醋酸丁酸纤维素对发射药涂覆层低温力学性能的影响

Effects of Cellulose Acetate Butyrate on Mechanical Properties of Coating Layers of Gun Propellant at Low Temperature

为提高发射药涂覆层在低温环境下的力学强度,选择醋酸丁酸纤维素(CAB)和TiO_2粉末作为钝感剂,分别按照不同比例与三胍-15药片(主要组分为NC和NG)混合,用醇酮溶液(乙醇与丙酮体积比为1∶1)配制成涂覆液,进而制成拉伸样品进行拉伸试验,来比较涂覆层与发射药的黏结强度,并通过三维视频观察分析涂覆位置断裂情况;采用端面局部阻燃(阻燃位置为发射药的端面,且发射药内孔保持通气状态)的方法,利用喷涂工艺制备得到涂覆发射药,并进行了密闭爆发器试验,比较分析了不同钝感剂配方涂覆的发射药在不同温度下的L-B曲线。结果表明,在-40℃时,含有TiO_2的涂覆层力学强度较差,在TiO2质量分数为35%时达到相对最大值7.871MPa;而含有CAB的涂覆层黏结强度有所提高,在CAB质量分数为35%时达到9.970MPa。采用CAB作为钝感剂的涂覆发射药在-40℃下的燃烧渐增性相比采用TiO_2时提高了9.278%。

To improve the mechanical properties of coating layer of gun propellant at low temperature environment, selecting cellulose acetate butyrate fCAB） and TiO2 powder as desensitized agents, cellulose acetate butyrate fCAB） and TiO2 powder were mixed with triguannidine 15 absorption propellant tablets fmain component is nitrocellulose and nitroglycerin） according to different proportion respectively and the coating liquid was prepared by ethanol ace tone solution fthe volume ratio of ethanol and acetone is 1 ： 1 ）. Then, tensile samples were made for the tensile ex periments to compare the bonding strength of coating layer and propellant, and the fracture situation of coated posi tion was observed and analyzed by 3D video. Using the local flame retardant fflame retardant position is the end face of propellant and propellant hole maintains ventilation state） method of end face, the coated gun propellant was pre pared by spraying. The closed bomb experiments of propellant grains were performed. The L B curves at different temperatures of coated propellants coated by different desensitized agent formulation were compared and analyzed. The results show that at 40℃, the mechanical strength of coated propellants with TiO2 is poorer. When the mass fraction of TiO2 reaches 35%, the pressure reaches a relative maximum of 7. 871 MPa, while the adhesive strength of coating layers with CAB increases. When the mass fraction of CAB is 35%, the adhesive strength of coating lay ers reaches 9. 970 MPa. The combustion progressity of the coated propellant with CAB as desensitized agent at 40℃ increases by 9. 278% when compared with the use of TiO2.