Suchergebnisse

An object of investigation is pointed - the metal articles being in water and exposed to pulse laser treating. The purpose of research was the investigation of the processes occurring near the metal target treated by pulse laser radiation with flux density ∼106 W/cm–2. The results of the experimental investigation of the pulse laser treating of a led target being in water are described. The process of steam and gas plume generation on the surface of the irradiated metal was investigated experimentally. The features of steam and gas plume form and dimensions evolution on different stages of the process (even after completion of laser treating of the material) were investigated. It is shown that when using GOR-100M operating in free oscillating regime (pulse duration 1.2 ms, laser radiation flux density ∼106 W/cm–2), the form of a crater developed on the irradiated target surface being in water essentially differs from the topography of the crater developed on the analogical target surrounded by air at normal pressure (105 Pa). It is pointed in the conclusions that the substantial difference of the forms of crater surfaces developed as a result of processing of the identical targets being in water or air by laser pulses with the identical parameters , determines by principally different character of plasma and steam and gas mixture flow in the mentioned cases.

The results of the structural studies and hardness measurements of the samples obtained by high pressure torsion processing of melt-spun ribbons of Al95.8Mn3.8Fe0.4 alloy are presented in the paper. It has been established that straining of the ribbons results in refinement of microstructure and in the increase of microstrain which leads to increase in microhardness by 2.2 times.

The results of the structural studies and hardness measurements of bi-and three-layer samples obtained by high pressure torsion of melt-spun ribbons of Al-based alloys with amorphous and crystalline structures have been presented. It has been established that straining of amorphous ribbons results in formation of nanocomposite structure while that refinement of crystalline structure and increase of microstrains takes place in crystalline ribbon. It has been found that the hardness of the consolidated samples increases with the increase of the deformation level up to 4,7 GPa.