使用TG分析法分析了纯锆粉与包覆了Fe3O4的锆粉(简称包覆锆粉)的静态氧化特性,并利用高速摄像、超细热电偶等技术对纯锆粉与包覆锆粉的燃烧特性开展了实验研究.TG分析显示,相同粒径的包覆锆粉的增重比相对纯锆粉有显著降低.通过对高速摄像图片分析得出,纯锆粉的火焰传播速度大于包覆锆粉的火焰传播速度;且在质量浓度为0.454kg/m3时,二者火焰传播速度的震荡较剧烈;而在质量浓度为0.842kg/m3时,二者火焰传播速度可以实现较为稳定的增长.经过对火焰温度的对比研究可知,在不同的质量浓度下,包覆锆粉的温升与纯锆粉的温升之间存在一个滞后过程.最后对包覆锆粉的燃烧产物进行了XPS分析,测得Fe元素的峰值为709.99,推测其燃烧过程中Fe3O4与Zr可能发生了置换反应.
In this paper, the flame propagation characteristic of the cloud of pure zirconium particle and zirconium particle coated with Fe3O4 was investigated in a square-open tube. According to the results of TG analysis, the weight increase of zirconium particle coated with Fe3O4 is obviously less than that of pure zirconium particle. A high-speed video camera was used to record the images of flame propagation, with which the velocity of flame propagation was calculated. It was obtained that the propagation velocity of zirconium particle coated with Fe3O4 is less than that of pure zirconium particle. The results also demonstrated that their flame propagation velocities are both oscillatory at low concentration (0.454 kg/m3) and steadily increase at high concentration (0.842 kg/m3). Micro-thermocouples were used to obtain temperature profiles, and the temperature rise of zirconium particle coated with Fe3O4 lagged behind that of pure zirconium particle. XPS was used to analyze the combustion products of zirconium particle coated with Fe3O4, and the peak value of Fe was 709.99, which indicated that the replacement reaction of Fe3O4 by zirconium may occur in the flame propagation of zirconium particle coated with Fe3O4.