Figure 5
From: Ultrahard stitching of nanotwinned diamond and cubic boron nitride in C2-BN composite
Mechanical and electrical properties of C2-BN nanocomposite.
(a) Hv of C2-BN as a function of applied load. Left inset: Optical micrograph of an indentation in C2-BN produced by a load of 19.6 N. Right inset images in (a) show profiles across d1 and d2 measured using a 3D microscope. (b) Hv as a function of composition for Cx-BN materials. For comparison, we measured the Vickers hardness of Cx-BN with higher diamond:cBN ratios at only the highest load of 19.6 N. The measured indentation hardness of Cx-BN ranged from 40 GPa to 85 GPa. (c), Thermogravimetric data (in air) for C2-BN (the onset temperature of oxidation Tox is 1183 K) and boron-doped diamond single crystals (Tox~1027 K). (d) A resistance-versus-temperature curve for C2-BN measuring 2 × 2 mm and 1 mm thick. The inset in (d) shows ln (R) as a function of T−1 in the temperature range from 50 to 100 K. The linear fit (solid line) shows that the data are well described by R(T) ∝ exp(Eg/kBT), where Eg is the activation energy and kB is Boltzmann’s constant.
