含能材料3D打印实验系统喷头的设计和分析

发布时间：2018-04-05 03:07

本文选题：喷头　切入点：含能材料　出处：《南京理工大学》2017年硕士论文

【摘要】：随着现代武器技术的不断发展,其动力源含能材料的传统成型方式已不适用于加工形状复杂多变的药柱,并且成型过程安全性低,于是需要引进可以自由成型的3D打印加工方式来规避这些问题。本文在基于传统熔融沉积成型机的基础上,考虑到含能材料的安全性问题,提出了含能材料溶剂法3D打印成形,用含能材料代用料进行物料性能的基础研究,设计气压式挤出喷头,旨在实现含能材料的挤出与打印成型。同时就气压与挤出速度之间的预测模型进行研究。开展了含能材料代用料的流变性能基础研究。实验结果表明:在中等剪切速率区间,温度与粘度呈负相关关系,在高剪切速度区间,剪切速率对粘度的影响大。在低温时,溶剂比与粘度呈负相关关系,高温时溶剂比对粘度影响不大。最后对流变数据进行分析、拟合,获取了不同溶剂比与不同温度下的本构模型。进行了含能材料3D打印实验系统喷头的结构设计与制造。成果为:开发了一款气压式挤出喷头,实现了含能材料的挤出,最终搭建了3D打印实验样机。并且对喷头预热情况进行温度分析,发现物料整体受热均匀。实施了入口压力与流道结构参数对挤出速度影响的数值仿真正交试验研究。研究结果表明:入口压力与挤出速度呈正相关关系;成型段长度与挤出速度呈负相关关系;随着收缩角度的增大与喷嘴直径的增加,挤出速度没有恒定的趋势,存在一个最优点使得挤出速度最大。采用试验中获取的结果数据,通过多元线性回归构建了挤出速度与各因素之间的预测模型,并且验证了预测模型的显著性。最后根据预测模型计算得出的挤出速度,匹配打印参数,成功打印出含能材料3D样品。
[Abstract]:With the development of modern weapon technology, the traditional forming method of energetic material of power source is no longer suitable for the processing of complex and changeable shaped powder, and the safety of molding process is low.Therefore, it is necessary to introduce free-forming 3D printing to avoid these problems.In this paper, based on the traditional melt deposition molding machine, considering the safety of energetic materials, the basic research of material performance is presented in this paper, which is based on solvent 3D printing of energetic materials and substitute materials for energetic materials.The pneumatic extrusion nozzle is designed to realize the extrusion and printing of energetic materials.At the same time, the prediction model between pressure and extrusion velocity is studied.The basic research on rheological properties of energetic substitute materials was carried out.The experimental results show that there is a negative correlation between temperature and viscosity in the range of medium shear rate, and the influence of shear rate on viscosity is great in the region of high shear rate.At low temperature, there is a negative correlation between solvent ratio and viscosity, but at high temperature solvent ratio has little effect on viscosity.Finally, the rheological data were analyzed and fitted, and the constitutive models of different solvent ratios and different temperatures were obtained.The structure design and manufacture of the nozzle of 3 D printing experiment system for energetic materials are carried out.The results are as follows: a pneumatic extrusion nozzle is developed, and the extrusion of energetic materials is realized. Finally, a 3D printing experimental prototype is built.The preheating condition of nozzle is analyzed and the whole material is found to be heated evenly.The effects of inlet pressure and runner structure parameters on extrusion velocity were studied by orthogonal numerical simulation.The results show that the inlet pressure has a positive correlation with the extrusion speed, the length of the molding section is negatively correlated with the extrusion speed, and with the increase of the shrinkage angle and the diameter of the nozzle, there is no constant trend of the extrusion velocity.There is an advantage to maximize extrusion speed.The prediction model between extrusion speed and various factors was constructed by multivariate linear regression using the data obtained from the experiment and the significance of the prediction model was verified.Finally, according to the extrusion speed calculated by the prediction model, the 3D samples of energetic materials were successfully printed by matching the printing parameters.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34;TP391.73

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