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The hardness of synthetic diamond (70–150 GPa) is very dependent on the relative purity of the crystal itself. The more perfect the crystal structure, the harder the diamond becomes. It has been reported that HPHT single crystals and nanocrystalline diamond aggregates (aggregated diamond nanorods) can be harder than natural diamond. [25]
Other uses include jewellery designing, glass cutting and laceration of diamonds. CBN-coated grinding wheels, referred to as Borazon wheels, are routinely used in the machining of hard ferrous metals, cast irons, and nickel-base and cobalt-base superalloys. They can grind more material, to a higher degree of accuracy, than any other abrasive.
Mineralogical simulation predicts lonsdaleite to be 58% harder than diamond on the <100> face, and to resist indentation pressures of 152 GPa, whereas diamond would break at 97 GPa. [11] This is yet exceeded by IIa diamond 's <111> tip hardness of 162 GPa.
Examining the nature of crystalline bonds they theorised that carbon and nitrogen atoms could form a particularly short and strong bond in a stable crystal lattice in a ratio of 1:1.3, and that this material could be harder than diamond. [3] Nanosized crystals and nanorods of β-carbon nitride can be prepared by mechanochemical processing. [4 ...
Boron carbide (chemical formula approximately B 4 C) is an extremely hard boron–carbon ceramic, a covalent material used in tank armor, bulletproof vests, engine sabotage powders, [2] as well as numerous industrial applications. With a Vickers hardness of >30 GPa, it is one of the hardest known materials, behind cubic boron nitride and ...
Diamond nanoparticles have the potential to be used in myriad biological applications and due to their unique properties such as inertness and hardness, nanodiamonds may prove to be a better alternative to the traditional nanomaterials currently utilized to carry drugs, coat implantable materials, and synthesize biosensors and biomedical robots ...
A <111> surface (normal to the largest diagonal of a cube) of pure diamond has a hardness value of 167±6 GPa when scratched with a nanodiamond tip, while the nanodiamond sample itself has a value of 310 GPa when tested with a nanodiamond tip. However, the test only works properly with a tip made of harder material than the sample being tested ...
Nanophase metals usually are many times harder but more brittle than regular metals. nanophase copper is a superhard material; nanophase aluminum; nanophase iron is iron with a grain size in the nanometer range. Nanocrystalline iron has a tensile strength of around 6 GPA, twice that of the best maraging steels. [1]