CREATION OF HETEROGENEOUS MATERIALS ON THE BASIS OF B_4C AND Ni POWDERS BY THE METHOD OF COLD SPRAYING WITH SUBSEQUENT LAYER-BY-LAYER LASER TREATMENT

摘要

A method is proposed for creating principally new functionally graded heterogeneous materials on the basis of B4C ceramic powders with different mass fractions in the original mixture and plastic metallic additive of Ni by a combined method of cold spraying with subsequent layer-by-layer laser treatment. Mechanical properties of the resultant tracks are examined. It is shown that the track microhardness increases with increasing B4C concentration in the original mixture. The track structure is found to depend on the size of ceramic particles in the interval from 3 to 75 mu m. Reduction of the B4C particle size (approximately by a factor of 2-3) inside the track owing to fragmentation under the action of the laser beam is observed for the first time.