Bushma O. Modelling of the processes of laser radiation interaction with dispersed materials in laser and hybrid laser-plasma deposition of coatings

The thesis is devoted to investigation of laser and hybrid laser-plasma processes of coating deposition, to development of physical-mathematical models of laser and combined heating of fine-dispersed materials and to definition of new methods for thermal characteristics control of particles being sprayed on this basis. The theory of laser radiation interaction with particles of fine-dispersed materials was developed. The formulae to calculate the characteristics of absorption and scattering of laser radiation by particles being sprayed were obtained. The mathematical model of laser and laser-plasma heating of fine-dispersed materials was proposed. The possibility of control of temperature fields inside particles being sprayed by an appropriate combination of laser and plasma heating method was proved. The mathematical models of motion and heating of individual particles were developed as applied to laser, plasma and hybrid spraying of ceramic coatings without and with taking into account the laser beamscattering and absorption by all the totality of particles at laser spraying. The design of integrated laser + non-transferred arc plasma torch was proposed, and its prototype was manufactured. The wide prospects for its using in spraying different ceramic and metallic materials, as well as in synthesis of diamond and diamond-like coatings, were proved.