Metastable intermolecular composite (MIC) Al/Bi₂O₃ has good features of high combustion efficiency, fast energy releasing rate, high pressure pulse, good safety performance and being environment-friendly. It shows good application prospects in pyrotechnics, explosives and propellants, etc. In this review, reaction mechanisms and models, preparation and applications of the metastable intermolecular composite Al/Bi₂O₃ are summarized. First, various theories and models which were used to explain the reaction mechanism of thermites are introduced and compared. The models of the CJ(Chapman-Jouguet) detonation and thermal equilibrium which could interpret and simulate output pressure of Al/Bi₂O₃ reasonably are discussed in detail. Second, the preparing methods of Bi₂O₃ and Al/Bi₂O₃ are summarized. By using different preparing processes, the morphologies, microstructures and combustion performances of composites could be regulated. Meanwhile, the effects of reactants particle size and various additives in preparing Al/Bi₂O₃ on its combustion performances are analyzed. Furthermore, a brief introduction of the application research is also presented. Finally, we proposed prospects about the metastable intermolecular composite Al/Bi₂O₃.

Contents
1 Introduction
2 Thermite reaction mechanism
2.1 Ignition mechanism
2.2 Pressure generation model
3 Preparation methods
3.1 Preparation of nano Bi₂O₃
3.2 Preparation of nano Al/Bi₂O₃
4 Performance tuning of Al/Bi₂O₃
4.1 Particle size of material
4.2 Additive
5 Applications of Al/Bi₂O₃
5.1 Initiating explosives
5.2 Miniature initiating explosive devices
5.3 Propellants
6 Conclusion and outlook