Dynamic and static electrical characteristics of micro-surface of rocks by coupled use of Atomic Force Microscope and micro-loading device

Abstract

In order to further explore the mechanism of electromagnetic radiation of coal and rock during loading, the change characteristics of electrical parameters including surface potential and charge density of the four types of rocks under dynamic and static conditions were assessed and tested using Atomic Force Microscope (AFM) and Micro-loading device. The results show that under static conditions, the micro-surface potential of the four rocks ranges between −922 mV and 235 mV, and the micro-surface potential has a good correlation with the charge density of the same type rock; under dynamic conditions, the micro-surface potential of the rock increases constantly with the loading, the range of the average value of the electric potential is −0.366∼1.188 V, and the micro-surface potential is positively correlated with the load, which has an obvious force-electric coupling effect. This work reveals the electrical characteristics of rock micro-surface under dynamic and static loading conditions, which may provide important experimental basis for further revealing the microscopic mechanism of electromagnetic radiation and improving theoretical system of electromagnetic radiation.