Operation of large-volume cubic press above 8 GPa and 2500°C with a centimeter-sized cell volume using an optimized hybrid assembly

• Published in: High pressure research Vol. 41; no. 2; pp. 132 - 141
• Main Authors: Song, Guozhu, Ma, Dejiang, Zhou, Xuefeng, Wang, Lingfei, Wei, Zheng, Xu, Chao, Wang, Wendan, Wang, Liping, Zhao, Yusheng, Wang, Shanmin
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 03.04.2021; Taylor & Francis Ltd
• Subjects: Anvils; Assembly; Cubic press; Design optimization; high pressure; hybrid cell assembly; Industrial applications; Pressure cells; Pyrophyllite; superhard materials
• ISSN: 0895-7959; 1477-2299
• DOI: 10.1080/08957959.2021.1897983

Large-volume cubic presses are widely used in scientific research and industrial applications. However, their pressure capability is often limited to 6 GPa, which severely restricts their applications under extended pressures. In this work, we report a newly designed hybrid cell assembly for cubic presses by embedding six WC pressure-enhancing blocks into the pyrophyllite pressure-transmitting medium, leading to profoundly increased pressure efficiency (i.e. more than 40%), hence largely extended pressure conditions up to 8-9 GPa without sacrificing sample volume. Because of the optimized design, the expensive first-stage WC anvils are effectively protected, which makes the press routinely operated up to 8-9 GPa in avoiding damage of anvils. Through optimization of heating efficiency, temperature of the new assembly can reach above 2500°C. Using this high pressure cell, we have synthesized centimetre-sized polycrystalline cubic BN bulk sample by the direct transformation of hexagonal BN at 7.7 GPa and 2000°C. Successful implementation of large-volume cubic press up to 8-9 GPa and 2500°C would provide many opportunities for the synthesis of new materials on massive scale (e.g. novel superhard compounds) and for the study of materials at extended pressures.