained. Moreover, the recorded spectra of the plasma plume respected to the treated samples were investigated by applying the new method known as covariance mapping technique (CMT) and the results were compared with the experimental alloyed layer properties.A significant relation can be found between the micro-hardness values of the alloyed layers and the correlation or anti-correlation behavior of the plasma plume species.

► Online characterization of plasma plume is used to evaluate the TiC created layer.
► New technique of covariance mapping analysis is introduced in laser surface alloying.
► Larger positive covariance maps occur in the formation of more TiC contained layers.
► Negative covariance maps imply minor role of the Ti lines in the plasma plume.