Structure and properties of superhard materials based on aluminum dodecaboride α-AlB12

• Published in: Journal of superhard materials 2017-09, Vol.39 (5), p.299-307
• Main Authors: Prikhna, T. A., Barvitskyi, P. P., Karpets, M. B., Muratov, V. B., Sverdun, V. B., Khaber, P., Kartuzov, V. V., Moshchil’, V. E., Dub, S. N., Loshak, M. G., Aleksandrova, L. I., Kovylyaev, V. V., Garbuz, V. V., Marchenko, A. A.
• Format: Article
• Language: English
• Subjects: Additives; Aluminum; Chemistry; Chemistry and Materials Science; Contact pressure; Fracture toughness; Hardness; Hot pressing; Mechanical properties; Physical Chemistry; Production; Properties; Sintering; Structure; Titanium carbide
• ISSN: 1063-4576; 1934-9408
• DOI: 10.3103/S106345761705001X

The structures and mechanical properties of materials based on α-AlB12 without additives and with additions of carbon and titanium carbide sintered under high (2 GPa) pressure and by hot pressing (30 MPa) in the contact with hexagonal BN. The light materials were obtained having high hardness, fracture toughness, ultimate strengths at bending, R bm , and compression. The addition of 17 wt % C to α-AlB 12 and sintering at 30 MPa makes possible to achieve fracture toughness K I c (49 N) = 5.9 ± 1.4 MPa·m 0.5 , hardness H V (49 N) = 23.6 ± 2.8 GPa, bending R bm = 310 MPa and compression R cs = 423 MPa strengths and specific weight was γ = 2.7 g/cm 3 . The addition of 20 wt % TiC to α-AlB 12 and sintering at 30 MPa resulted in the formation of AlB1 2 C 2 and TiB 2 , increase of the hardness H V (49 N) = 28.9 ± 1.9 GPa, R bm = 633 MPa, R cs = 640 MPa and γ = 3.2 g/cm 3 , the K I c (49 N) = 5.2 ± 1.5 MPa·m 0.5 .