At present,Guest Posting though coating, adhesives, reunion and other methods, China solves the technology problem of low-purity boron powder application in the fuel-rich propellant. But the amount of coating boron powder is limited in propellant and particle control technology of reunion boron powder is difficult. It impacts on the fuel-rich propellant performance. In addition, there are also technical problems of process complexity and poor reproducibility.
In recent years, China developed a high-purity boron 20/28 powder for sale powder, the surface of B2O3 and H3BO3 content is very small, direct for HTPB boron-rich fuel propellant formulations, will not only avoid the application of low-purity boron powder burn performance and energy properties. Abroad in the 1970s to carry out too high-purity crystalline boron powder applied research, compared the impact of 10um of crystalline boron powder and amorphous boron powder on the fuel-rich propellant burning rate and particle size on the burning rate is not obvious. Of course, the fuel-rich propellant burning rate on boron powder particle size effects have different results. Containing small particles of high purity boron powder propellant burning rate higher than with low-purity boron powder propellant burning rate. Different particle size and purity manganese powdersignificantly different impact on the propellant burning rate, it is necessary to research the combustion characteristics of the high purity boron powder. At present, the morphological characteristics of the domestic high-purity boron powder used in fuel-rich propellant combustion performance and energy performance, the technological foundation for the application of high-purity boron powder and solid rocket ramjet engine developed.
Purity boron powder, most of the particles is irregular, but at the micro-crystalline structure. Of H3BO3 impurities is very small due to high purity boron powder surface of B2O3, boron powder with water suspension pH values close to neutral, the yield value and apparent viscosity of boron powder in the HTPB binder is smaller, and with the increase in mixing time the yield value and apparent viscosity remains unchanged. Rich fuel propellant thermal decomposition process of mass loss within the range of 290 ~ 407 ° C high-purity boron powder can be qualitatively high-purity boron powder in the condensed phase reaction activity higher than that of amorphous boron powder. Normal combustion of the fuel-rich propellant at low pressures with high-purity boron powder, the combustion characteristics of amorphous boron powder, heat of combustion and higher combustion efficiency.
In the BH, content of single B is about 97.88%. The particle size is 2 to 5um.Most of the particles is irregular with micro crystal structure. Due to the little impurity of H3BO3 and B2O3 on BH surface, suspension PH value of boron powder and water is close to neutral. The yield value and apparent viscosity of bronze powder (FCu 663) is small in the HTPB binder and increases according to the mixing time. The yield value and apparent viscosity remains unchanged. The fuel-rich propellant of BH can have normal combustion under low pressures situation. The heat of combustion and combustion efficiency is relatively high. BH and BL have same impacts on the propellant burning. But it is more active than the BL involving in the condensed phase reaction. Source: