Mechanical properties of cubic BC2N, a new superhard phase

New Superhard Ternary Borides in Composite Materials

“…12,12 5,60 0,32915 (Lipp & Schvetz , 1975) Due to the strongly extended lattice during the incorporation of Al and Si into the C-C-C axis, the phases B 12 C 2 A1, B 48 C 2 Al 3 and B 12 C 2 Si have a microhardness (HV1 = 25 -30.5 GPa) even lower that that of pure boron carbide (Table 2). A novel superhard phase c-BC 2 N was synthesized using the laser-heated diamond anvil cell with a hardness Hv=76 GPa [Solozhenko, 2001] (Tabl.2). The hardness (50-77GPa) of the new ternary borides is much higher than that of "pure" boron carbide sintered by hot pressing (Tabl.2).…”

Ultimate Metastable Solubility of Boron in Diamond: Synthesis of Superhard DiamondlikeBC5

“…Under the 10 and 20-N loads, we have observed the cracks that allowed us to calculate the reliable load-independent value of fracture toughness, K Ic ¼ 9:5ð2:5Þ MPa m 1=2 , by the method described in Ref. [25]. Nanoindentation measurements have also shown the extremely high value of c-BC 5 nanohardness, i.e., 73(7) GPa.…”

“…Nanoindentation measurements have also shown the extremely high value of c-BC 5 nanohardness, i.e., 73(7) GPa. In Table I, we compare c-BC 5 with diamond, cBN, and boron carbide in terms of mechanical properties [25][26][27][28].…”

“…Experiments at HASYLAB-DESY were supported by the GFZ-Potsdam under the MAX80 program. [11,25]. f Ref.…”

Intrinsic hardness of crystalline solids

“…It should be noted that the experimental hardness of β-BC 2 N is not known yet. In [8], the calculated hardness was compared to an experimental value for cBC 2 N of 76 GPa [21]. Using an observed shear modulus of cBC 2 N of 450 GPa, the hardness was estimated to be 54-74 GPa from Fig.…”