The Radial Variable Density Ball Flat Drugs Preparation Process And Combustion Performance Study

A new type of radial variable density oblate spherical propellant powder (VDSP) with porous structure inside and high-density outside in same materials was designed to be used in small-caliber guns on the basis of analyzing how to implement burning progression. This special structure makes the VDSP have a higher burning progression. The preparation process of the VDSP was focused on.Two-step-method was put forward to be used for preparation VDSP. The first step is to get the porous spherical propellant powder which has low-density; The second step is to make surface layer of the porous spherical propellant swell, then drive the solution and dehydrate swelling layer to get the target VDSP. The result shows that the bulk density of the porous spherical propellant powder can be varied by adjusting dehydrating agent strength in the first step; solvent quantity and swelling time have a great effect on the thickness of the shell, the bigger the solvent quantity is and the longer the welling time is, the thicker the shell will be. When the temperature of the roller of the mangier is between 80℃and 90℃, homogeneous thickness of the VDSP can be gained in the process of calendaring avoiding danger and the changes of the VDSP's physical structure. The closed bomb burning experiments shows that the dynamic activity of the sample is bound up with the density of the sample, lower density the sample is, higher dynamic activity the sample will be. The sample also shows a higher burning progression in the combustion process as a result of its special structure, the thinner the shell and the lower the core is, the higher the burning progression is. At the same time, different degrees of the burning progression were achieved by adjusting density of the core and thickness of the shell. Interior ballistics experiments show that VDSP has broad application prospects by designing reasonable size and structure.