Crystallographic anisotropy of wear on a polycrystalline diamond surface

Abstract

We correlate topography and diffraction measurements to demonstrate that grain orientation profoundly influences polishing rates in polycrystalline diamond synthesized by chemical vapor deposition. Grains oriented with {111} or {100} planes perpendicular to the surface normal polish at significantly lower rates compared with grains of all other orientations when the surface is polished in continuously varying in-plane directions. These observations agree with predictions of the periodic bond chain vector model, developed previously for single crystals, and indicate that the polishing rate depends strongly on the number of periodic bond chain vectors that are within 10° of the exposed surface plane

Nanolayered Diamond Sintered Compact Obtained by Direct Conversion from Highly Oriented Graphite under High Pressure and High Temperature

“…They suggested that the high wear resistance of NPD is attributed to the extremely strong binding nature of the constituent nanocrystals and the presence of a number of grains with {111} planes facing to the surface. Indeed, a careful abrasion test conducted using CVDgrown micropolycrystalline diamond by El-dasher et al, [19] demonstrated super wear resistance of {111} planes. Since our new nanolayered diamond has top surfaces which are terminated exclusively by {111} due to the strong preferred orientation of individual crystals, it is expected to provide significantly higher antiwear performance.…”

Etching mechanism of diamond by Ni nanoparticles for fabrication of nanopores

“…However, analyzing molecules in harsh conditions such as extreme temperatures, voltages or pH conditions could lead to the malfunctioning or in extreme cases to the destruction of the chips with conventional membranes. The problem can be solved by establishing nanopores in diamond since this material possesses exceptional physio-chemical properties such as the highest hardness and Young's modulus (1200 GPa) of all known solids, a very high thermal conductivity (20)(21)(22) W cm −1 K −1 ) and a low thermal expansion coefficient [9], [10], [11], [12]. Furthermore, because of its wide band gap, the electrochemical potential window of diamond is significantly larger and the background current within this regime considerably lower than conventional electrodes made from metals or graphite [13].…”

Anisotropic etching of diamond by molten Ni particles

“…Diamond is the perfect candidate for this task since it has exceptional properties such as the highest hardness and Young's modulus ͑1200 GPa͒ of all known solids, a very high thermal conductivity ͑20-22 W cm −1 K −1 ͒ and a low thermal expansion coefficient. [4][5][6][7] It can be used to attach binding sites in order to be able to detect specific molecules. 8 Furthermore due to its wide band gap, it is well known, that the background current of diamond is very low and the potential window very wide compared to conventional electrodes made from metals or graphite.…”