Confined Pressure Calibration for 3 GPa Molten Salt Medium Triaxial Pressure Vessel under High Pressure and Temperature
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摘要: 新研制的3 GPa熔融盐固体介质高温高压三轴实验系统，改进了高压容器的装样方式以及样品的尺寸，由于装样部件之间摩擦以及克服传压介质本身的强度，视载围压和真实围压具有较大差异，在完成压力容器温度标定的基础上，采用部分熔融法在不同温度和压力条件下进行围压标定实验研究。实验使用LiCl-KCl混合氯化盐样品，分别在300~1 400 MPa视载围压的条件下，对样品进行缓慢加温，成功观测到实验力学数据和温度数据的同时响应，确定了混合氯化盐的初熔温度，通过已知熔融曲线方程计算得出真实围压。通过比较不同的实验条件和观察实验后装样结构，给出了摩擦力的变化规律：在300~500 MPa压力条件下，摩擦力百分比呈现降低趋势，从52%降低到31.2%；在700~1 200 MPa压力条件下，摩擦力约占11.4%；在1 400 MPa压力条件下，摩擦百分比从11.4%上升到15.5%。通过对比国内外同类实验设备摩擦力认为，该设备真实围压的精度达到了国际同类设备的水平。Abstract: A triaxial deformation apparatus with 3 GPa molten salt medium pressure vessel was developed. It is based on the conventional Griggs design and the molten salt cell concept modified. There is a huge difference between apparent confined pressure and true confined pressure due to the friction in the assembly and the strength of the confined medium under high temperature and pressure. In this study, we used the partially molten method of LiCl-KCl to make the confined pressure calibration on the basis of the temperature calibration. We successfully observed the simultaneous variation of confined pressure displacement, axial stress and temperature disturbance when the specimen molten initially, then we calculated the true confined pressure by the given equation. Finally, we obtained a series of true confined pressure under different apparent confined pressure of 300~1 400 MPa. Additionally, we gave a interpretation about the friction in the pressure vessel. When the pressure is at 300~500 MPa, the friction percentage changed from 52% to 31.2% gradually. When the pressure is 700~1 200 MPa, the friction percentage dropped about 11.4%. When the pressure is 1 400 MPa, the friction percentage showed a slightly rise from 11.4% to 15.5%. The true confined pressure of the new pressure vessel is not only more accurate than the old one, it has reached the same level with the similar apparatus in other laboratories of the world.
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Griggs D T. Hydrolytic Weakening of Quartz and Other Silicates [J]. Geophys J R Astr Soc, 1967, 14: 19-31. Han L, Zhou Y S, He C R, et al. Temperature Calibration for 3 GPa Molten Salt Medium Triaxial Pressure Vessel under the High Temperature and Pressure [J]. Chinese Journal of High Pressure Physics, 2009, 23(6): 407-415. (in Chinese) 韩亮, 周永胜, 何昌荣等. 3 GPa熔融盐固体介质高温高压三轴压力容器的温度标定 [J]. 高压物理学报, 2009, 23(6): 407-415. Rybacki E, Renner J, Konrad K, et al. A Servohydraulically-Controlled Deformation Apparatus for Rock Deformation under Conditions of Ultra-High Pressure Metamorphism [J]. Pure Appl Geophys, 1998, 152: 579-606. Beggerow G. Properties of Matter at High Pressures [M]. Berlin: Springer Verlag, 1980. [5] Tingle T N, Green H W, Young T E, et al. Improvements to Griggs-Type Apparatus for Mechanical Testing at High Pressures and Temperatures [J]. Pure Appl Geophys, 1993, 141: 523-543. Bagdassarov N S, Slutskii A B. Phase Transformation in Calcite from Electrical Impedance Measurements [J]. Phase Transitions, 2003, 76(12): 1015-1028. Bohlen S R, Brook S. Equilibria for Precise Pressure Calibration and a Frictionless Furnace Assembly for the Piston-Cylinder Apparatus [J]. N Jb Miner Mh, 1984, H9: 404-412. Bose K, Jibamitra G. Quartz-Coesite Transition Revisited: Reversed Experimental Determination at 500~1200 ℃ and Retrieved Thermochemical Properties [J]. American Mineralogist, 1995, 80: 231-238. Cemic L, Geiger C A, Hoyer W W, et al. Piston-Cylinder Techniques: Pressure and Temperature Calibration of a Pyrophyllite-Based Assembly by Means of DTA Measurements, a Salt-Based Assembly, and a Cold Sealing Sample Encapsulation Method [J]. N Jb Miner Mh, 1990, H2: 49-64. Gleason G C, Tullis J. A Flow Law for Dislocation Creep of Quartz Aggregates Determined with the Molten Salt Cell [J]. Tectonophysics, 1995, 2247: 1-23. -
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