锆粉粒径对锆/高氯酸钾混合点火药热分解性能的影响

The Effect of Zirconium Particle Size on Thermal Behaviors of Zr/KClO_4 Ignition Powder

通过热重(TG)和差示扫描量热(DSC)实验研究了锆粉粒径对锆/高氯酸钾混合含能体系热分解性能的影响。DSC显示,纯高氯酸钾主要存在3个吸热峰,最后1个峰前有1个小肩峰。加入1μm锆粉后,高氯酸钾中间的吸热峰裂分为1个小吸热峰和1个放热峰,同时使最后1个吸热峰前的肩峰消失,峰形也变得更加尖锐。相比1μm锆粉,-200目(约74μm)锆粉只改变了高氯酸钾的最后1个峰形。运用Kissinger法和Ozawa法计算活化能,发现小粒径锆粉的加入使高氯酸钾的活化能降低了40k J·mol-1,而大粒径锆粉却使其活化能增加了超过1倍。显然,1μm锆粉具有更高的反应活性,其催化效果更明显。

The influence of the zirconium particle size on thermal behaviors of Zr/KCl O4 was studied by use of thermal analysis（TG-DSC）. Without zirconium powder, DSC curves of KCl O4 show three main endothermic peaks and a small acromion in front of the third peak. When added in zirconium powder（1μm）, the middle peak splited into two peaks with one small endothermic peak and the other exothermic peak, however, the last peak became sharp with the small endothermic acromion disappeared. Compared to zirconium powder（1μm）, the zirconium powder（-200 mesh） influenced the last peak only. Within small zirconium grain, the decomposition activation energy of KCl O4 was decreased by 40 k J·mol-1, but increased one more time with large zirconium grain. Obviously, 1μm zirconium powder has a better reactivity than that of-200 mesh powder, so has a more obvious catalytic effect.