Destruction and thermal dissociation of transition metal carbides induced by laser radiation beam

Sintered zirconium-, niobium- and tantalum monocarbides have been irradiated by laser radiation pulses with a duration of 10-3 sec. Different breakdown types have been revealed with the structure unaffected. Those include a plane surface fracture and a hemispherical volume breakdown. The niobium carbide laser beam melting has been proved by studying plates with the accumulated ejection products. A fusion effect along with the brittle fracture is observed for TaC tantalum carbide where a solidified melt layer is metallographically studied in different sections. The layer is of a beam-oriented structure accounted for by an effect of obtaining oriented structures in case of irradiation which has been revealed in a number of materials and is essential for providing layers with anisotropic properties. An X-ray structure analysis of sintered zirconium, niobium and tantalum carbides has shown a minor effect of a lattice period variation. For tantalum carbide the effect has been maximum. Structural changes in a thin surface layer and ejection products have also been studied. Carbon burning-out in open air has been revealed which results in the formation of carbides of the structure with an altered period, carbides with a lower carbon content, basic metals and layers of carbide melts with an oriented structure