EXPERIMENTAL STUDY ON THE ε-γ PHASE TRANSITION OF HNIW INDUCED BY HEAT STIMULATION

摘要

The ε-γ phase transition of HNIW was investigated with in-stiu X-ray power diffraction (PXRD) by heat stimulation. The effect of purity, particle size, insensitive additives and the time of isothermal heat treatment were evaluated in real time. It is found that the phase transition is irreversible during the process of the temperature rise and drop, and two phases can coexist in the range of a certain temperature. Moreover, the phase transituion are related to particle size and purity, the higher purity and smaller particle size (approximate density), the higher initial phase transition temperature is. When mixed with graphite and praffion wax, with the proportion of insensitive additives, the initial phase transition temperature decreased correspondingly, but TATB is a suitable insensitive additive, owing to the neglectable influence in phase transition. And that the critical temperature reached, isothermal time determined the efficiency of E- to y-phase transition.