双基发射药挤出式3D打印技术

Extrusion 3D Printing Technology of Double base Gun Propellants

为了研制复杂几何形状的发射药,采用双基发射药挤出式3D打印工艺,通过螺杆挤出式发射药3D打印机打印出方形、车轮形、星孔形和花边七孔双基发射药,对打印发射药的表面结构、尺寸均匀性、密度和力学性能进行表征。结果表明,打印发射药的表面较光滑、无明显瑕疵;花边七孔发射药的尺寸均匀性达到传统方式制备发射药的标准,车轮形发射药弧厚的尺寸均匀性较好,标准偏差为0.026 mm,相对标准偏差为0.92%;方形发射药的密度较高(1.567 g·cm^(-3)),其他发射药的密度为1.549~1.559 g·cm^(-3);打印填充路径为同心线(填充线方向与拉伸方向平行)和直线(填充线方向与拉伸方向垂直)的发射药试样的拉伸强度分别为14.467 MPa和10.789 MPa,前者与传统方式制备的发射药拉伸强度相当。实现具有弧度和角度的多种几何形状发射药的良好打印为复杂几何形状发射药的制备提供了基础。

In order to prepare gun propellants with complex geometries,the extrusion 3D printing process of double base gun propellants was proposed.Square-shaped,wheel-shaped,star hole-shaped and lace seven hole double base gun propellants were printed by screw extrusion gun propellants 3D printer.The surface structure,size uniformity,density and mechanical property of the printed gun propellants were characterized.The results show that the surface of the printed gun propellants is smooth without obvious defects.The size uniformity of lace seven hole gun propellants reaches the standard of traditional gun propellant preparation process,and the size uniformity of arc thickness for wheel-shaped gun propellant is good,with a standard deviation of 0.026 mm and a relative standard deviation of 0.92%.The density of square-shaped gun propellant is higher(1.567 g·cm^(-3))than those of other gun propellants(1.549-1.559 g·cm^(-3)).The tensile strength of gun propellant samples with concentric filling path(the filling line direction is parallel to the tensile direction)and straight line(the filling line direction is perpendicular to the tensile direction)are 14.467 MPa and 10.789 MPa,respectively,the former is equivalent to that of gun propellants prepared by traditional extrusion process.The good printing of multi geometry gun propellants with radians and angles provides a basis for the preparation of complex geometry gun propellants.