Effect of metal hydrides on the burning characteristics of boron

• The effect of some metal hydrides on the burning characteristics of boron is studied for the first time.
• We are the first to conduct a TG experiment on boron samples at high temperatures (a maximum of 1750 °C).
• The thermal reaction process of boron is firstly divided into five stages according to the weight gain rate of the sample.
• Specific values of metal hydrides on ignition delay time and combustion intensity of boron are obtained.

In this study, the effect of four metal hydrides on the burning characteristics of boron was investigated. Thermogravimetric experiment results show that the thermal reaction process of boron samples can be divided into five stages. The thermal reactions of boron can be significantly promoted with LiH, which can reduce the initial temperature of the first violent reaction stage by ∼140 °C. The starting temperature of the post-reaction stage also decreases by ∼260 °C. The results of the laser ignition experiment suggest that all four metal hydrides can promote boron burning. Nonetheless, different metal hydrides display varied promotional effects. Among the studied hydrides, LiH is the most effective additive and shortens the ignition delay time of boron by ∼34.1%. Moreover, it enhances the combustion intensity of boron by ∼117.6%. The other three metal hydrides (CaH2, TiH2, and ZrH2) can also contribute to boron burning.