FOX-7在α→β相变过程中的特性

α→βPhase Transition Characteristics of High-Energy and Low-Sensitivity Explosive FOX-7

为了解新型高能低感炸药FOX-7的α→β相变具体过程,采用扫描电子显微镜、在线热台仪和显微共聚焦拉曼测试等方法,从晶体的宏观结构和微结构角度详细研究了α→β相变过程中晶体的变化情况,探究了升温速率、晶体形貌和晶体缺陷等不同因素对相变的影响。结果表明:在α→β相变过程中,相变是从晶体的某一缺陷处开始逐步扩散至整个晶体;晶体尺寸、升温速率和晶体形貌对相变有不同程度的影响,晶体尺寸越大、升温速率越慢、晶体外形呈块状时相对更易于发生相变,但差异并不明显;晶体发生相变后经常会出现裂纹、破碎、透明度降低等现象。采用多巴胺原位聚合包覆FOX-7晶体可以在一定程度上延缓α→β相变的发生。

In order to understand the specific process ofα→βphase transition in FOX-7,some experimental methods are used to analyze theα→βphase transition,such as scanning electron microscope,THMSG600 heating stage instrument,and micro-confocal Raman spectrum.The changes of the crystal morphology during theα→βphase transition in FOX-7 are studied at the overall and individual levels of the crystal in detail.At the same time,the effects of different factors such as heating rate,crystal morphology,and crystal defects ofα→βphase transition are explored.The results show that during theα→βphase transition,cracks and breakages appear in the crystals,and the crystals become opaque.Meanwhile,it was found that the crystal size,heating rate,and crystal morphologies have effects on the phase transition in different degrees.It is relatively more prone to phase change in the case of larger massive crystals under a slower heating rate.Besides,the phase transition ofα→βis a continuous process,and it gradually diffuses from a certain defect to the entire crystal.For this reason,in-situ polymerization of dopamine can be used to coat FOX-7 crystals to achieve the purpose of inhibiting theα→βphase transition.