利用围压提高二级大腔体静高压装置压力极限的初步实验探索

Preliminary Experiment Exploring for Improving Pressure Limit of Two-Stage Hydrostatic High-Pressure Apparatus Using Confining Pressure

采用基于国产铰链式六面顶压机二级6-8型大腔体静高压装置中的10/4(即八面体传压介质边长为10mm,二级WC-Co硬质合金立方块截角边长为4mm)组装,选择不同的围压材料和传压硬质合金台棱、圆片,在室温下用ZnTe的高压相变对压腔进行了压力标定。实验结果表明,叶蜡石是较合适的围压材料;但由于传压台棱、圆片自身强度的限制,及一级压腔形成的围压值较低等原因,致使实验没有达到预期的末级压砧围压增强效果。通过结合两种压腔的力学简化模型分析得知,围压材料与二级增压装置的预密封边共同形成了二级压腔的密封边,该大面积密封边消耗了系统的大部分加载力,因此在围压实验中没有观测到二级6-8型大腔体静高压装置压力极限的提高。

In this study,we choose different confining pressure materials,pressure transmitting WC-Co platforms and WC-Co wafers,to calibrate pressure of 10/4(The edge length of octahedral transmitting pressure medium is 10mm/the truncated angle edge length of WC-Co cemented carbide anvil is4mm)assembly of two-stage 6-8type hydrostatic high-pressure apparatus based on the hinge-type cubic-anvil 6×8 MN press at room temperature,using phase transition of ZnTe under high pressure.The experimental results show that the pyrophyllite is a relatively ideal confining pressure material,but it can not pressurize obviously because of the strength limitations of platforms and wafers.By combining simplified mechanics model of 2kinds of presses,we also find out that the large-area gasket,formed by pre-gasket and initial confining pressure material together,consumes most of the loading,and the gap is oversized between the first anvils.Therefore,we did not observe any improvement of the10/4assembly pressure limit in our experiments.