Novel High Pressure Multi-Anvil Device for Diamond Production

Abstract

The synthesis of diamond crystal from powder mixture of graphite and catalyst alloy is a well known process but it is limited to relatively small crystal dimensions due to the size of the conventional compression chambers. In this work the design and construction of a novel high pressure multi-anvil device with a parallelepiped shaped compression chamber is presented. The design allows the length of the chamber to be limited only by the working space of the press equipment. A four horizontal anvils device was constructed for a specific 2500 ton press with a 600mm working space. The efficiency of this construction was tested in diamond crystal synthesis.

Performance of Nanostructured Diamond Composites in Wear Tests

“…The sintering of diamond particles to produce compacts, such as inserts for abrasive tools, is usually performed inside high pressure devices (HPD) with the application of both, high pressure and high temperature (HPHT) conditions. These HPHT conditions, where diamond sintering can be achieved, have already been determined [1][2][3][4][5][6]. However, under the conventional HPHT conditions the diamond particle displays low plasticity, which explains the difficulty in producing well consolidated compacts [3].…”

“…These HPHT conditions, where diamond sintering can be achieved, have already been determined [1][2][3][4][5][6]. However, under the conventional HPHT conditions the diamond particle displays low plasticity, which explains the difficulty in producing well consolidated compacts [3]. Actually a good consolidation of diamond compacts requires not only the elimination of existing pores formed in between adjacent particles but also convenient technical processing to avoid the graphitization of diamond particles [4].…”

“…Recent studies [9] have shown that nanostructured diamond-SiC composites exhibit an even superior improvement in mechanical properties, especially the toughness. In the present study, nanostructured composites were produced in the diamond-Si and not the already investigated [3] diamond-SiC system. Cyclic application of the pressure and temperature was also a novel procedure to evaluate the wear performance of the final sintering product.…”