The Discharge Structure Design And Forming Accuracy Analysis Of The 3D Printing Experiment System For Energetic Materials

With the development of various rapid prototype(RP)technology and complex request of the energetic propellant from modern weapons,the 3D printing technology has entered the energetic material forming territory.This paper,which aims at the 3D printing technology of energetic material,designed and optimized the feeding system based on the pneumatic prototype.Simulations about substitution of energetic material have been done with POLYFLOW to present a new shape of running which can decrease the expansion of material after being extruded.At last,the forming experiments with the optimized printer were made to check the influence of the different parameters.The new energetic material 3D printer is based on the pneumatic prototype.The control of extrusion has been changed into stepping motor and the feeding system was redesigned.Researches about the expansion of the material after being extruded were studied.A runner in shape of curve has been simulated with POLYFLOW and tested in experiments.After the comparisons among size of expansion,distribution of velocity and pressure,it turns out that runners in shape of curve can decrease the size of expansion under same circumstances.To check the heat distribution while in preheating,simulations about the process of reheating were made in Ansys and the better way was chosen.Besides,the parameters of the nozzles that would affect the expansion were simulated in POLYFLOW.After the comparisons among contraction ratio,length of the molding part and velocity of inflow,the contraction ratio was found to affect the expansion of cone nozzle most and a preference range existed.The impact trend of length of molding part would decrease after increasing for a while.The tendency of inflow velocity was similar to the expansion.With the combination of simulation and experience from experiments,a better series of parameters about the nozzle was selected.After the simulation part,a large amount of molding experiments which aim at the height,degree of density and strength of extension were made based on the orthogonal analysis.The affecting parameters are ration between velocity of platform and extrusion,layer thickness,shape of nozzle and scanning trace.The results were finally analyzed and the most preferential printing parameters which would affect the accuracy most were decided.