高固含量热固性固体推进剂 3D 打印技术

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 performance 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 material 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.