New record: Ultrahigh pressure generation in walker-type press
image: (a) 650 bar and 2000 K in an 8/3 assembly; (b) 650 bar and 2000 K in a 7/3 assembly; (c) 450 bar and ∼2100 K in a 6/1.5 assembly with tapered anvils; and (d) 600 bar and ∼1950 K in a 6/1.5 assembly with tapered anvils. Brg: bridgmanite; Cor: corundum.
Credit: Xuyuan Hou et al.
In a recent study published in Engineering, researchers from Jilin University have achieved a significant breakthrough in high-temperature ultrahigh pressure generation using a Walker-type large-volume press (LVP). This advancement has opened new avenues for exploring novel materials and understanding Earth’s interior.
The team successfully generated pressures ranging from 37.3 to 40.4 GPa at temperatures between 1900 and 2100 K. They achieved this by employing newly designed ZK01F tungsten carbide (WC) anvils with tapered surfaces. These anvils, along with cell assemblies containing hard materials and a sample volume of approximately 1 mm³, were crucial in expanding the pressure range. Additionally, specific adjustments to the apparatus enhanced its performance.
The study also investigated the pressure efficiencies of different WC anvils and cell assemblies. Through meticulous experimentation, the researchers were able to optimize the setup for higher pressure generation. They compared the new-ZK01F anvils with other commercial hard carbide anvils, such as Fujilloy F08 and Hawedia, analyzing their mechanical properties and performance under high pressure.
The applications of this ultrahigh pressure technology are far-reaching. In materials science, the team synthesized and characterized bulk samples of nearly pure sp³-hybridized ultrahard amorphous carbon. These samples exhibited remarkable properties, including high hardness and tunable band gaps. Core–shell nanocrystals with high Néel temperatures were also synthesized, showing potential for applications in information storage and sensing.
In Earth science, the researchers studied the solubility of water and oxygen vacancies in lower mantle minerals. By synthesizing large-sized single crystals of lower-mantle minerals, they gained insights into the composition and structure of Earth’s interior. This could help explain phenomena such as mid-lower-mantle slab stagnation.
The researchers believe that with further advancements, the Walker-type LVP could reach even higher pressures, enabling more in-depth studies of materials and Earth’s interior. The broader range of feasible pressures and temperatures in LVPs holds great promise for future scientific and industrial applications.
The paper “Ultrahigh Pressure Generation at High Temperatures in a Walker-Type Large-Volume Press and Multiple Applications,” authored by Xuyuan Hou, Yuchen Shang, Luyao Chen, Bingtao Feng, Yuanlong Zhao, Xinyu Zhao, Kuo Hu, Qiang Tao, Pinwen Zhu, Zhihui Li, Ran Liu, Zhaodong Liu, Mingguang Yao, Bingbing Liu. Full text of the open access paper: https://doi.org/10.1016/j.eng.2023.03.023. For more information about the Engineering, follow us on X (https://twitter.com/EngineeringJrnl) & like us on Facebook (https://www.facebook.com/EngineeringJrnl).