OPTIMIZATION OF THE REGIMES OF OBTAINING DIAMOND-LIKE CARBON COATINGS WITH HIGH PERFORMANCE CHARACTERISTICS BY THE LASER-PLASMA METHOD

The formation of a diamond-like carbon coating on a substrate as a result of the action of the radiation of an industrial laser (t ~ 20 ns, λ = 1.06 μm) on a target of the highly oriented pyrolytic UPV-1 graphite in a vacuum was investigated. It is shown that by changing the power density of the laser radiation on the surface of such a target, the velocity of scanning of the laser beam over the target surface, the laser pulse repetition frequency, and the temperature of the target, one can control the ratio between the sp² - and sp³ -carbon bonds in the coating applied to a substrate. It was established that a diamond-like carbon coating with a predominant content of the sp³ -bonded carbon is formed at a laser power density q ≥ 5.6∙10⁸ W/cm ² . In this case, it is advisable to select the laser pulse repetition frequency and the velocity of scanning of a laser beam over the surface of a target so that 10 to 14 laser pulses fall successively into one and the same area of the target surface. It is shown that, in the case where a target has a temperature T ≥ 423 K, the content of the sp³ -linked carbon in the coating applied to a substrate decreases sharply, with the result that the properties of the coating deteriorate.
The formation of a diamond-like carbon coating on a substrate as a result of the action of the radiation of an industrial laser (t ~ 20 ns, λ = 1.06 μm) on a target of the highly oriented pyrolytic UPV-1 graphite in a vacuum was investigated. It is shown that by changing the power density of the laser radiation on the surface of such a target, the velocity of scanning of the laser beam over the target surface, the laser pulse repetition frequency, and the temperature of the target, one can control the ratio between the sp² - and sp³ -carbon bonds in the coating applied to a substrate. It was established that a diamond-like carbon coating with a predominant content of the sp³ -bonded carbon is formed at a laser power density q ≥ 5.6∙10⁸ W/cm ² . In this case, it is advisable to select the laser pulse repetition frequency and the velocity of scanning of a laser beam over the surface of a target so that 10 to 14 laser pulses fall successively into one and the same area of the target surface. It is shown that, in the case where a target has a temperature T ≥ 423 K, the content of the sp³ -linked carbon in the coating applied to a substrate decreases sharply, with the result that the properties of the coating deteriorate.
Author:  V. K. Goncharov, G. A. Gusakov, M. V. Puzyrev
Keywords:  erosion laser torch, ion fl ows, diamond-like carbon coatings
Page:  753