Modification of the tool steel surface with B₄C–Al powders under the influence of pulsed laser

The relevance of laser modification of the surface of metal parts is shown; experimental data are presented on the effect of surface treatment of tool steel 3Kh2V8F with a pulsed ytterbium fiber laser with the addition of a paste of B₄C and B₄C–Al powders. It is shown that a functional layer 30–40 μm thick with microhardness of 1200–1400 HV and a surface roughness of the second class was obtained when processing the surface of the steel sample, on which a layer of paste 1–2 mm thick from F220 (B₄C) powder was previously applied using glue, for 15 min with a laser at optimal operating mode settings. With a similar treatment, but with the addition of PA-4 (Al) powder to the powder F220 (B₄C) in a ratio of 7:3, a functional layer 40–60 μm thick with a microhardness of 1100–1300 HV and a surface roughness of the seventh class was obtained. In the diffraction patterns of the modified surfaces of the samples, a more preferable Fe₂B phase was detected; the FeB phase, which leads to a sharp embrittlement of the functional layer, was not identified.