| According to the feature of unit cartridge case charge,a kind of new combustible cartridge case（NCCC）was manufactured by solution impregnation method.Content of each element of main component was tested by elemental analyzer and Oxygen balance of NCCC was calculated for-92.83%.The microstructures of NCCC and suction molding combustible cartridge case（SMCCC）were investigated by gas adsorption and desorption analyzer and SEM,results show that pore numbers of NCCC were few and pore numbers of SMCCC were rich.Specific surface areas of NCCC was 0.88 m2·g-1 and specific surface areas of SMCCC was 1.68 m2·g-1.Mechanical test result show that the tensile strength of NCCC increased 188%and the compressive strength increased 51%compared with SMCCC.The tensile strength of NCCC decreased in high and low temperature.Thermal analysis experiments show that thermal decomposition process of NCCC and SMCCC were divided into four processes.NCCC exists about 8ms ignition delay phenomenon,burning end time was 167.5 ms,explosive force was 218.54 J·g-1.Burning end time of SMCCC was 5.33 ms and explosive force of SMCCC was 609.36 J·g-1.With the increasing of charge density,ignition pressure and temperature,the burning speed of NCCC accelerated.With the increasing of NCCC,the pressure rised slowly,maximum pressure droped,burning end time delayed in mixed charge composed of NCCC and AGu 7/7H.When the percentage of NCCC is from 0%to 60%in mixed charge,the combustion residues in closed bomb were less and less.When the percentage of NCCC is from 60%to 80%in mixed charge,the combustion residues in closed bomb were more and more.Considering the energy release,combustion progress and combustion completion,the combustion matching between AGu 15.5/19 and NCCC was better than it between AGu 14.5/19 and NCCC,the combustion matching between AGu 13/19HB and NCCC was better than it between nitramine powder 14/19HB and NCCC.The date of ballistic test was perfect,NCCC burned completely and had no residues and it can meet the the classify requirements of howitzer. |
