铝在校正高压下物质弹性波速测量上的应用

APPLICATION OF ALUMINUM IN CORRECTING THE ELASTIC WAVE VELOCITY MEASUREMENT OF MATERIALS AT HIGH PRESSURE

自从在紧装式六面顶高压装置上建立了高温超高压下弹性波速的测量方法之后，已经获得了大量的有关岩石矿物的波速数据，利用这些波速数据解决了许多地质问题。然而，其高压弹性波速数据的精度没有解决，一直无法校正上、下顶砧的真正走时。根据弹性理论和标准物质铝的有关弹性参数，计算出铝的波速与压力的关系，然后，根据铝的波速与压力的关系推导出上、下顶砧的实际走时，校正后测量的较低压力下铁的波速与前人的资料吻合很好，并且铁的波速与压力也具有较好的非线性关系。因而，今后可以根据标准物质铝和铁来校正上、下顶砧的走时，从而获得物质在高压下更加精确的波速数据。

A lot of wave velocity data for minerals and rocks have been obtained since the method of elastic wave velocity measurement has been established in YJ 30MN press fitted with a wedge type cubic anvil at high pressure and high temperature.Many geological problems have been explained by using these velocity data .However,the accuracy of elastic velocity data under high pressure has not been resoved.The travel time of the upper and lower anvils is still not corrected.In this paper we calculate the relation between the velocities and pressures of aluminum according to the elastic theory and elastic constants of aluminum .Then the real travel time of the anvils is infered from the relation between velocities and pressures.The corrected velocities for iron,which is non linear with pressure,is well consistent with other lower pressure data.Henceforward,the real travel time of the anvils can be emended according to the velocities of standard aluminum and iron before experiment.In this way the more accurate velocity data can be obtained under high pressure after corrected.