HTPB复合固体推进剂细观结构微CT试验研究

Micro-CT Experimental Study on the Mesostructure of HTPB Composite Solid Propellant

为研究HTPB推进剂的细观结构及固体颗粒在推进剂中的分布规律,采用高精度微CT对HTPB推进剂不同截面进行了扫描试验,获取了推进剂的细观形貌,对推进剂中细观缺陷和固体颗粒进行了定量表征。结果表明,AP颗粒呈三级配填充于基体中,Al颗粒填充于AP颗粒之间,推进剂细观颗粒填充存在局部不均匀现象;推进剂内部的缺陷除了颗粒/基体界面初始脱粘,AP颗粒本身也存在孔洞或者微裂纹;AP颗粒、Al颗粒和孔洞的尺寸都较好地服从Weibull分布;在1500μm×1500μm的选定区域内,AP颗粒、Al颗粒和孔洞面积占比的平均值分别为0.521、0.079和0.015;推进剂宏观断裂是AP颗粒脱湿后形成孔洞不断汇合的结果,在断面上存在大量颗粒脱湿留下的凹坑,也有大量AP颗粒暴露在外面。

To study the mesostructure of HTPB propellant and the distribution of solid particles in the propellant,a high-precision micro-CT was used to scan different cross sections of HTPB propellant,and the mesomorphology of HTPB propellant was obtained.The defects and solid particles in the propellant were quantitatively characterized.The results show that AP particles are filled in the matrix in three grades,and Al particles are filled in the gaps between AP particles,there is local inhomogeneity in the filling of propellant particles.In addition to the initial debonding of the particle/matrix interface in the internal defects of propellant,there are holes or microcracks in AP particles as well.The sizes of AP particles,Al particles and pores all obey the Weibull distribution well;In the area of 1500μm×1500μm,the average proportions of AP particles,Al particles and hole areas are 0.521,0.079 and 0.015,respectively.The macro fracture of propellant is the result of the continuous coalescence of pores formed by the dewetting of AP particles.There are a large number of pits left by dewetting of particles on the cross section,and a lot of AP particles are exposed outside.