Bondar Dmitry, Fei Hongzhan, Withers Anthony C, Ishii Takayuki, Chanyshev Artem, Katsura Tomoo
Bayerisches Geoinstitut, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
Center for High Pressure Science and Technology Advanced Research, Beijing 100094, China.
Rev Sci Instrum. 2021 Nov 1;92(11):113902. doi: 10.1063/5.0062525.
We report a new rapid-quench technique for the Kawai-type multi-anvil press: several important improvements were made to our previous design. As a result, we are able to routinely quench melts with low glass-forming ability and form glasses. Owing to the use of 3D-printed parts to supply the coolant, the new design is easier to assemble and demonstrates better temperature stability and cooling rate. It was also found that the cooling rate is both pressure- and temperature-dependent. The cooling rate increases with increasing pressure from 6700 °C/s at 1 GPa to 8200 °C/s at 5.5 GPa and decreases with increasing temperature at a rate of 550 °C s/100 °C. Taking these dependencies into account, the new rapid-quench design produces more than 15% higher cooling rate compared to the previous design. Moreover, enhancing coolant circulation, which was achieved by using tapered inner anvils with holes, additionally increases the cooling rate by about 4%. As the structure of the rapid-quench assembly differs dramatically from other existing designs, pressure calibration and temperature distribution in the experimental cell and sample capsule were determined for the first time. It was found that the first 0.6 MN of press load is not used to generate pressure due to the hard tungsten components in the assembly. At the current state-of-the-art, it is possible to routinely reach a pressure of 9 GPa and a temperature of 2200 K with the temperature variation not exceeding 70 K within the sample capsule.
对我们之前的设计进行了几项重要改进。结果，我们能够常规地淬火玻璃形成能力低的熔体并形成玻璃。由于使用3D打印部件来供应冷却剂，新设计更易于组装，并且具有更好的温度稳定性和冷却速率。还发现冷却速率与压力和温度有关。冷却速率随着压力从1 GPa时的6700℃/s增加到5.5 GPa时的8200℃/s而增加，并随着温度以550℃/100℃的速率增加而降低。考虑到这些相关性，新的快速淬火设计比之前的设计产生的冷却速率高出15%以上。此外，通过使用带孔的锥形内砧实现的冷却剂循环增强，使冷却速率额外提高了约4%。由于快速淬火组件的结构与其他现有设计有很大不同，首次确定了实验腔和样品胶囊中的压力校准和温度分布。发现由于组件中的硬质钨部件，压机负载的前0.6 MN不用于产生压力。在当前的技术水平下，常规情况下可以达到9 GPa的压力和2200 K的温度，样品胶囊内的温度变化不超过70 K。
