高固含量热固性固体推进剂3D打印技术OA北大核心CSTPCD

Compared with the traditional solid propellant casting method,3D printing technology possesses higher manufacturing flexibility and safety.For solid propellant materials with high solid content(The mass fraction is greater than 85%),the traditional extrusion printing methods have some problems,such as extrusion discontinuity and poor molding quality,which limit the overall per-formance of the motor.Aiming at the above problems,a dual ultrasonic vibrator resonance extrusion printhead for high solid content thermoset solid propellant was designed based on the principle of ultrasonic anti-friction assisted extrusion.The effects of key process parameters such as printing temperature,extrusion pressure and nozzle diameter on the porosity of the printed propellant ma-terial were investigated.Under the optimal process parameters of printing temperature of 70℃,extrusion pressure of 0.6 MPa,nozzle diameter of ϕ1.7 mm and printing layer height spacing ratio of 0.8,the complex variable burning rate thermosetting solid propellant grain structure with content of 88%,porosity of 3.46%can be printed,printing manufacturing error controlled within 0.4%.At the same time,the tensile strength of the printed sample is improved by 56%than that of the traditional casting sample,which provides a new idea for the manufacture of complex high solid content solid propellant grain structures.