Creation of heterogeneous materials on the basis of $\mathrm{B}_4\mathrm{C}$ and $\mathrm{Ni}$ powders by the method of cold gas-dynamic spraying with a subsequent layer-by-layer laser action

A method is proposed for creating principally new functionally graded heterogeneous materials on the basis of $\mathrm{B}_4\mathrm{C}$ ceramic powders with different mass fractions in the initial mixture and plastic metallic additive of $\mathrm{Ni}$ by a combined method of cold gas-dynamic spraying with a subsequent layer-by-layer laser action. Mechanical properties of the resultant tracks are examined. It is shown that the track microhardness increases with increasing $\mathrm{B}_4\mathrm{C}$ concentration in the initial 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 $\mathrm{B}_4\mathrm{C}$ 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.