静水压加载单晶MgO的超声测量与压力标定

通过对单晶MgO的高压声速测量,结合高压Brillouin散射数据,对静水压加载条件下六面顶压机高压腔中的压力进行了多点系统标定(系统油压从15 MPa到51 MPa,间隔2 MPa),建立了新的大腔体压机超声测量和压力标定技术。相比传统的仅采用2~3个标定压力点的方法,该技术在统计上更加可靠。结合LY12铝的高压声速测量,进一步验证了该压力标定方法的合理性。与固体传压组装相比,固液混合传压组装在相同油压下的压力值系统偏低,分析认为这主要是由于固体传压介质中的剪切效应导致标定压力值系统偏高造成的。

Ultrasonic Velocity Measurement and Pressure calibration of Single Crystal MgO under Hydrostatic Pressure Load

By measuring the sound velocity of single crystal MgO at high pressures and using the high pressure Brillouin scattering data, the pressures point by point (the oil-pressure points range from 15 MPa to 51 MPa with step of 2 MPa) in a wide pressure range in the cubic pressure cell under hydrostatic loading environment were calibrated. Furthermore, a novel pressure calibration technique for the large volume pressure cell was established. This new calibration method is more reliable than the traditional one which only depends on 2 or 3 phase transition points. As an example, the measured sound velocity in LY12 aluminum under this hydrostatic loading is in good agreement with published literature data, which further confirms that the novel pressure calibration method is feasible and reliable. Comparing the pressure in the high-pressure cell based on the solid-liquid hybrid assembly with that based on the all-solid one, it was found that the cell-pressure in the former is systematically lower. The analysis suggested that this phenomenon is due to the shear effect in all-solid assembly which makes the pressure scale much higher.