Diamond films deposited on WC-Co substrates by use of barrier interlayers and nano-grained diamond seeds

Results on the structure, composition and properties of diamond films deposited onto WC-Co cemented carbides via special multilayer barrier interlayers preliminary seeded by nano-grained diamond particles are presented. The barrier interlayers comprise a layer adjacent to the substrate, which completely prevents substrate decarburization and Co diffusion from the substrate, and a diamond-bonding layer needed to obtain an enhanced adhesion of the PACVD diamond coating. Preliminary seeding the barrier interlayers with nano-grain diamond particles by use of a laser ablation technique allows a fine-grained, uniform and highly adherent diamond coating of high quality to be deposited by use of a conventional PACVD technique. Results on the nature of the interaction between the diamond nano-grained seeds and barrier interlayer are also presented.     

Shock-Wave Loading of Amorphous Carbon Nitride in Recovery Ampoules

A small amount of crystalline carbon nitride x-C–N is synthesized under conditions of stepwise shock-wave compression to a pressure of 14 GPa of amorphous carbon nitride obtained by pyrolysis of mercuric thiocyanate Hg(SCN)₂. The x-C–N structure is characterized by the following set of reflections: 3.429 Å (w), 3.147 Å (s), 2.188 Å (s), 2.078 Å (s), 1.919 Å (w), 1.763 Å (w), and 1.560 Å (w). The samples containing x-C–N have clearly defined abrasive properties.