机械球磨法制备Al/C复合粒子及其对HTPB推进剂的性能影响

为了提高Al粉的活性和燃烧效率，采用机械球磨法制备了一种Al/C复合粒子并优化了球磨条件，当C质量分数为30%、球料比为14、转速为350 rad·s-1、环境介质为正己烷、湿磨时间为2 h时，复合粒子中Al和C的晶粒尺寸分别为33.2 nm和42.5 nm，粒子的相对有效活性为70.33%.同时，研究了复合粒子对HTPB推进剂的黏度、力学、爆热、燃速等的影响.研究结果表明，复合粒子会增加HTPB推进剂的黏度，但是体系是一个典型剪切变稀的流体，复合粒子加入量越多，剪切变稀程度越大，因此选择合适的添加量和加工条件，含复合粒子的推进剂能高质量成型；且复合粒子能有效改善HTPB推进剂的力学强度，当其替代Al粉比例从0%增加到30%，平均最大拉伸强度和断裂强度分别从0.37，0.32 MPa增加至0.75，0.69 MPa；且复合粒子的替代量为15%时，HTPB推进剂的爆热和燃速分别较空白提高9.91%和48.27%. 

Preparation of Al/C Composite Particles by Mechanical Milling and Its Effect on Property of HTPB Propellants

In order to improve the activity and combustion efficiency of aluminum powder,a mechanical ball milling method was used to prepare Al/C composite particles and the milling conditions were optimized. The results show that,when the carbon content is 30%,the ratio of balls mass to powder mass is 14,the rotating speed is 350 rad/s,hexane is used as an inert atmosphere and the milling time is 2 hours,the sizes of Al and C in the composite particles are 33.2 nm and 42.5 nm respectively,the relative effective activity can reach up to 70.33%. The effects of composite particles on the viscosity,mechanics,explosion heat,burning rate and other properties of composite propellant were studied respectively. The results suggest that composite particles can increase the viscosity of HTPB propellant,but the system is a typical shear thinning fluid. The more composite particles are added,the greater the degree of shear thinning will be. Therefore,the propellants containing composite particles can be formed with high quality by selecting appropriate addition amount and processing conditions. And particles will improve the mechanical strength of HTPB propellant. When the particles content increases from 0% to 30%,the average maximum tensile strength and fracture strength enhance from 0.37 MPa and 0.32 MPa to 0.75 MPa and 0.69 MPa respectively. In addition,composite particles can significantly improve the explosive heat and burning rate of the propellant. For example,taking 15% composite particles as the replacement amount,the explosive heat and burning rate can be increased by 9.91% and 48.27%,respectively,compared with the blank.