The Surface Of Fine Boron Powder Coated

Boron-based propellants have excellent energy properties, namely, the highest theoretic specific impulse, but it is difficult to realize it. Now, concerning about the studies of propellants still have some problems, such as the lower quantity about boron power, the lower combustion efficiency of boron, and so on. In order to change the conditions, the most effective method for solving the technics and combustion performances is surface coating of boron power.By the Transmission Electron Microscope,Scan Eelectron Microscope, rotary viscometer X-ray photoelectron spectroscopy, the influence of conditions of coating boron and characterization have been studied, and the influence of coated-boron particles to the technics, combustion properties have been also investigated, and the chemistry analysis for the inflammation residues of boron-based propellants were performed.According to the analysis about boron and coated boron by Transmission Electron Microscope, it was find that the layer existing on the boron particles, and it is well distributed and compact, the thickness of the layer is about 20-50 nano-meters. Scan Electron Microscope also gains the same conclusion. By the analysis of X-ray photoelectron spectroscopy and Transmission Electron Microscope, which show that the surface is perfect, and also the percent of boron element in the surfaces of coated-boron particles is seriously reduced.The results show that coated boron can improve the value of pH of the mixture of HTPB with boron power, and it can effectively reduce the viscosity of propellants, and it also can improve the technics of boron-based fuel-rich propellants. The surface coating of boron improved the content of boron in the propellants, consequently it increased the performance of combustion of boron-based propellants. It's clear that BLiF also reduce the ignition delay time of the boron-based propellants (B/MA/AP/HTPB) from 70.475 sec to 23.585 sec. The determinations ofconcentration of B and B2O3 in the combustion residues of the B/MA/AP/HTPB formulations were performed. It was shown that the B burning efficiency of propellants was obviously improved after the superfine powder coated.