不同加载压力下平面对顶砧间叶蜡石封垫力学状态的演变

Evolution of the Mechanical Behavior of Pyrophyllite Gasket between Flat Anvils under Different Loading Pressures

以Wakatsuki提出的恒定加载压力下封垫的压缩模型为基础,采用直径20mm的硬质合金平面对顶压砧,测量了不同外部加载压力下叶蜡石封垫的临界厚度、弹性区半径以及回弹率等数据;结合对中心压力的标定,以及对回收封垫的图像处理分析和相关计算,给出了封垫内弹性区和塑性区的压力分布随外加压力变化的规律,并估算了准静水压区范围。实验表明:平面对顶压砧间封垫塑性区内的剪切强度随压力提高而增加,中心的压力随外加压力的提高而增加,其增加的比率具有逐渐上升的特点。

On the basis of the compressible gasket model presented by Wakatsuki,we investigated the squeezing behavior of a pyrophyllite gasket using a Bridgman type high pressure apparatus with an anvil top diameter of 20 mm. A series of data including the critical thickness, the elastic region diame- ter,the compression spring-hack rate etc. , were measured under different loading forces. Combining with the pressure calibration at the center of the gasket, the image-analysis＇of recovered discs and related calculations, we described the evolution of the mechanical state and pressure distribution in the elastic and plastic regions of gasket along with the increase of the loading force, and then estimated the region of quasi-hydrostatic pressure in the gasket. The experimental results show that the increase rate of the center pressure with the loading force shows an upward trendency, which is a feature of the Bridgman anvils.