| abstract |
1. Sintered material based on transition metal diborides, containing,! a) as the main phase, 90-99 wt.% of a fine-grained transition metal diboride or a mixed crystal of a transition metal diboride from at least two transition metal diborides, or mixtures of such mixed diboride crystals, or mixtures of such mixed diboride crystals with one or more transition diborides metals, with transition metals selected from IV-VI subgroups of the Periodic system,! b) as the second phase, 1-5 wt.% boron carbide and / or silicon carbide in the form of particles and,! c) if necessary, as a third phase, up to 5 wt.% of a discontinuous, oxygen-containing grain boundary phase. ! 2. Material according to claim 1, wherein the main phase a) has an average grain size of less than 20 µm, preferably less than 10 µm. ! 3. Material according to claim 1 and / or 2, wherein the boron carbide and / or silicon carbide of the second phase b) has an average particle size of less than 20 μm, preferably less than 5 μm. ! 4. Material according to claim 1 or 2, wherein the proportion of the second phase b) is 1-4% by weight. ! 5. Material according to claim 1 or 2, wherein the content of the third phase c) is up to 2.5% by weight. ! 6. Material according to claim 1 or 2, wherein the transition metals of the IV-VI subgroups are selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W.! 7. Material according to claim 1 or 2, where the main phase a) means fine-grained TiB2 and / or ZrB2, and / or a mixed crystal (Ti, W) B2 and / or (Zr, W) B2 and / or ( Ti, Zr) B2, preferably a mixed crystal (Ti, W) B2 and / or (Zr, W) B2, more preferably a mixed crystal (Ti, W) B2 or a mixed crystal (Zr, W) B2. ! 8. Material according to claim 1 or 2, wherein the proportion of WB2 in the main phase a) is 7% by weight. ! 9. Powdery sintered mixture for obtaining a sintered material based on diborides of transition metals, containing! 10, |